NilsML/retriever_dataset · Datasets at Hugging Face

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What is the name of matter that mechanical wave energy can only travel through?	weight	form	solid	medium	The energy of a mechanical wave can travel only through matter. This matter is called the medium ( plural , media). The medium in Figure above is a liquid — the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. It’s important to note that particles of matter in the medium don’t actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and-forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on.
What is able to occur because no surface is perfectly smooth?	temperature	mass	tension	friction	Friction occurs because no surface is perfectly smooth. Even surfaces that look smooth to the unaided eye appear rough or bumpy when viewed under a microscope. Look at the metal surfaces in Figure below . The metal foil is so smooth that it is shiny. However, when highly magnified, the surface of metal appears to be very bumpy. All those mountains and valleys catch and grab the mountains and valleys of any other surface that contacts the metal. This creates friction.
What determines the reactivity of an atom?	neutral electrons	reactive electrons	unstable electrons	valence electrons	Valence electrons determine the reactivity of an atom.
What is the fusing of two or more smaller nuclei to form a single, larger nucleus?	radiactive fusion	atomic fusion	likely fusion	nuclear fusion	Nuclear fusion is the fusing of two or more smaller nuclei to form a single, larger nucleus. Fusion releases even more energy than fission. Researchers are trying to find a way to use the energy from nuclear fusion to generate electricity.
What part of the plant absorbs water?	flower	leaves	stem	roots	null
What is the term for the attraction between oppositely charged atoms or ions?	magnetic bond	covalent bond	neutron bond	ionic bond	null
What are the outer planets of the solar system made of?	solids	plasma	liquids	gases	The inner planets are small and rocky, while the outer planets are large and made of gases. Why might the planets have formed into these two groups?.
Allergy symptoms can be treated with medications such as?	hormone treatments	antibiotics	channel blockers	antihistamines	Allergy symptoms can range from mild to severe. Mild symptoms might include itchy eyes, sneezing, and a runny nose. Severe symptoms can cause difficulty breathing, which may be life threatening. Keep in mind that it is the immune system and not the allergen that causes the allergy symptoms. Allergy symptoms can be treated with medications such as antihistamines. Severe allergic reactions may require an injection of the hormone epinephrine. These treatments lessen or counter the immune system’s response.
What is considered to be the most common intrusive igneous rock?	obsidian	sandstone	basalt	granite	Granite is the most common intrusive igneous rock. Pictured below are four types of intrusive rocks ( Figure below ).
Which type of carbohydrate is glucose?	sweet	compound	fluid	simple	Sugars are simple carbohydrates such as glucose, which the cells of living things use for energy.
What obstructs people from seeing the milky way at night?	coriolis effect	the Moon	myopia	light pollution	There is so much light pollution in most cities that many people have never seen the Milky Way. On a clear night away from lights, the view is of a bright white river of stars. You don't need a telescope or even binoculars to see it. The view of the Milky Way is so bright because you're looking at the stars in your own galaxy.
The north end of a compass needle points toward which of earth's magnetic poles?	west	west	south	north	Q: The north end of a compass needle points toward Earth’s north magnetic pole. The like poles of two magnets repel each other, and the opposite poles attract. So why doesn’t the north end of a compass needle point to Earth’s south magnetic pole instead?.
Deer, rabbits and mice are an example of what link between producers and other consumers?	amphibians	carnivores	mammals	herbivores	Herbivores consume producers such as plants or algae. They are a necessary link between producers and other consumers. Examples include deer, rabbits, and mice.
What is the name of the process of creating offspring from just one individual animal?	ideal reproduction	organic reproduction	sexual reproduction	asexual reproduction	No, not all animals have two parents. When necessary, some animals can be produced from just one parent. Some reptiles, such as this Komodo dragon, have only one parent. The process of creating offspring from just one individual is called asexual reproduction.
Strength, the ability of a muscle to use force during a contraction, differs from what term meaning the ability of a muscle to continue to contract over time without getting tired?	recovery	resilience	energy	endurance	Exercise improves both muscular strength and muscular endurance. Muscular strength is the ability of a muscle to use force during a contraction. Muscular endurance is the ability of a muscle to continue to contract over a long time without getting tired.
What disease-causing acellular entities containing either dna or rna replicate using the replication proteins of a host cell?	pathogens	parasites	parasitic worms	viruses	CHAPTER SUMMARY 17.1 Viruses Viruses are acellular entities that can usually only be seen with an electron microscope. Their genomes contain either DNA or RNA, and they replicate using the replication proteins of a host cell. Viruses are diverse, infecting archaea, bacteria, fungi, plants, and animals. Viruses consist of a nucleic-acid core surrounded by a protein capsid with or without an outer lipid envelope. Viral replication within a living cell always produces changes in the cell, sometimes resulting in cell death and sometimes slowly killing the infected cells. There are six basic stages in the virus replication cycle: attachment, penetration, uncoating, replication, assembly, and release. A viral infection may be productive, resulting in new virions, or nonproductive, meaning the virus remains inside the cell without producing new virions. Viruses cause a variety of diseases in humans. Many of these diseases can be prevented by the use of viral vaccines, which stimulate protective immunity against the virus without causing major disease. Viral vaccines may also be used in active viral infections, boosting the ability of the immune system to control or destroy the virus. Antiviral drugs that target enzymes and other protein products of viral genes have been developed and used with mixed success. Combinations of anti-HIV drugs have been used to effectively control the virus, extending the lifespan of infected individuals.
What type of virus is the flu caused by?	Mononucleosis	Rubella	pneumonia	influenza	Doesn't look like fun. The flu is caused by an influenza virus. And usually a slightly different virus every season.
Almost all leaves are specialized for what process?	sex	measurements	reactions	photosynthesis	null
Some inhibitor molecules bind to enzymes in a location where their binding induces a conformational change that reduces the affinity of the enzyme for its substrate. this type of inhibition is called allosteric what?	induction	secretion	mutation	inhibition	On the other hand, in noncompetitive inhibition, an inhibitor molecule binds to the enzyme in a location other than the active site, called an allosteric site, but still manages to block substrate binding to the active site. Some inhibitor molecules bind to enzymes in a location where their binding induces a conformational change that reduces the affinity of the enzyme for its substrate. This type of inhibition is called allosteric inhibition (Figure 4.9). Most allosterically regulated enzymes are made up of more than one polypeptide, meaning that they have more than one protein subunit. When an allosteric inhibitor binds to a region on an enzyme, all active sites on the protein subunits are changed slightly such that they bind their substrates with less efficiency. There are allosteric activators as well as inhibitors. Allosteric activators bind to locations on an enzyme away from the active site, inducing a conformational change that increases the affinity of the enzyme’s active site(s) for its substrate(s) (Figure 4.9).
During which process does carbon dioxide exit the cells, enter the bloodstream, travel back to the lungs, and get expired out of the body?	osmosis	peroxidation	inhalation	exhalation	The Respiratory System Take a breath in and hold it. Wait several seconds and then let it out. Humans, when they are not exerting themselves, breathe approximately 15 times per minute on average. This equates to about 900 breaths an hour or 21,600 breaths per day. With every inhalation, air fills the lungs, and with every exhalation, it rushes back out. That air is doing more than just inflating and deflating the lungs in the chest cavity. The air contains oxygen that crosses the lung tissue, enters the bloodstream, and travels to organs and tissues. There, oxygen is exchanged for carbon dioxide, which is a cellular waste material. Carbon dioxide exits the cells, enters the bloodstream, travels back to the lungs, and is expired out of the body during exhalation.
Exotic species, also known as invasive or non-native species often cause _______ when introduced to new environments.	harmony	radicalization	confusion	extinction	One of the main causes of extinction is introduction of exotic species into an environment. These exotic and new species can also be called invasive species or non-native species . These non-native species, being new to an area, may not have natural predators in the new habitat, which allows their populations to easily adapt and grow. Invasive species out-compete the native species for resources. Sometimes invasive species are so successful at living in a certain habitat that the native species go extinct ( Figure below ).
What is formed when light rays diverge behind a lens?	a projection	a hologram	a shadow	a virtual image	When light rays diverge behind a lens, a virtual image is formed. A virtual image is a manifestation of your brain (it traces the diverging rays backwards and forms an image), like the person you see “behind” a mirror’s surface when you brush your teeth (there's obviously no real light focused behind a mirror!). Since virtual images aren’t actually “anywhere,” you can’t place photographic film anywhere to capture them.
An equipotential line is a line along which the electric potential is wht?	changeable	increasing	decreasing	constant	An equipotential line is a line along which the electric potential is constant. An equipotential surface is a three-dimensional version of equipotential lines. Equipotential lines are always perpendicular to electric field lines. The process by which a conductor can be fixed at zero volts by connecting it to the earth with a good conductor is called grounding.
Keratin is an intracellular fibrous protein that gives hair, nails, and skin their hardness and this?	friction resistant properties	heat resistant properties	cold - resistant properties	water-resistant properties	The cells in all of the layers except the stratum basale are called keratinocytes. A keratinocyte is a cell that manufactures and stores the protein keratin. Keratin is an intracellular fibrous protein that gives hair, nails, and skin their hardness and water-resistant properties. The keratinocytes in the stratum corneum are dead and regularly slough away, being replaced by cells from the deeper layers (Figure 5.4).
The insect reaches full size, acquires wings, and becomes sexually mature after what final stage?	metamorphosis	pupae	larvae	molt	null
Body movements help circulate the hemolymph by periodically squeezing what?	the heart	the lungs	muscles	the sinuses	null
What is the name of the effect that causes air masses to move on a diagonal?	aurora borealis	polar effect	the headwind effect	the coriolis effect	Why do air masses move? Winds and jet streams push them along. Cold air masses tend to move toward the Equator. Warm air masses tend to move toward the poles. The Coriolis effect causes them to move on a diagonal. Many air masses move toward the northeast over the U. S. This is the same direction that global winds blow.
Peristalsis is necessary for what basic bodily function?	regeneration	reproduction	respiration	digestion	Describe peristalsis, and explain why it is necessary for digestion.
Radioactive isotopes have the same chemical properties as stable isotopes of the same element. still, how is radioactive isotope different from stable isotopes?	they absorb light	they absorb radiation	they emit magnetism	they emit radiation	Radioactive isotopes have the same chemical properties as stable isotopes of the same element, but they emit radiation, which can be detected. If we replace one (or more) atom(s) with radioisotope(s) in a compound, we can track them by monitoring their radioactive emissions. This type of compound is called a radioactive tracer (or radioactive label). Radioisotopes are used to follow the paths of biochemical reactions or to determine how a substance is distributed within an organism. Radioactive tracers are also used in many medical applications, including both diagnosis and treatment. They are used to measure engine wear, analyze the geological formation around oil wells, and much more. Radioisotopes have revolutionized medical practice (see Appendix M), where they are used extensively. Over 10 million nuclear medicine procedures and more than 100 million nuclear medicine tests are performed annually in the United States. Four typical examples of radioactive tracers used in medicine are technetium-99 ( 99 , thallium-201 43 Tc) , iodine-131 ( 131 , and sodium-24 ( 24 . Damaged tissues in the heart, liver, and lungs absorb certain ( 201 81 Tl) 11 Na) 53 I) compounds of technetium-99 preferentially. After it is injected, the location of the technetium compound, and hence the damaged tissue, can be determined by detecting the γ rays emitted by the Tc-99 isotope. Thallium-201 (Figure 21.24) becomes concentrated in healthy heart tissue, so the two isotopes, Tc-99 and Tl-201, are used together to study heart tissue. Iodine-131 concentrates in the thyroid gland, the liver, and some parts of the brain. It can therefore be used to monitor goiter and treat thyroid conditions, such as Grave’s disease, as well as liver and brain tumors. Salt solutions containing compounds of sodium-24 are injected into the bloodstream to help locate obstructions to the flow of blood.
What can be described in terms of physical properties and chemical properties as well as its defining states?	mass	energy	empty space	matter	Matter can be described in terms of physical properties and chemical properties.
Wetlands are extremely important as an ecosystem and as a filter for what?	storms	wind	clouds	pollutants	Wetlands are extremely important as an ecosystem and as a filter for pollutants.
Amphibians generally rely heavily on their moist skin for what with the environment?	sensory perception	cooling	competition	gas exchange	null
A change in species over time is known as?	divergence	variation	generation	evolution	Evolution is a change in species over time.
What type of event nearly always occurs at plate boundaries?	eruption	hurricane	tsunami	earthquake	Scientists are not able to predict earthquakes. Since nearly all earthquakes take place at plate boundaries, scientists can predict where an earthquake will occur ( Figure below ). This information helps communities to prepare for an earthquake. For example, they can require that structures are built to be earthquake safe.
Each f atom has one bonding pair and three lone pairs of what?	protons	ions	megatrons	electrons	There are two different types of electrons in the fluorine diatomic molecule. The bonding electron pair makes the covalent bond. Each F atom has three other pairs of electrons that do not participate in the bonding; they are called lone electron pairs. Each F atom has one bonding pair and three lone pairs of electrons. Covalent bonds can be made between different elements as well. One example is HF. Each atom starts out with an odd number of electrons in its valence shell:.
The embryo sac consists of only a few cells, one of which is the what?	sperm	mitochondria	dna	egg	null
What type of organisms collect the energy from the sun and turn it into organic compounds?	organelles	microbes	heterotrophs	autotrophs	If a plant gets hungry, it cannot walk to a local restaurant and buy a slice of pizza. So, how does a plant get the food it needs to survive? Plants are producers , which means they are able to make, or produce, their own food. They also produce the "food" for other organisms. Plants are also autotrophs. Autotrophs are the organisms that collect the energy from the sun and turn it into organic compounds. Using the energy from the sun, they produce complex organic compounds from simple inorganic molecules. So once again, how does a plant get the food it needs to survive?.
Force is a vector because it has what two things?	size and depth	matter and direction	space and time	size and direction	Force is a vector because it has both size and direction. Like other vectors, it can be represented by an arrow.
What type of rock makes up most of the earth?	Sedimentary	tuberous	Metamorphic	igneous	Most of the Earth is made of igneous rock. The entire mantle is igneous rock, as are some areas of the crust. One of the most common igneous rocks is granite ( Figure below ). Many mountain ranges are made of granite. People use granite for countertops, buildings, monuments and statues. Pumice is also an igneous rock. Perhaps you have used a pumice stone to smooth your skin. Pumice stones are put into giant washing machines with new jeans and tumbled around. The result is stone-washed jeans!.
The seven bones of the ankle are called the what?	termals	ankular	femurs	tarsals	The tarsals are the seven bones of the ankle. The ankle transmits the weight of the body from the tibia and the fibula to the foot. The metatarsals are the five bones of the foot. The phalanges are the 14 bones of the toes. Each toe consists of three phalanges, except for the big toe that has only two (Figure 38.15). Variations exist in other species; for example, the horse’s metacarpals and metatarsals are oriented vertically and do not make contact with the substrate.
What is the name for the amount of energy that is required in order to begin a chemical reaction?	conduction	function	catalytic	activation	Although the overall process involves a release of energy (the products are lower energy than the reactants), a certain initial amount of energy needs to be present before the reaction can occur. The amount of energy required to get over the "hump" in the reaction diagram is referred to as the activation energy of the reaction. At the top of the peak, the reactants form what is known as an activated complex. The activated complex is the highest energy state that must be achieved in order for reactants to convert into products.
Presence or absence of what feature distinguishes vertebrates from invertebrates?	heart	hair	scales	backbone	Animals are often identified as being either invertebrates or vertebrates. These are terms based on the skeletons of the animals. Vertebrates have a backbone made of bone or cartilage ( cartilage is a flexible supportive tissue. You have cartilage in your ear lobes. ). Invertebrates , on the other hand, have no backbone ( Figure below ). Invertebrates live just about anywhere. There are so many invertebrates on this planet that it is impossible to count them all. There are probably billions of billions of invertebrates. They come in many shapes and sizes, live practically anywhere and provide many services that are vital for the survival of other organisms, including us. They have been observed in the upper reaches of the atmosphere, in the driest of the deserts and in the canopies of the wettest rainforests. They can even be found in the frozen Antarctic or on the deepest parts of the ocean floor.
All the bones of the skull, except for the mandible, are joined to each other by a fibrous joint called what?	aperture	stucco	blade	suture	Suture All the bones of the skull, except for the mandible, are joined to each other by a fibrous joint called a suture. The fibrous connective tissue found at a suture (“to bind or sew”) strongly unites the adjacent skull bones and thus helps to protect the brain and form the face. In adults, the skull bones are closely opposed and fibrous connective tissue fills the narrow gap between the bones. The suture is frequently convoluted, forming a tight union that prevents most movement between the bones. (See Figure 9.5a. ) Thus, skull sutures are functionally classified as a synarthrosis, although some sutures may allow for slight movements between the cranial bones. In newborns and infants, the areas of connective tissue between the bones are much wider, especially in those areas on the top and sides of the skull that will become the sagittal, coronal, squamous, and lambdoid sutures. These broad areas of connective tissue are called fontanelles (Figure 9.6). During birth, the fontanelles provide flexibility to the skull, allowing the bones to push closer together or to overlap slightly, thus aiding movement of the infant’s head through the birth canal. After birth, these expanded regions of connective tissue allow for rapid growth of the skull and enlargement of the brain. The fontanelles greatly decrease in width during the first year after birth as the skull bones enlarge. When the connective tissue between the adjacent bones is reduced to a narrow layer, these fibrous joints are now called sutures. At some sutures, the connective tissue will ossify and be converted into bone, causing the adjacent bones to fuse to each other. This fusion between bones is called a synostosis (“joined by bone”). Examples of synostosis fusions between cranial bones are found both early and late in life. At the time of birth, the frontal and maxillary bones consist of right and left halves joined together by sutures, which disappear by the eighth year as the halves fuse together to form a single bone. Late in life, the sagittal, coronal, and lambdoid sutures of the skull will begin to ossify and fuse, causing the suture line to gradually disappear.
What do we use to keep track of electric potential energy?	wattage	temperature	amperage	voltage	Like gravity, the electric force can do work and has a potential energy associated with it. But like we use fields to keep track of electromagnetic forces, we use electric potential , or voltage to keep track of electric potential energy. So instead of looking for the potential energy of specific objects, we define it in terms of properties of the space where the objects are.
Ozone loss increases the amount of what high-energy radiation that strikes earth?	gamma rays	infrared	microwaves	ultraviolet	Ozone loss increases the amount of high-energy ultraviolet radiation that strikes Earth. This can cause ecological and health problems.
What are two simple and common types of capacitor connections?	flux and parallel	series and ionic	appearance and parallel	series and parallel	19.6 Capacitors in Series and Parallel Several capacitors may be connected together in a variety of applications. Multiple connections of capacitors act like a single equivalent capacitor. The total capacitance of this equivalent single capacitor depends both on the individual capacitors and how they are connected. There are two simple and common types of connections, called series and parallel, for which we can easily calculate the total capacitance. Certain more complicated connections can also be related to combinations of series and parallel.
What is the last step in scientific investigation?	migration of results	data management	document of results	communication of results	The last step in a scientific investigation is the communication of results with others.
Nematodes have an alimentary canal, but lack what?	nervous system	lymphatic system	metabolism system	circulatory system	null
What instrument is used to make objects in space appear closer?	mirror	microscope	GPS	telescope	Telescopes made objects in space seem closer. But they didn't make it any easier to visit them. Human space flight required something entirely different: rockets.
Which law predicts increasing entropy based on living systems?	kelper's	kinetic	planetary	thermodynamic	null
An amine is an organic compound that can be considered to be a derivative of what?	calcium	nitrogen	lead	ammonia	An amine is an organic compound that can be considered to be a derivative of ammonia (NH 3 ). The general structure of an amine can be abbreviated as R−NH 2 , where R is a carbon chain. However, similar to alcohols, amines can be primary, secondary, or tertiary.
The hormones epinephrine and norepinephrine are associated with what rhyming mechanism?	bright - or - flight	light - or- flight	right - or - flight	fight-or-flight	Epinephrine and Norepinephrine The catecholamines, epinephrine and NE, secreted by the adrenal medulla form one component of the extended fight-orflight mechanism. The other component is sympathetic stimulation. Epinephrine and NE have similar effects: binding to the beta-1 receptors, and opening sodium and calcium ion chemical- or ligand-gated channels. The rate of depolarization is increased by this additional influx of positively charged ions, so the threshold is reached more quickly and the period of repolarization is shortened. However, massive releases of these hormones coupled with sympathetic stimulation may actually lead to arrhythmias. There is no parasympathetic stimulation to the adrenal medulla.
Matter is composed of exceedingly small particles called what?	ions	crystals	cells	atoms	Atomic Theory through the Nineteenth Century The earliest recorded discussion of the basic structure of matter comes from ancient Greek philosophers, the scientists of their day. In the fifth century BC, Leucippus and Democritus argued that all matter was composed of small, finite particles that they called atomos, a term derived from the Greek word for “indivisible. ” They thought of atoms as moving particles that differed in shape and size, and which could join together. Later, Aristotle and others came to the conclusion that matter consisted of various combinations of the four “elements”—fire, earth, air, and water—and could be infinitely divided. Interestingly, these philosophers thought about atoms and “elements” as philosophical concepts, but apparently never considered performing experiments to test their ideas. The Aristotelian view of the composition of matter held sway for over two thousand years, until English schoolteacher John Dalton helped to revolutionize chemistry with his hypothesis that the behavior of matter could be explained using an atomic theory. First published in 1807, many of Dalton’s hypotheses about the microscopic features of matter are still valid in modern atomic theory. Here are the postulates of Dalton’s atomic theory. Matter is composed of exceedingly small particles called atoms. An atom is the smallest unit of an element.
Gases have no definite shape or what?	smell	growth	mass	volume	Gases have no definite shape or volume.
Elements have orbitals that are filled with what?	photons	particles	ions	electrons	enters a d orbital. The valence electrons (those added after the last noble gas configuration) in these elements include the ns and (n – 1) d electrons. The official IUPAC definition of transition elements specifies those with partially filled d orbitals. Thus, the elements with completely filled orbitals (Zn, Cd, Hg, as well as Cu, Ag, and Au in Figure 6.30) are not technically transition elements. However, the term is frequently used to refer to the entire d block (colored yellow in Figure 6.30), and we will adopt this usage in this textbook. Inner transition elements are metallic elements in which the last electron added occupies an f orbital. They.
Most protein antigens require signals from helper t cells (th2) to proceed to make what?	antioxidant	protein	bacterium	antibody	B Cell Differentiation and Activation B cells differentiate in the bone marrow. During the process of maturation, up to 100 trillion different clones of B cells are generated, which is similar to the diversity of antigen receptors seen in T cells. B cell differentiation and the development of tolerance are not quite as well understood as it is in T cells. Central tolerance is the destruction or inactivation of B cells that recognize self-antigens in the bone marrow, and its role is critical and well established. In the process of clonal deletion, immature B cells that bind strongly to self-antigens expressed on tissues are signaled to commit suicide by apoptosis, removing them from the population. In the process of clonal anergy, however, B cells exposed to soluble antigen in the bone marrow are not physically deleted, but become unable to function. Another mechanism called peripheral tolerance is a direct result of T cell tolerance. In peripheral tolerance, functional, mature B cells leave the bone marrow but have yet to be exposed to self-antigen. Most protein antigens require signals from helper T cells (Th2) to proceed to make antibody. When a B cell binds to a self-antigen but receives no signals from a nearby Th2 cell to produce antibody, the cell is signaled to undergo apoptosis and is destroyed. This is yet another example of the control that T cells have over the adaptive immune response. After B cells are activated by their binding to antigen, they differentiate into plasma cells. Plasma cells often leave the secondary lymphoid organs, where the response is generated, and migrate back to the bone marrow, where the whole differentiation process started. After secreting antibodies for a specific period, they die, as most of their energy is devoted to making antibodies and not to maintaining themselves. Thus, plasma cells are said to be terminally differentiated. The final B cell of interest is the memory B cell, which results from the clonal expansion of an activated B cell. Memory B cells function in a way similar to memory T cells. They lead to a stronger and faster secondary response when compared to the primary response, as illustrated below.
What is caused by the buildup of stress in the rocks?	debris tilting	ground fall	ground dropping	ground tilting	There are other possible signs before an earthquake. The ground may tilt. Ground tilting is caused by the buildup of stress in the rocks. This may happen before a large earthquake, but it doesn't always. Water levels in wells may fluctuate. This is because water may move into or out of fractures before an earthquake. This is also an uncertain way to predict an earthquake. The difference in arrival times of P-waves and S-waves may decrease just before an earthquake occurs.
Forty percent of your body mass is made up of what?	cardiac muscle	skin	blood	skeletal muscle	Skeletal muscle is attached to bones and its contraction makes possible locomotion, facial expressions, posture, and other voluntary movements of the body. Forty percent of your body mass is made up of skeletal muscle. Skeletal muscles generate heat as a byproduct of their contraction and thus participate in thermal homeostasis. Shivering is an involuntary contraction of skeletal muscles in response to perceived lower than normal body temperature. The muscle cell, or myocyte,.
Water is composed of which two elements?	carbon and dioxide	oxygen and nitrogen	hydrogen and nitrogen	hydrogen and oxygen	Water is a binary compound composed of hydrogen and oxygen. The hydrogen and oxygen gases produced in the reaction are both diatomic molecules.
A polar covalent bond is a covalent bond between different atoms that attract the shared electrons by different amounts and cause an imbalance of what ?	neutron distribution	proton distribution	ions distribution	electron distribution	EXAMPLE 13 Describe the bonding in the nitrite ion in terms of a combination of hybrid atomic orbitals and molecular orbitals. Lewis dot structures and the VSEPR model predict that the NO2− ion is bent. Given: chemical species and molecular geometry Asked for: bonding description using hybrid atomic orbitals and molecular orbitals Strategy: A Calculate the number of valence electrons in NO2−. From the structure, predict the type of atomic orbital hybridization in the ion. B Predict the number and type of molecular orbitals that form during bonding. Use valence electrons to fill these orbitals and then calculate the number of electrons that remain. C If there are unhybridized orbitals, place the remaining electrons in these orbitals in order of increasing energy. Calculate the bond order and describe the bonding. Solution: A The lone pair of electrons on nitrogen and a bent structure suggest that the bonding in NO 2− is similar to the bonding in ozone. This conclusion is supported by the fact that nitrite also contains 18 valence electrons (5 from N and 6 from each O, plus 1 for the −1 charge). The bent structure implies that the nitrogen is sp2 hybridized. B If we assume that the oxygen atoms are sp2 hybridized as well, then we can use twosp2 hybrid orbitals on each oxygen and one sp2 hybrid orbital on nitrogen to accommodate the five lone pairs of electrons. Two sp2 hybrid orbitals on nitrogen form σ bonds with the remaining sp2 hybrid orbital on each oxygen.
What two things are excess proteins converted into?	fructose or triglycerides	sucrose or triglycerides	glucose or sucrose	glucose or triglycerides	serve as a metabolic fuel source. Proteins are not stored for later use, so excess proteins must be converted into glucose or triglycerides, and used to supply energy or build energy reserves. Although the body can synthesize proteins from amino acids, food is an important source of those amino acids, especially because humans cannot synthesize all of the 20 amino acids used to build proteins. The digestion of proteins begins in the stomach. When protein-rich foods enter the stomach, they are greeted by a mixture of the enzyme pepsin and hydrochloric acid (HCl; 0.5 percent). The latter produces an environmental pH of 1.5–3.5 that denatures proteins within food. Pepsin cuts proteins into smaller polypeptides and their constituent amino acids. When the food-gastric juice mixture (chyme) enters the small intestine, the pancreas releases sodium bicarbonate to neutralize the HCl. This helps to protect the lining of the intestine. The small intestine also releases digestive hormones, including secretin and CCK, which stimulate digestive processes to break down the proteins further. Secretin also stimulates the pancreas to release sodium bicarbonate. The pancreas releases most of the digestive enzymes, including the proteases trypsin, chymotrypsin, and elastase, which aid protein digestion. Together, all of these enzymes break complex proteins into smaller individual amino acids (Figure 24.17), which are then transported across the intestinal mucosa to be used to create new proteins, or to be converted into fats or acetyl CoA and used in the Krebs cycle.
What is an individual living creature called?	protist	amino	species	organism	An individual living creature is called an organism . There are many characteristics that living organisms share. They all:.
What kind of a reaction if peptide bond formation?	recharge synthesis reaction	molten synthesis reaction	reversed synthesis reaction	dehydration synthesis reaction	Figure 3.24 Peptide bond formation is a dehydration synthesis reaction. The carboxyl group of one amino acid is linked to the amino group of the incoming amino acid. In the process, a molecule of water is released.
What are the elements of group 17 (fluorine, chlorine, bromine, iodine, and astatine) called?	antioxidants	metals	liquids	halogens	The elements of Group 17 (fluorine, chlorine, bromine, iodine, and astatine) are called the halogens . The halogens all have the general electron configuration n s 2 n p 5 , giving them seven valence electrons. They are one electron short of having full outer s and p sublevels, which makes them very reactive. They undergo especially vigorous reactions with the reactive alkali metals. In their pure elemental forms, chlorine and fluorine are gases at room temperature, bromine is a dark orange liquid, and iodine is a dark purple-gray solid. Astatine is so rare that its properties are mostly unknown.
What is the term for growing towards gravity?	pollenation	surviving	spirogyra	geotropism	As you read earlier in this chapter, plant roots always grow downward because specialized cells in root caps detect and respond to gravity. This is an example of a tropism. A tropism is a turning toward or away from a stimulus in the environment. Growing toward gravity is called geotropism. Plants also exhibit phototropism, or growing toward a light source. This response is controlled by a plant growth hormone called auxin. As shown in Figure below , auxin stimulates cells on the dark side of a plant to grow longer. This causes the plant to bend toward the light.
What does our solar system orbit over the course of hundreds of millions of years?	retrograde center	volcanic center	a black hole	galactic center	Our solar system orbits the center of the galaxy as the galaxy spins. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago.
What do inherited immunodeficiencies arise from?	stem cells	Allopatric speciation	viral infections	gene mutations	Immunodeficiencies As you have seen, the immune system is quite complex. It has many pathways using many cell types and signals. Because it is so complex, there are many ways for it to go wrong. Inherited immunodeficiencies arise from gene mutations that affect specific components of the immune response. There are also acquired immunodeficiencies with potentially devastating effects on the immune system, such as HIV.
What kinds of winds can be found in belts that span the entire circumference of the earth?	Periodic winds	Trade winds	Local Winds	global winds	Global winds are winds that occur in belts that go all around the planet ( Figure below ). Like local winds, global winds are caused by unequal heating of the atmosphere.
Touching, coughing, or sneezing are examples of directly spreading what microorganisms, which cause diseases like tetanus?	algae	pollen	viruses	bacteria	You have ten times as many bacteria as human cells in your body. Most of these bacteria are harmless. However, bacteria can also cause disease. Examples of bacterial diseases include tetanus, syphilis, and food poisoning. Bacteria may spread directly from one person to another. For example, they can spread through touching, coughing, or sneezing. They may also spread via food, water, or objects.
Which blood pressure is highest when the heart contracts during ventricular systole?	diastolic	systolic	resting rate	arterial	null
All the members of a species that live in the same area form a what?	habitat	biome	biosphere	population	All the members of a species that live in the same area form a population . Many different species live together in an ecosystem. All their populations make up a community . What populations live together in the grassland pictured below ( Figure above )?.
New species may be created by natural selection and one other way. what is the other way?	squalling selection	fake selection	obvious selection	artifical selection	Speciation, the creation of a new species, can happen through natural selection or artificial selection.
What type of illness is influenza?	cardiac illness	mental illness	stomach illness	respiratory illness	Influenza, or flu, is a contagious respiratory illness caused by influenza viruses. Influenza spreads around the world in seasonal epidemics. An epidemic is an outbreak of a disease within a population of people during a specific time. Every year in the United States, about 200,000 people are hospitalized and 36,000 people die from the flu. Flu pandemics can kill millions of people. A pandemic is an epidemic that spreads through human populations across a large region (for example a continent), or even worldwide. Three influenza pandemics occurred in the 20th century and killed tens of millions of people, with each of these pandemics being caused by the appearance of a new strain of the virus. Most influenza strains can be inactivated easily by disinfectants and detergents.
In which process do paired chromosomes normally separate from each other?	diffusion	mutations	gametes	meiosis	In the process of meiosis, paired chromosomes normally separate from each other. They end up in different gametes. Sometimes, however, errors occur. The paired chromosomes fail to separate. When this happens, some gametes get an extra copy of a chromosome. Other gametes are missing a chromosome. If one of these gametes is fertilized and survives, a chromosomal disorder results. You can see examples of such disorders in Table below.
About how many years ago did our solar system begin?	60 billion	3 billion	10 billion	5 billion years	Our solar system began about 5 billion years ago. The Sun, planets and other solar system objects all formed at about the same time.
What is the energy change called when a neutral atom gains an electron?	nuclear fission	fusion gain	mass affinity	electron affinity	The energy change that occurs when a neutral atom gains an electron is called its electron affinity . When energy is released in a chemical reaction or process, that energy is expressed as a negative number. The figure below shows electron affinities in kJ/mole for the representative elements. Electron affinities are measured on atoms in the gaseous state and are very difficult to measure accurately.
What kind of interference characteristics does matter have compared to any wave?	when	DIfferent	one	same	29.7 Probability: The Heisenberg Uncertainty Principle • Matter is found to have the same interference characteristics as any other wave. • There is now a probability distribution for the location of a particle rather than a definite position. • Another consequence of the wave character of all particles is the Heisenberg uncertainty principle, which limits the precision with which certain physical quantities can be known simultaneously. For position and momentum, the uncertainty principle is.
Which can cause serious metabolic disorders, too little or too much thyroid hormone in the blood?	too little only	neither	too much only	both	null
How many colors of light can the human eye detect?	six	infinite	nine	three	The human eye can detect only three colors of light. What three colors are they? How can we perceive other colors of light?.
The length of a linear accelerator and the size of the d-shaped electrodes in a cyclotron severely limit the kinetic energy that particles can attain in these devices. these limitations can be overcome by using one of these?	magnet	plastic	metal	synchrotron	To achieve the same outcome in less space, a particle accelerator called a cyclotronforces the charged particles to travel in a circular path rather than a linear one. The particles are injected into the center of a ring and accelerated by rapidly alternating the polarity of two large D-shaped electrodes above and below the ring, which accelerates the particles outward along a spiral path toward the target. The length of a linear accelerator and the size of the D-shaped electrodes in a cyclotron severely limit the kinetic energy that particles can attain in these devices. These limitations can be overcome by using a synchrotron, a hybrid of the two designs. A synchrotron contains an evacuated tube similar to that of a linear accelerator, but the tube is circular and can be more than a mile in diameter (Figure 20.10 "A Synchrotron"). Charged particles are accelerated around the circle by a series of magnets whose polarities rapidly alternate.
The mammalian sense of touch also relies on mechanoreceptors that are the dendrites of sensory?	electrons	ions	nerves	neurons	null
What is the largest known animal?	the white shark	the elephant	the giraffe	the blue whale	Living things in the oceans are called marine organisms . They range from tiny bacteria to the largest known animal, the blue whale. All are adapted for life in salt water. Most are adapted for extreme pressures.
Polymers can disassemble by the reverse process called what?	electrolysis	mitosis	dehydration	hydrolysis	null
Purple loosestrife is a european wildflower that was introduced to which continent in the 1800's?	australia	south america	asia	north america	Purple loosestrife is a European wildflower that was introduced to North America in the early 1800s. It soon spread to take over wetland habitats throughout the U. S. and Canada. Purple loosestrife replaces native wetland plants and threatens native wildlife by eliminating natural foods and cover. It also blocks irrigation systems.
The male gametangium that produces sperm is also called what?	trichina	xerophyte	echinacea	antheridium	Gametangia in the Seedless Plants Gametangia (singular, gametangium) are structures on the gametophytes of seedless plants in which gametes are produced by mitosis. The male gametangium, the antheridium, releases sperm. Many seedless plants produce sperm equipped with flagella that enable them to swim in a moist environment to the archegonia, the female gametangium. The embryo develops inside the archegonium as the sporophyte. Apical Meristems The shoots and roots of plants increase in length through rapid cell division within a tissue called the apical meristem (Figure 14.5). The apical meristem is a cap of cells at the shoot tip or root tip made of undifferentiated cells that continue to proliferate throughout the life of the plant. Meristematic cells give rise to all the specialized tissues of the plant. Elongation of the shoots and roots allows a plant to access additional space and resources: light in the case of the shoot, and water and minerals in the case of roots. A separate meristem, called the lateral meristem, produces cells that increase the diameter of stems and tree trunks. Apical meristems are an adaptation to allow vascular plants to grow in directions essential to their survival: upward to greater availability of sunlight, and downward into the soil to obtain water and essential minerals.
What part is written first when naming an ionic compound?	carbonate	anion	Atom	cation	Ionic compounds are named by writing the name of the cation followed by the name of the anion.
How does adding salt to water affect the boiling point?	maintains	no difference	reduces	increases	Salt is often added to boiling water when preparing spaghetti or other pasta. One reason is to add flavor to the food. Some people believe that the addition of salt increases the boiling point of the water. Technically, they are correct, but the increase is rather small. You would need to add over 100 grams of NaCl to a liter of water to increase the boiling point a couple of degrees, which is just not healthy.
What mineral is used in jewelry because of its striking greenish-blue color?	lime	aqua	glass	turquoise	Diamonds have many valuable properties. Diamonds are extremely hard and are used for industrial purposes. The most valuable diamonds are large, well-shaped and sparkly. Turquoise is another mineral that is used in jewelry because of its striking greenish-blue color. Many minerals have interesting appearances. Specific terms are used to describe the appearance of minerals.
Ionic bonds are formed between which ions?	with the same charges	with multiple charges	with random charges	with opposite charges	Ionic bonds are formed between ions with opposite charges. For instance, positively charged sodium ions and negatively charged chloride ions bond together to make crystals of sodium chloride, or table salt, creating a crystalline molecule with zero net charge. Certain salts are referred to in physiology as electrolytes (including sodium, potassium, and calcium), ions necessary for nerve impulse conduction, muscle contractions and water balance. Many sports drinks and dietary supplements provide these ions to replace those lost from the body via sweating during exercise.
What causes most ocean waves?	tides	Gravity	rains	winds	Most ocean waves are caused by winds. A wave is the transfer of energy through matter. A wave that travels across miles of ocean is traveling energy, not water. Ocean waves transfer energy from wind through water. The energy of a wave may travel for thousands of miles. The water itself moves very little. Figure below shows how water molecules move when a wave goes by.
What work by lowering the activation energy of reactions and are needed to speed up chemical reactions in organisms?	molecules	compounds	Proteins	enzymes	Enzymes are needed to speed up chemical reactions in organisms. They work by lowering the activation energy of reactions.
Exon skipping is an example of what type of splicing?	comprehensive	inclusive	proactive	alternative	One example of alternative splicing is with exon skipping. The D. melanogaster (fruit fly) doublesex (dsx) gene is involved in the fly's determination system. Pre-mRNAs from this gene contain 6 eons, numbered 1-6. In males, exons 1,2,3,5,and 6 are spliced together to form the mRNA, which encodes a transcriptional regulatory protein required for male development. In females, exons 1, 2, 3, and 4 are joined, and a polyadenylation signal in exon 4 causes cleavage of the mRNA at that point. The resulting mRNA is a transcriptional regulatory protein required for female development.
What is the term for the distance between any two corresponding points on adjacent waves?	tessellation	osscilation	bandwidth	wavelength	A wave cycle consists of one complete wave – starting at the zero point, going up to a wave crest , going back down to a wave trough , and back to the zero point again. The wavelength of a wave is the distance between any two corresponding points on adjacent waves. It is easiest to visualize the wavelength of a wave as the distance from one wave crest to the next. In an equation, wavelength is represented by the Greek letter lambda . Depending on the type of wave, wavelength can be measured in meters, centimeters, or nanometers (1 m = 10 9 nm). The frequency , represented by the Greek letter nu , is the number of waves that pass a certain point in a specified amount of time. Typically, frequency is measured in units of cycles per second or waves per second. One wave per second is also called a Hertz (Hz) and in SI units is a reciprocal second (s -1 ).
Typically, what feature of an angiosperm has four main parts known as the calyx, corolla, androecium, and gynoecium?	glass	leaves	stem	flower	Sexual Reproduction in Angiosperms The lifecycle of angiosperms follows the alternation of generations explained previously. The haploid gametophyte alternates with the diploid sporophyte during the sexual reproduction process of angiosperms. Flowers contain the plant’s reproductive structures. Flower Structure A typical flower has four main parts—or whorls—known as the calyx, corolla, androecium, and gynoecium (Figure 32.3). The outermost whorl of the flower has green, leafy structures known as sepals. The sepals, collectively called the calyx, help to protect the unopened bud. The second whorl is comprised of petals—usually, brightly colored—collectively called the corolla. The number of sepals and petals varies depending on whether the plant is a monocot or dicot. In monocots, petals usually number three or multiples of three; in dicots, the number of petals is four or five, or multiples of four and five. Together, the calyx and corolla are known as the perianth. The third whorl contains the male reproductive structures and is known as the androecium. The androecium has stamens with anthers that contain the microsporangia. The innermost group of structures in the flower is the gynoecium, or the female reproductive component(s). The carpel is the individual unit of the gynoecium and has a stigma, style, and ovary. A flower may have one or multiple carpels.
8each cell-surface receptor has three main components: an external ligand-binding domain, a hydrophobic membrane spanning region, and a(n) what domain inside the cell?	isolated	inocent	molecular	intracellular	Cell-Surface Receptors Cell-surface receptors, also known as transmembrane receptors, are cell surface, membrane-anchored (integral) proteins that bind to external ligand molecules. This type of receptor spans the plasma membrane and performs signal transduction, in which an extracellular signal is converted into an intercellular signal. Ligands that interact with cell-surface receptors do not have to enter the cell that they affect. Cell-surface receptors are also called cell-specific proteins or markers because they are specific to individual cell types. Because cell-surface receptor proteins are fundamental to normal cell functioning, it should come as no surprise that a malfunction in any one of these proteins could have severe consequences. Errors in the protein structures of certain receptor molecules have been shown to play a role in hypertension (high blood pressure), asthma, heart disease, and cancer. Each cell-surface receptor has three main components: an external ligand-binding domain, a hydrophobic membranespanning region, and an intracellular domain inside the cell. The ligand-binding domain is also called the extracellular domain. The size and extent of each of these domains vary widely, depending on the type of receptor.
Special cell in the epidermis of the skin that produces the brown pigment called what?	melatonin	cytoplasm	selenium	melanin	special cell in the epidermis of the skin that produces the brown pigment called melanin.
What are the most abundant source of energy found in most foods?	vitamins	fats	proteins	carbohydrates	Carbohydrates are the most abundant source of energy found in most foods. The simplest carbohydrates, also called simple sugars, are plentiful in fruits. A monosaccharide is a carbohydrate consisting of one sugar unit. Common examples of simple sugars or monosaccharides are glucose and fructose. Both of these monosaccharides are referred to as hexoses since they have six carbons. Glucose is abundant in many plant sources and makes up sweetners such as corn sugar or grape sugar. Fructose occurs in a great many fruits and is also found in honey. These sugars are structural isomers of one another, with the difference being that glucose contains an aldehyde functional group whereas fructose contains a ketone functional group.
What is considered to not be a form of precipitation?	snow	rain	condensation	fog	null
Both the initiation and inhibition of cell division are triggered by events external to the cell when it is about to begin which process?	extraction	mutation	isolation	replication	Regulation of the Cell Cycle by External Events Both the initiation and inhibition of cell division are triggered by events external to the cell when it is about to begin the replication process. An event may be as simple as the death of a nearby cell or as sweeping as the release of growthpromoting hormones, such as human growth hormone (HGH). A lack of HGH can inhibit cell division, resulting in dwarfism, whereas too much HGH can result in gigantism. Crowding of cells can also inhibit cell division. Another factor that can initiate cell division is the size of the cell; as a cell grows, it becomes inefficient due to its decreasing surface-tovolume ratio. The solution to this problem is to divide. Whatever the source of the message, the cell receives the signal, and a series of events within the cell allows it to proceed into interphase. Moving forward from this initiation point, every parameter required during each cell cycle phase must be met or the cycle cannot progress.
The binding of an antigen receptor to an epitope initiates events that activate the?	monocyte	endothelial	dendritic	lymphocyte	null

What is the name of matter that mechanical wave energy can only travel through?

weight

form

solid

medium

The energy of a mechanical wave can travel only through matter. This matter is called the medium ( plural , media). The medium in Figure above is a liquid — the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. It’s important to note that particles of matter in the medium don’t actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and-forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on.

What is able to occur because no surface is perfectly smooth?

temperature

mass

tension

friction

Friction occurs because no surface is perfectly smooth. Even surfaces that look smooth to the unaided eye appear rough or bumpy when viewed under a microscope. Look at the metal surfaces in Figure below . The metal foil is so smooth that it is shiny. However, when highly magnified, the surface of metal appears to be very bumpy. All those mountains and valleys catch and grab the mountains and valleys of any other surface that contacts the metal. This creates friction.

What determines the reactivity of an atom?

neutral electrons

reactive electrons

unstable electrons

valence electrons

Valence electrons determine the reactivity of an atom.

What is the fusing of two or more smaller nuclei to form a single, larger nucleus?

radiactive fusion

atomic fusion

likely fusion

nuclear fusion

Nuclear fusion is the fusing of two or more smaller nuclei to form a single, larger nucleus. Fusion releases even more energy than fission. Researchers are trying to find a way to use the energy from nuclear fusion to generate electricity.

What part of the plant absorbs water?

flower

leaves

stem

roots

null

What is the term for the attraction between oppositely charged atoms or ions?

magnetic bond

covalent bond

neutron bond

ionic bond

null

What are the outer planets of the solar system made of?

solids

plasma

liquids

gases

The inner planets are small and rocky, while the outer planets are large and made of gases. Why might the planets have formed into these two groups?.

Allergy symptoms can be treated with medications such as?

hormone treatments

antibiotics

channel blockers

antihistamines

Allergy symptoms can range from mild to severe. Mild symptoms might include itchy eyes, sneezing, and a runny nose. Severe symptoms can cause difficulty breathing, which may be life threatening. Keep in mind that it is the immune system and not the allergen that causes the allergy symptoms. Allergy symptoms can be treated with medications such as antihistamines. Severe allergic reactions may require an injection of the hormone epinephrine. These treatments lessen or counter the immune system’s response.

What is considered to be the most common intrusive igneous rock?

obsidian

sandstone

basalt

granite

Granite is the most common intrusive igneous rock. Pictured below are four types of intrusive rocks ( Figure below ).

Which type of carbohydrate is glucose?

sweet

compound

fluid

simple

Sugars are simple carbohydrates such as glucose, which the cells of living things use for energy.

What obstructs people from seeing the milky way at night?

coriolis effect

the Moon

myopia

light pollution

There is so much light pollution in most cities that many people have never seen the Milky Way. On a clear night away from lights, the view is of a bright white river of stars. You don't need a telescope or even binoculars to see it. The view of the Milky Way is so bright because you're looking at the stars in your own galaxy.

The north end of a compass needle points toward which of earth's magnetic poles?

west

south

north

Q: The north end of a compass needle points toward Earth’s north magnetic pole. The like poles of two magnets repel each other, and the opposite poles attract. So why doesn’t the north end of a compass needle point to Earth’s south magnetic pole instead?.

Deer, rabbits and mice are an example of what link between producers and other consumers?

amphibians

carnivores

mammals

herbivores

Herbivores consume producers such as plants or algae. They are a necessary link between producers and other consumers. Examples include deer, rabbits, and mice.

What is the name of the process of creating offspring from just one individual animal?

ideal reproduction

organic reproduction

sexual reproduction

asexual reproduction

No, not all animals have two parents. When necessary, some animals can be produced from just one parent. Some reptiles, such as this Komodo dragon, have only one parent. The process of creating offspring from just one individual is called asexual reproduction.

Strength, the ability of a muscle to use force during a contraction, differs from what term meaning the ability of a muscle to continue to contract over time without getting tired?

recovery

resilience

energy

endurance

Exercise improves both muscular strength and muscular endurance. Muscular strength is the ability of a muscle to use force during a contraction. Muscular endurance is the ability of a muscle to continue to contract over a long time without getting tired.

What disease-causing acellular entities containing either dna or rna replicate using the replication proteins of a host cell?

pathogens

parasites

parasitic worms

viruses

CHAPTER SUMMARY 17.1 Viruses Viruses are acellular entities that can usually only be seen with an electron microscope. Their genomes contain either DNA or RNA, and they replicate using the replication proteins of a host cell. Viruses are diverse, infecting archaea, bacteria, fungi, plants, and animals. Viruses consist of a nucleic-acid core surrounded by a protein capsid with or without an outer lipid envelope. Viral replication within a living cell always produces changes in the cell, sometimes resulting in cell death and sometimes slowly killing the infected cells. There are six basic stages in the virus replication cycle: attachment, penetration, uncoating, replication, assembly, and release. A viral infection may be productive, resulting in new virions, or nonproductive, meaning the virus remains inside the cell without producing new virions. Viruses cause a variety of diseases in humans. Many of these diseases can be prevented by the use of viral vaccines, which stimulate protective immunity against the virus without causing major disease. Viral vaccines may also be used in active viral infections, boosting the ability of the immune system to control or destroy the virus. Antiviral drugs that target enzymes and other protein products of viral genes have been developed and used with mixed success. Combinations of anti-HIV drugs have been used to effectively control the virus, extending the lifespan of infected individuals.

What type of virus is the flu caused by?

Mononucleosis

Rubella

pneumonia

influenza

Doesn't look like fun. The flu is caused by an influenza virus. And usually a slightly different virus every season.

Almost all leaves are specialized for what process?

sex

measurements

reactions

photosynthesis

null

Some inhibitor molecules bind to enzymes in a location where their binding induces a conformational change that reduces the affinity of the enzyme for its substrate. this type of inhibition is called allosteric what?

induction

secretion

mutation

inhibition

On the other hand, in noncompetitive inhibition, an inhibitor molecule binds to the enzyme in a location other than the active site, called an allosteric site, but still manages to block substrate binding to the active site. Some inhibitor molecules bind to enzymes in a location where their binding induces a conformational change that reduces the affinity of the enzyme for its substrate. This type of inhibition is called allosteric inhibition (Figure 4.9). Most allosterically regulated enzymes are made up of more than one polypeptide, meaning that they have more than one protein subunit. When an allosteric inhibitor binds to a region on an enzyme, all active sites on the protein subunits are changed slightly such that they bind their substrates with less efficiency. There are allosteric activators as well as inhibitors. Allosteric activators bind to locations on an enzyme away from the active site, inducing a conformational change that increases the affinity of the enzyme’s active site(s) for its substrate(s) (Figure 4.9).

During which process does carbon dioxide exit the cells, enter the bloodstream, travel back to the lungs, and get expired out of the body?

osmosis

peroxidation

inhalation

exhalation

The Respiratory System Take a breath in and hold it. Wait several seconds and then let it out. Humans, when they are not exerting themselves, breathe approximately 15 times per minute on average. This equates to about 900 breaths an hour or 21,600 breaths per day. With every inhalation, air fills the lungs, and with every exhalation, it rushes back out. That air is doing more than just inflating and deflating the lungs in the chest cavity. The air contains oxygen that crosses the lung tissue, enters the bloodstream, and travels to organs and tissues. There, oxygen is exchanged for carbon dioxide, which is a cellular waste material. Carbon dioxide exits the cells, enters the bloodstream, travels back to the lungs, and is expired out of the body during exhalation.

Exotic species, also known as invasive or non-native species often cause _______ when introduced to new environments.

harmony

radicalization

confusion

extinction

One of the main causes of extinction is introduction of exotic species into an environment. These exotic and new species can also be called invasive species or non-native species . These non-native species, being new to an area, may not have natural predators in the new habitat, which allows their populations to easily adapt and grow. Invasive species out-compete the native species for resources. Sometimes invasive species are so successful at living in a certain habitat that the native species go extinct ( Figure below ).

What is formed when light rays diverge behind a lens?

a projection

a hologram

a shadow

a virtual image

When light rays diverge behind a lens, a virtual image is formed. A virtual image is a manifestation of your brain (it traces the diverging rays backwards and forms an image), like the person you see “behind” a mirror’s surface when you brush your teeth (there's obviously no real light focused behind a mirror!). Since virtual images aren’t actually “anywhere,” you can’t place photographic film anywhere to capture them.

An equipotential line is a line along which the electric potential is wht?

changeable

increasing

decreasing

constant

An equipotential line is a line along which the electric potential is constant. An equipotential surface is a three-dimensional version of equipotential lines. Equipotential lines are always perpendicular to electric field lines. The process by which a conductor can be fixed at zero volts by connecting it to the earth with a good conductor is called grounding.

Keratin is an intracellular fibrous protein that gives hair, nails, and skin their hardness and this?

friction resistant properties

heat resistant properties

cold - resistant properties

water-resistant properties

The cells in all of the layers except the stratum basale are called keratinocytes. A keratinocyte is a cell that manufactures and stores the protein keratin. Keratin is an intracellular fibrous protein that gives hair, nails, and skin their hardness and water-resistant properties. The keratinocytes in the stratum corneum are dead and regularly slough away, being replaced by cells from the deeper layers (Figure 5.4).

The insect reaches full size, acquires wings, and becomes sexually mature after what final stage?

metamorphosis

pupae

larvae

molt

null

Body movements help circulate the hemolymph by periodically squeezing what?

the heart

the lungs

muscles

the sinuses

null

What is the name of the effect that causes air masses to move on a diagonal?

aurora borealis

polar effect

the headwind effect

the coriolis effect

Why do air masses move? Winds and jet streams push them along. Cold air masses tend to move toward the Equator. Warm air masses tend to move toward the poles. The Coriolis effect causes them to move on a diagonal. Many air masses move toward the northeast over the U. S. This is the same direction that global winds blow.

Peristalsis is necessary for what basic bodily function?

regeneration

reproduction

respiration

digestion

Describe peristalsis, and explain why it is necessary for digestion.

Radioactive isotopes have the same chemical properties as stable isotopes of the same element. still, how is radioactive isotope different from stable isotopes?

they absorb light

they absorb radiation

they emit magnetism

they emit radiation

Radioactive isotopes have the same chemical properties as stable isotopes of the same element, but they emit radiation, which can be detected. If we replace one (or more) atom(s) with radioisotope(s) in a compound, we can track them by monitoring their radioactive emissions. This type of compound is called a radioactive tracer (or radioactive label). Radioisotopes are used to follow the paths of biochemical reactions or to determine how a substance is distributed within an organism. Radioactive tracers are also used in many medical applications, including both diagnosis and treatment. They are used to measure engine wear, analyze the geological formation around oil wells, and much more. Radioisotopes have revolutionized medical practice (see Appendix M), where they are used extensively. Over 10 million nuclear medicine procedures and more than 100 million nuclear medicine tests are performed annually in the United States. Four typical examples of radioactive tracers used in medicine are technetium-99 ( 99 , thallium-201 43 Tc) , iodine-131 ( 131 , and sodium-24 ( 24 . Damaged tissues in the heart, liver, and lungs absorb certain ( 201 81 Tl) 11 Na) 53 I) compounds of technetium-99 preferentially. After it is injected, the location of the technetium compound, and hence the damaged tissue, can be determined by detecting the γ rays emitted by the Tc-99 isotope. Thallium-201 (Figure 21.24) becomes concentrated in healthy heart tissue, so the two isotopes, Tc-99 and Tl-201, are used together to study heart tissue. Iodine-131 concentrates in the thyroid gland, the liver, and some parts of the brain. It can therefore be used to monitor goiter and treat thyroid conditions, such as Grave’s disease, as well as liver and brain tumors. Salt solutions containing compounds of sodium-24 are injected into the bloodstream to help locate obstructions to the flow of blood.

What can be described in terms of physical properties and chemical properties as well as its defining states?

mass

energy

empty space

matter

Matter can be described in terms of physical properties and chemical properties.

Wetlands are extremely important as an ecosystem and as a filter for what?

storms

wind

clouds

pollutants

Wetlands are extremely important as an ecosystem and as a filter for pollutants.

Amphibians generally rely heavily on their moist skin for what with the environment?

sensory perception

cooling

competition

gas exchange

null

A change in species over time is known as?

divergence

variation

generation

evolution

Evolution is a change in species over time.

What type of event nearly always occurs at plate boundaries?

eruption

hurricane

tsunami

earthquake

Scientists are not able to predict earthquakes. Since nearly all earthquakes take place at plate boundaries, scientists can predict where an earthquake will occur ( Figure below ). This information helps communities to prepare for an earthquake. For example, they can require that structures are built to be earthquake safe.

Each f atom has one bonding pair and three lone pairs of what?

protons

ions

megatrons

electrons

There are two different types of electrons in the fluorine diatomic molecule. The bonding electron pair makes the covalent bond. Each F atom has three other pairs of electrons that do not participate in the bonding; they are called lone electron pairs. Each F atom has one bonding pair and three lone pairs of electrons. Covalent bonds can be made between different elements as well. One example is HF. Each atom starts out with an odd number of electrons in its valence shell:.

The embryo sac consists of only a few cells, one of which is the what?

sperm

mitochondria

dna

egg

null

What type of organisms collect the energy from the sun and turn it into organic compounds?

organelles

microbes

heterotrophs

autotrophs

If a plant gets hungry, it cannot walk to a local restaurant and buy a slice of pizza. So, how does a plant get the food it needs to survive? Plants are producers , which means they are able to make, or produce, their own food. They also produce the "food" for other organisms. Plants are also autotrophs. Autotrophs are the organisms that collect the energy from the sun and turn it into organic compounds. Using the energy from the sun, they produce complex organic compounds from simple inorganic molecules. So once again, how does a plant get the food it needs to survive?.

Force is a vector because it has what two things?

size and depth

matter and direction

space and time

size and direction

Force is a vector because it has both size and direction. Like other vectors, it can be represented by an arrow.

What type of rock makes up most of the earth?

Sedimentary

tuberous

Metamorphic

igneous

Most of the Earth is made of igneous rock. The entire mantle is igneous rock, as are some areas of the crust. One of the most common igneous rocks is granite ( Figure below ). Many mountain ranges are made of granite. People use granite for countertops, buildings, monuments and statues. Pumice is also an igneous rock. Perhaps you have used a pumice stone to smooth your skin. Pumice stones are put into giant washing machines with new jeans and tumbled around. The result is stone-washed jeans!.

The seven bones of the ankle are called the what?

termals

ankular

femurs

tarsals

The tarsals are the seven bones of the ankle. The ankle transmits the weight of the body from the tibia and the fibula to the foot. The metatarsals are the five bones of the foot. The phalanges are the 14 bones of the toes. Each toe consists of three phalanges, except for the big toe that has only two (Figure 38.15). Variations exist in other species; for example, the horse’s metacarpals and metatarsals are oriented vertically and do not make contact with the substrate.

What is the name for the amount of energy that is required in order to begin a chemical reaction?

conduction

function

catalytic

activation

Although the overall process involves a release of energy (the products are lower energy than the reactants), a certain initial amount of energy needs to be present before the reaction can occur. The amount of energy required to get over the "hump" in the reaction diagram is referred to as the activation energy of the reaction. At the top of the peak, the reactants form what is known as an activated complex. The activated complex is the highest energy state that must be achieved in order for reactants to convert into products.

Presence or absence of what feature distinguishes vertebrates from invertebrates?

heart

hair

scales

backbone

Animals are often identified as being either invertebrates or vertebrates. These are terms based on the skeletons of the animals. Vertebrates have a backbone made of bone or cartilage ( cartilage is a flexible supportive tissue. You have cartilage in your ear lobes. ). Invertebrates , on the other hand, have no backbone ( Figure below ). Invertebrates live just about anywhere. There are so many invertebrates on this planet that it is impossible to count them all. There are probably billions of billions of invertebrates. They come in many shapes and sizes, live practically anywhere and provide many services that are vital for the survival of other organisms, including us. They have been observed in the upper reaches of the atmosphere, in the driest of the deserts and in the canopies of the wettest rainforests. They can even be found in the frozen Antarctic or on the deepest parts of the ocean floor.

All the bones of the skull, except for the mandible, are joined to each other by a fibrous joint called what?

aperture

stucco

blade

suture

Suture All the bones of the skull, except for the mandible, are joined to each other by a fibrous joint called a suture. The fibrous connective tissue found at a suture (“to bind or sew”) strongly unites the adjacent skull bones and thus helps to protect the brain and form the face. In adults, the skull bones are closely opposed and fibrous connective tissue fills the narrow gap between the bones. The suture is frequently convoluted, forming a tight union that prevents most movement between the bones. (See Figure 9.5a. ) Thus, skull sutures are functionally classified as a synarthrosis, although some sutures may allow for slight movements between the cranial bones. In newborns and infants, the areas of connective tissue between the bones are much wider, especially in those areas on the top and sides of the skull that will become the sagittal, coronal, squamous, and lambdoid sutures. These broad areas of connective tissue are called fontanelles (Figure 9.6). During birth, the fontanelles provide flexibility to the skull, allowing the bones to push closer together or to overlap slightly, thus aiding movement of the infant’s head through the birth canal. After birth, these expanded regions of connective tissue allow for rapid growth of the skull and enlargement of the brain. The fontanelles greatly decrease in width during the first year after birth as the skull bones enlarge. When the connective tissue between the adjacent bones is reduced to a narrow layer, these fibrous joints are now called sutures. At some sutures, the connective tissue will ossify and be converted into bone, causing the adjacent bones to fuse to each other. This fusion between bones is called a synostosis (“joined by bone”). Examples of synostosis fusions between cranial bones are found both early and late in life. At the time of birth, the frontal and maxillary bones consist of right and left halves joined together by sutures, which disappear by the eighth year as the halves fuse together to form a single bone. Late in life, the sagittal, coronal, and lambdoid sutures of the skull will begin to ossify and fuse, causing the suture line to gradually disappear.

What do we use to keep track of electric potential energy?

wattage

temperature

amperage

voltage

Like gravity, the electric force can do work and has a potential energy associated with it. But like we use fields to keep track of electromagnetic forces, we use electric potential , or voltage to keep track of electric potential energy. So instead of looking for the potential energy of specific objects, we define it in terms of properties of the space where the objects are.

Ozone loss increases the amount of what high-energy radiation that strikes earth?

gamma rays

infrared

microwaves

ultraviolet

Ozone loss increases the amount of high-energy ultraviolet radiation that strikes Earth. This can cause ecological and health problems.

What are two simple and common types of capacitor connections?

flux and parallel

series and ionic

appearance and parallel

series and parallel

19.6 Capacitors in Series and Parallel Several capacitors may be connected together in a variety of applications. Multiple connections of capacitors act like a single equivalent capacitor. The total capacitance of this equivalent single capacitor depends both on the individual capacitors and how they are connected. There are two simple and common types of connections, called series and parallel, for which we can easily calculate the total capacitance. Certain more complicated connections can also be related to combinations of series and parallel.

What is the last step in scientific investigation?

migration of results

data management

document of results

communication of results

The last step in a scientific investigation is the communication of results with others.

Nematodes have an alimentary canal, but lack what?

nervous system

lymphatic system

metabolism system

circulatory system

null

What instrument is used to make objects in space appear closer?

mirror

microscope

GPS

telescope

Telescopes made objects in space seem closer. But they didn't make it any easier to visit them. Human space flight required something entirely different: rockets.

Which law predicts increasing entropy based on living systems?

kelper's

kinetic

planetary

thermodynamic

null

An amine is an organic compound that can be considered to be a derivative of what?

calcium

nitrogen

lead

ammonia

An amine is an organic compound that can be considered to be a derivative of ammonia (NH 3 ). The general structure of an amine can be abbreviated as R−NH 2 , where R is a carbon chain. However, similar to alcohols, amines can be primary, secondary, or tertiary.

The hormones epinephrine and norepinephrine are associated with what rhyming mechanism?

bright - or - flight

light - or- flight

right - or - flight

fight-or-flight

Epinephrine and Norepinephrine The catecholamines, epinephrine and NE, secreted by the adrenal medulla form one component of the extended fight-orflight mechanism. The other component is sympathetic stimulation. Epinephrine and NE have similar effects: binding to the beta-1 receptors, and opening sodium and calcium ion chemical- or ligand-gated channels. The rate of depolarization is increased by this additional influx of positively charged ions, so the threshold is reached more quickly and the period of repolarization is shortened. However, massive releases of these hormones coupled with sympathetic stimulation may actually lead to arrhythmias. There is no parasympathetic stimulation to the adrenal medulla.

Matter is composed of exceedingly small particles called what?

ions

crystals

cells

atoms

Atomic Theory through the Nineteenth Century The earliest recorded discussion of the basic structure of matter comes from ancient Greek philosophers, the scientists of their day. In the fifth century BC, Leucippus and Democritus argued that all matter was composed of small, finite particles that they called atomos, a term derived from the Greek word for “indivisible. ” They thought of atoms as moving particles that differed in shape and size, and which could join together. Later, Aristotle and others came to the conclusion that matter consisted of various combinations of the four “elements”—fire, earth, air, and water—and could be infinitely divided. Interestingly, these philosophers thought about atoms and “elements” as philosophical concepts, but apparently never considered performing experiments to test their ideas. The Aristotelian view of the composition of matter held sway for over two thousand years, until English schoolteacher John Dalton helped to revolutionize chemistry with his hypothesis that the behavior of matter could be explained using an atomic theory. First published in 1807, many of Dalton’s hypotheses about the microscopic features of matter are still valid in modern atomic theory. Here are the postulates of Dalton’s atomic theory. Matter is composed of exceedingly small particles called atoms. An atom is the smallest unit of an element.

Gases have no definite shape or what?

smell

growth

mass

volume

Gases have no definite shape or volume.

Elements have orbitals that are filled with what?

photons

particles

ions

electrons

enters a d orbital. The valence electrons (those added after the last noble gas configuration) in these elements include the ns and (n – 1) d electrons. The official IUPAC definition of transition elements specifies those with partially filled d orbitals. Thus, the elements with completely filled orbitals (Zn, Cd, Hg, as well as Cu, Ag, and Au in Figure 6.30) are not technically transition elements. However, the term is frequently used to refer to the entire d block (colored yellow in Figure 6.30), and we will adopt this usage in this textbook. Inner transition elements are metallic elements in which the last electron added occupies an f orbital. They.

Most protein antigens require signals from helper t cells (th2) to proceed to make what?

antioxidant

protein

bacterium

antibody

B Cell Differentiation and Activation B cells differentiate in the bone marrow. During the process of maturation, up to 100 trillion different clones of B cells are generated, which is similar to the diversity of antigen receptors seen in T cells. B cell differentiation and the development of tolerance are not quite as well understood as it is in T cells. Central tolerance is the destruction or inactivation of B cells that recognize self-antigens in the bone marrow, and its role is critical and well established. In the process of clonal deletion, immature B cells that bind strongly to self-antigens expressed on tissues are signaled to commit suicide by apoptosis, removing them from the population. In the process of clonal anergy, however, B cells exposed to soluble antigen in the bone marrow are not physically deleted, but become unable to function. Another mechanism called peripheral tolerance is a direct result of T cell tolerance. In peripheral tolerance, functional, mature B cells leave the bone marrow but have yet to be exposed to self-antigen. Most protein antigens require signals from helper T cells (Th2) to proceed to make antibody. When a B cell binds to a self-antigen but receives no signals from a nearby Th2 cell to produce antibody, the cell is signaled to undergo apoptosis and is destroyed. This is yet another example of the control that T cells have over the adaptive immune response. After B cells are activated by their binding to antigen, they differentiate into plasma cells. Plasma cells often leave the secondary lymphoid organs, where the response is generated, and migrate back to the bone marrow, where the whole differentiation process started. After secreting antibodies for a specific period, they die, as most of their energy is devoted to making antibodies and not to maintaining themselves. Thus, plasma cells are said to be terminally differentiated. The final B cell of interest is the memory B cell, which results from the clonal expansion of an activated B cell. Memory B cells function in a way similar to memory T cells. They lead to a stronger and faster secondary response when compared to the primary response, as illustrated below.

What is caused by the buildup of stress in the rocks?

debris tilting

ground fall

ground dropping

ground tilting

There are other possible signs before an earthquake. The ground may tilt. Ground tilting is caused by the buildup of stress in the rocks. This may happen before a large earthquake, but it doesn't always. Water levels in wells may fluctuate. This is because water may move into or out of fractures before an earthquake. This is also an uncertain way to predict an earthquake. The difference in arrival times of P-waves and S-waves may decrease just before an earthquake occurs.

Forty percent of your body mass is made up of what?

cardiac muscle

skin

blood

skeletal muscle

Skeletal muscle is attached to bones and its contraction makes possible locomotion, facial expressions, posture, and other voluntary movements of the body. Forty percent of your body mass is made up of skeletal muscle. Skeletal muscles generate heat as a byproduct of their contraction and thus participate in thermal homeostasis. Shivering is an involuntary contraction of skeletal muscles in response to perceived lower than normal body temperature. The muscle cell, or myocyte,.

Water is composed of which two elements?

carbon and dioxide

oxygen and nitrogen

hydrogen and nitrogen

hydrogen and oxygen

Water is a binary compound composed of hydrogen and oxygen. The hydrogen and oxygen gases produced in the reaction are both diatomic molecules.

A polar covalent bond is a covalent bond between different atoms that attract the shared electrons by different amounts and cause an imbalance of what ?

neutron distribution

proton distribution

ions distribution

electron distribution

EXAMPLE 13 Describe the bonding in the nitrite ion in terms of a combination of hybrid atomic orbitals and molecular orbitals. Lewis dot structures and the VSEPR model predict that the NO2− ion is bent. Given: chemical species and molecular geometry Asked for: bonding description using hybrid atomic orbitals and molecular orbitals Strategy: A Calculate the number of valence electrons in NO2−. From the structure, predict the type of atomic orbital hybridization in the ion. B Predict the number and type of molecular orbitals that form during bonding. Use valence electrons to fill these orbitals and then calculate the number of electrons that remain. C If there are unhybridized orbitals, place the remaining electrons in these orbitals in order of increasing energy. Calculate the bond order and describe the bonding. Solution: A The lone pair of electrons on nitrogen and a bent structure suggest that the bonding in NO 2− is similar to the bonding in ozone. This conclusion is supported by the fact that nitrite also contains 18 valence electrons (5 from N and 6 from each O, plus 1 for the −1 charge). The bent structure implies that the nitrogen is sp2 hybridized. B If we assume that the oxygen atoms are sp2 hybridized as well, then we can use twosp2 hybrid orbitals on each oxygen and one sp2 hybrid orbital on nitrogen to accommodate the five lone pairs of electrons. Two sp2 hybrid orbitals on nitrogen form σ bonds with the remaining sp2 hybrid orbital on each oxygen.

What two things are excess proteins converted into?

fructose or triglycerides

sucrose or triglycerides

glucose or sucrose

glucose or triglycerides

serve as a metabolic fuel source. Proteins are not stored for later use, so excess proteins must be converted into glucose or triglycerides, and used to supply energy or build energy reserves. Although the body can synthesize proteins from amino acids, food is an important source of those amino acids, especially because humans cannot synthesize all of the 20 amino acids used to build proteins. The digestion of proteins begins in the stomach. When protein-rich foods enter the stomach, they are greeted by a mixture of the enzyme pepsin and hydrochloric acid (HCl; 0.5 percent). The latter produces an environmental pH of 1.5–3.5 that denatures proteins within food. Pepsin cuts proteins into smaller polypeptides and their constituent amino acids. When the food-gastric juice mixture (chyme) enters the small intestine, the pancreas releases sodium bicarbonate to neutralize the HCl. This helps to protect the lining of the intestine. The small intestine also releases digestive hormones, including secretin and CCK, which stimulate digestive processes to break down the proteins further. Secretin also stimulates the pancreas to release sodium bicarbonate. The pancreas releases most of the digestive enzymes, including the proteases trypsin, chymotrypsin, and elastase, which aid protein digestion. Together, all of these enzymes break complex proteins into smaller individual amino acids (Figure 24.17), which are then transported across the intestinal mucosa to be used to create new proteins, or to be converted into fats or acetyl CoA and used in the Krebs cycle.

What is an individual living creature called?

protist

amino

species

organism

An individual living creature is called an organism . There are many characteristics that living organisms share. They all:.

What kind of a reaction if peptide bond formation?

recharge synthesis reaction

molten synthesis reaction

reversed synthesis reaction

dehydration synthesis reaction

Figure 3.24 Peptide bond formation is a dehydration synthesis reaction. The carboxyl group of one amino acid is linked to the amino group of the incoming amino acid. In the process, a molecule of water is released.

What are the elements of group 17 (fluorine, chlorine, bromine, iodine, and astatine) called?

antioxidants

metals

liquids

halogens

The elements of Group 17 (fluorine, chlorine, bromine, iodine, and astatine) are called the halogens . The halogens all have the general electron configuration n s 2 n p 5 , giving them seven valence electrons. They are one electron short of having full outer s and p sublevels, which makes them very reactive. They undergo especially vigorous reactions with the reactive alkali metals. In their pure elemental forms, chlorine and fluorine are gases at room temperature, bromine is a dark orange liquid, and iodine is a dark purple-gray solid. Astatine is so rare that its properties are mostly unknown.

What is the term for growing towards gravity?

pollenation

surviving

spirogyra

geotropism

As you read earlier in this chapter, plant roots always grow downward because specialized cells in root caps detect and respond to gravity. This is an example of a tropism. A tropism is a turning toward or away from a stimulus in the environment. Growing toward gravity is called geotropism. Plants also exhibit phototropism, or growing toward a light source. This response is controlled by a plant growth hormone called auxin. As shown in Figure below , auxin stimulates cells on the dark side of a plant to grow longer. This causes the plant to bend toward the light.

What does our solar system orbit over the course of hundreds of millions of years?

retrograde center

volcanic center

a black hole

galactic center

Our solar system orbits the center of the galaxy as the galaxy spins. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago.

What do inherited immunodeficiencies arise from?

stem cells

Allopatric speciation

viral infections

gene mutations

Immunodeficiencies As you have seen, the immune system is quite complex. It has many pathways using many cell types and signals. Because it is so complex, there are many ways for it to go wrong. Inherited immunodeficiencies arise from gene mutations that affect specific components of the immune response. There are also acquired immunodeficiencies with potentially devastating effects on the immune system, such as HIV.

What kinds of winds can be found in belts that span the entire circumference of the earth?

Periodic winds

Trade winds

Local Winds

global winds

Global winds are winds that occur in belts that go all around the planet ( Figure below ). Like local winds, global winds are caused by unequal heating of the atmosphere.

Touching, coughing, or sneezing are examples of directly spreading what microorganisms, which cause diseases like tetanus?

algae

pollen

viruses

bacteria

You have ten times as many bacteria as human cells in your body. Most of these bacteria are harmless. However, bacteria can also cause disease. Examples of bacterial diseases include tetanus, syphilis, and food poisoning. Bacteria may spread directly from one person to another. For example, they can spread through touching, coughing, or sneezing. They may also spread via food, water, or objects.

Which blood pressure is highest when the heart contracts during ventricular systole?

diastolic

systolic

resting rate

arterial

null

All the members of a species that live in the same area form a what?

habitat

biome

biosphere

population

All the members of a species that live in the same area form a population . Many different species live together in an ecosystem. All their populations make up a community . What populations live together in the grassland pictured below ( Figure above )?.

New species may be created by natural selection and one other way. what is the other way?

squalling selection

fake selection

obvious selection

artifical selection

Speciation, the creation of a new species, can happen through natural selection or artificial selection.

What type of illness is influenza?

cardiac illness

mental illness

stomach illness

respiratory illness

Influenza, or flu, is a contagious respiratory illness caused by influenza viruses. Influenza spreads around the world in seasonal epidemics. An epidemic is an outbreak of a disease within a population of people during a specific time. Every year in the United States, about 200,000 people are hospitalized and 36,000 people die from the flu. Flu pandemics can kill millions of people. A pandemic is an epidemic that spreads through human populations across a large region (for example a continent), or even worldwide. Three influenza pandemics occurred in the 20th century and killed tens of millions of people, with each of these pandemics being caused by the appearance of a new strain of the virus. Most influenza strains can be inactivated easily by disinfectants and detergents.

In which process do paired chromosomes normally separate from each other?

diffusion

mutations

gametes

meiosis

In the process of meiosis, paired chromosomes normally separate from each other. They end up in different gametes. Sometimes, however, errors occur. The paired chromosomes fail to separate. When this happens, some gametes get an extra copy of a chromosome. Other gametes are missing a chromosome. If one of these gametes is fertilized and survives, a chromosomal disorder results. You can see examples of such disorders in Table below.

About how many years ago did our solar system begin?

60 billion

3 billion

10 billion

5 billion years

Our solar system began about 5 billion years ago. The Sun, planets and other solar system objects all formed at about the same time.

What is the energy change called when a neutral atom gains an electron?

nuclear fission

fusion gain

mass affinity

electron affinity

The energy change that occurs when a neutral atom gains an electron is called its electron affinity . When energy is released in a chemical reaction or process, that energy is expressed as a negative number. The figure below shows electron affinities in kJ/mole for the representative elements. Electron affinities are measured on atoms in the gaseous state and are very difficult to measure accurately.

What kind of interference characteristics does matter have compared to any wave?

when

DIfferent

one

same

29.7 Probability: The Heisenberg Uncertainty Principle • Matter is found to have the same interference characteristics as any other wave. • There is now a probability distribution for the location of a particle rather than a definite position. • Another consequence of the wave character of all particles is the Heisenberg uncertainty principle, which limits the precision with which certain physical quantities can be known simultaneously. For position and momentum, the uncertainty principle is.

Which can cause serious metabolic disorders, too little or too much thyroid hormone in the blood?

too little only

neither

too much only

both

null

How many colors of light can the human eye detect?

six

infinite

nine

three

The human eye can detect only three colors of light. What three colors are they? How can we perceive other colors of light?.

The length of a linear accelerator and the size of the d-shaped electrodes in a cyclotron severely limit the kinetic energy that particles can attain in these devices. these limitations can be overcome by using one of these?

magnet

plastic

metal

synchrotron

To achieve the same outcome in less space, a particle accelerator called a cyclotronforces the charged particles to travel in a circular path rather than a linear one. The particles are injected into the center of a ring and accelerated by rapidly alternating the polarity of two large D-shaped electrodes above and below the ring, which accelerates the particles outward along a spiral path toward the target. The length of a linear accelerator and the size of the D-shaped electrodes in a cyclotron severely limit the kinetic energy that particles can attain in these devices. These limitations can be overcome by using a synchrotron, a hybrid of the two designs. A synchrotron contains an evacuated tube similar to that of a linear accelerator, but the tube is circular and can be more than a mile in diameter (Figure 20.10 "A Synchrotron"). Charged particles are accelerated around the circle by a series of magnets whose polarities rapidly alternate.

The mammalian sense of touch also relies on mechanoreceptors that are the dendrites of sensory?

electrons

ions

nerves

neurons

null

What is the largest known animal?

the white shark

the elephant

the giraffe

the blue whale

Living things in the oceans are called marine organisms . They range from tiny bacteria to the largest known animal, the blue whale. All are adapted for life in salt water. Most are adapted for extreme pressures.

Polymers can disassemble by the reverse process called what?

electrolysis

mitosis

dehydration

hydrolysis

null

Purple loosestrife is a european wildflower that was introduced to which continent in the 1800's?

australia

south america

asia

north america

Purple loosestrife is a European wildflower that was introduced to North America in the early 1800s. It soon spread to take over wetland habitats throughout the U. S. and Canada. Purple loosestrife replaces native wetland plants and threatens native wildlife by eliminating natural foods and cover. It also blocks irrigation systems.

The male gametangium that produces sperm is also called what?

trichina

xerophyte

echinacea

antheridium

Gametangia in the Seedless Plants Gametangia (singular, gametangium) are structures on the gametophytes of seedless plants in which gametes are produced by mitosis. The male gametangium, the antheridium, releases sperm. Many seedless plants produce sperm equipped with flagella that enable them to swim in a moist environment to the archegonia, the female gametangium. The embryo develops inside the archegonium as the sporophyte. Apical Meristems The shoots and roots of plants increase in length through rapid cell division within a tissue called the apical meristem (Figure 14.5). The apical meristem is a cap of cells at the shoot tip or root tip made of undifferentiated cells that continue to proliferate throughout the life of the plant. Meristematic cells give rise to all the specialized tissues of the plant. Elongation of the shoots and roots allows a plant to access additional space and resources: light in the case of the shoot, and water and minerals in the case of roots. A separate meristem, called the lateral meristem, produces cells that increase the diameter of stems and tree trunks. Apical meristems are an adaptation to allow vascular plants to grow in directions essential to their survival: upward to greater availability of sunlight, and downward into the soil to obtain water and essential minerals.

What part is written first when naming an ionic compound?

carbonate

anion

Atom

cation

Ionic compounds are named by writing the name of the cation followed by the name of the anion.

How does adding salt to water affect the boiling point?

maintains

no difference

reduces

increases

Salt is often added to boiling water when preparing spaghetti or other pasta. One reason is to add flavor to the food. Some people believe that the addition of salt increases the boiling point of the water. Technically, they are correct, but the increase is rather small. You would need to add over 100 grams of NaCl to a liter of water to increase the boiling point a couple of degrees, which is just not healthy.

What mineral is used in jewelry because of its striking greenish-blue color?

lime

aqua

glass

turquoise

Diamonds have many valuable properties. Diamonds are extremely hard and are used for industrial purposes. The most valuable diamonds are large, well-shaped and sparkly. Turquoise is another mineral that is used in jewelry because of its striking greenish-blue color. Many minerals have interesting appearances. Specific terms are used to describe the appearance of minerals.

Ionic bonds are formed between which ions?

with the same charges

with multiple charges

with random charges

with opposite charges

Ionic bonds are formed between ions with opposite charges. For instance, positively charged sodium ions and negatively charged chloride ions bond together to make crystals of sodium chloride, or table salt, creating a crystalline molecule with zero net charge. Certain salts are referred to in physiology as electrolytes (including sodium, potassium, and calcium), ions necessary for nerve impulse conduction, muscle contractions and water balance. Many sports drinks and dietary supplements provide these ions to replace those lost from the body via sweating during exercise.

What causes most ocean waves?

tides

Gravity

rains

winds

Most ocean waves are caused by winds. A wave is the transfer of energy through matter. A wave that travels across miles of ocean is traveling energy, not water. Ocean waves transfer energy from wind through water. The energy of a wave may travel for thousands of miles. The water itself moves very little. Figure below shows how water molecules move when a wave goes by.

What work by lowering the activation energy of reactions and are needed to speed up chemical reactions in organisms?

molecules

compounds

Proteins

enzymes

Enzymes are needed to speed up chemical reactions in organisms. They work by lowering the activation energy of reactions.

Exon skipping is an example of what type of splicing?

comprehensive

inclusive

proactive

alternative

One example of alternative splicing is with exon skipping. The D. melanogaster (fruit fly) doublesex (dsx) gene is involved in the fly's determination system. Pre-mRNAs from this gene contain 6 eons, numbered 1-6. In males, exons 1,2,3,5,and 6 are spliced together to form the mRNA, which encodes a transcriptional regulatory protein required for male development. In females, exons 1, 2, 3, and 4 are joined, and a polyadenylation signal in exon 4 causes cleavage of the mRNA at that point. The resulting mRNA is a transcriptional regulatory protein required for female development.

What is the term for the distance between any two corresponding points on adjacent waves?

tessellation

osscilation

bandwidth

wavelength

A wave cycle consists of one complete wave – starting at the zero point, going up to a wave crest , going back down to a wave trough , and back to the zero point again. The wavelength of a wave is the distance between any two corresponding points on adjacent waves. It is easiest to visualize the wavelength of a wave as the distance from one wave crest to the next. In an equation, wavelength is represented by the Greek letter lambda . Depending on the type of wave, wavelength can be measured in meters, centimeters, or nanometers (1 m = 10 9 nm). The frequency , represented by the Greek letter nu , is the number of waves that pass a certain point in a specified amount of time. Typically, frequency is measured in units of cycles per second or waves per second. One wave per second is also called a Hertz (Hz) and in SI units is a reciprocal second (s -1 ).

Typically, what feature of an angiosperm has four main parts known as the calyx, corolla, androecium, and gynoecium?

glass

leaves

stem

flower

Sexual Reproduction in Angiosperms The lifecycle of angiosperms follows the alternation of generations explained previously. The haploid gametophyte alternates with the diploid sporophyte during the sexual reproduction process of angiosperms. Flowers contain the plant’s reproductive structures. Flower Structure A typical flower has four main parts—or whorls—known as the calyx, corolla, androecium, and gynoecium (Figure 32.3). The outermost whorl of the flower has green, leafy structures known as sepals. The sepals, collectively called the calyx, help to protect the unopened bud. The second whorl is comprised of petals—usually, brightly colored—collectively called the corolla. The number of sepals and petals varies depending on whether the plant is a monocot or dicot. In monocots, petals usually number three or multiples of three; in dicots, the number of petals is four or five, or multiples of four and five. Together, the calyx and corolla are known as the perianth. The third whorl contains the male reproductive structures and is known as the androecium. The androecium has stamens with anthers that contain the microsporangia. The innermost group of structures in the flower is the gynoecium, or the female reproductive component(s). The carpel is the individual unit of the gynoecium and has a stigma, style, and ovary. A flower may have one or multiple carpels.

8each cell-surface receptor has three main components: an external ligand-binding domain, a hydrophobic membrane spanning region, and a(n) what domain inside the cell?

isolated

inocent

molecular

intracellular

Cell-Surface Receptors Cell-surface receptors, also known as transmembrane receptors, are cell surface, membrane-anchored (integral) proteins that bind to external ligand molecules. This type of receptor spans the plasma membrane and performs signal transduction, in which an extracellular signal is converted into an intercellular signal. Ligands that interact with cell-surface receptors do not have to enter the cell that they affect. Cell-surface receptors are also called cell-specific proteins or markers because they are specific to individual cell types. Because cell-surface receptor proteins are fundamental to normal cell functioning, it should come as no surprise that a malfunction in any one of these proteins could have severe consequences. Errors in the protein structures of certain receptor molecules have been shown to play a role in hypertension (high blood pressure), asthma, heart disease, and cancer. Each cell-surface receptor has three main components: an external ligand-binding domain, a hydrophobic membranespanning region, and an intracellular domain inside the cell. The ligand-binding domain is also called the extracellular domain. The size and extent of each of these domains vary widely, depending on the type of receptor.

Special cell in the epidermis of the skin that produces the brown pigment called what?

melatonin

cytoplasm

selenium

melanin

special cell in the epidermis of the skin that produces the brown pigment called melanin.

What are the most abundant source of energy found in most foods?

vitamins

fats

proteins

carbohydrates

Carbohydrates are the most abundant source of energy found in most foods. The simplest carbohydrates, also called simple sugars, are plentiful in fruits. A monosaccharide is a carbohydrate consisting of one sugar unit. Common examples of simple sugars or monosaccharides are glucose and fructose. Both of these monosaccharides are referred to as hexoses since they have six carbons. Glucose is abundant in many plant sources and makes up sweetners such as corn sugar or grape sugar. Fructose occurs in a great many fruits and is also found in honey. These sugars are structural isomers of one another, with the difference being that glucose contains an aldehyde functional group whereas fructose contains a ketone functional group.

What is considered to not be a form of precipitation?

snow

rain

condensation

fog

null

Both the initiation and inhibition of cell division are triggered by events external to the cell when it is about to begin which process?

extraction

mutation

isolation

replication

Regulation of the Cell Cycle by External Events Both the initiation and inhibition of cell division are triggered by events external to the cell when it is about to begin the replication process. An event may be as simple as the death of a nearby cell or as sweeping as the release of growthpromoting hormones, such as human growth hormone (HGH). A lack of HGH can inhibit cell division, resulting in dwarfism, whereas too much HGH can result in gigantism. Crowding of cells can also inhibit cell division. Another factor that can initiate cell division is the size of the cell; as a cell grows, it becomes inefficient due to its decreasing surface-tovolume ratio. The solution to this problem is to divide. Whatever the source of the message, the cell receives the signal, and a series of events within the cell allows it to proceed into interphase. Moving forward from this initiation point, every parameter required during each cell cycle phase must be met or the cycle cannot progress.

The binding of an antigen receptor to an epitope initiates events that activate the?

monocyte

endothelial

dendritic

lymphocyte

null