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Insulin is made up of how many polypeptide chains? | twelve | three | four | two | |
What is the term for the energy of movement? | molecular energy | potential energy | intrinsic energy | mechanical energy | 1. Mechanical energy is the energy of movement. It is found in objects that are moving or have the potential to move. |
What type of organisms are helpless at birth and require lots of help from their parents? | precocial organisms | Microorganisms | multicellular organisms | altricial organisms | Organisms can use different strategies to increase their reproduction rate. Altricial organisms are helpless at birth, and their parents give them a lot of care. This care is often seen in bird species. ( Figure below ). Altricial birds are usually born blind and without feathers. Compared to precocial organisms, altricial organisms have a longer period of development before they reach maturity. Precocial organisms, such as the geese shown below, can take care of themselves at birth and do not require help from their parents ( Figure below ). In order to reproduce as much as possible, altricial and precocial organisms must use very different strategies. |
Metallic bonds allow metals to do what, in the manner of a willow tree? | grow | break easily | stand tall | bend without breaking | The thick, rigid trunk of the oak tree on the left might crack and break in a strong wind. The slim, flexible trunk of the willow tree on the right might bend without breaking. In one way, metals are like willow trees. They can bend without breaking. That’s because metals form special bonds called metallic bonds. |
What is a substance that can not be broken down any further into other substances? | unbreakable substance | pure molecule | pure material | pure substance | pure substance that cannot be broken down into other types of substances. |
What three characteristics do waves have? | spin, refraction, and deflection | structure , refraction and deflection | theory , refraction and deflection | reflection, refraction and deflection | Most waves approach the shore at an angle. The part of the wave that is nearer the shore reaches shallow water sooner than the part that is farther out. The shallow part of the wave "feels" the bottom first. This slows down the inshore part of the wave and makes the wave "bend. " This bending is called refraction . |
What organ creates bile? | heart | kidney | pancreas | liver | The liver is an organ of both digestion and excretion. It produces a fluid called bile , which is secreted into the duodenum. Some bile also goes to the gall bladder , a sac-like organ that stores and concentrates bile and then secretes it into the small intestine. In the duodenum, bile breaks up large globules of lipids into smaller globules that are easier for enzymes to break down. Bile also reduces the acidity of food entering from the highly acidic stomach. This is important because digestive enzymes that work in the duodenum need a neutral environment. The pancreas contributes to the neutral environment by secreting bicarbonate, a basic substance that neutralizes acid. |
What is the smallest and most fundamental unit of matter, consisting of a nucleus surrounded by electrons? | neutron | proton | molecule | atom | Levels of Organization of Living Things Living things are highly organized and structured, following a hierarchy that can be examined on a scale from small to large. The atom is the smallest and most fundamental unit of matter. It consists of a nucleus surrounded by electrons. Atoms form molecules. A molecule is a chemical structure consisting of at least two atoms held together by one or more chemical bonds. Many molecules that are biologically important are macromolecules, large molecules that are typically formed by polymerization (a polymer is a large molecule that is made by combining smaller units called monomers, which are simpler than macromolecules). An example of a macromolecule is deoxyribonucleic acid (DNA) (Figure 1.15), which contains the instructions for the structure and functioning of all living organisms. |
Mutation of beneficial proto-oncogenes is a prime culprit in what disease? | obesity | heart disease | diabetes | cancer | The products of proto-oncogenes are required for normal growth, repair and homeostasis. However, when these genes are mutated, they turn into oncogenes and play a role in the development of cancer. Proto-oncogenes may be growth factors, transcription factors, or other proteins involved in regulation. A very common oncogene, ras , is normally a regulatory GTPase that switches a signal transduction chain on and off. Ras and Ras-related proteins are products of oncogenes found in 20% to 30% of human tumors. The transcription factor myc is an oncogene often seen mutated in Burkitt’s lymphoma, a rare type of lymphoma, a cancer of the lymphocytes. |
What happens to charges whenever they are accelerated? | they die | they fuse | they darken | they radiate | Receiving Electromagnetic Waves Electromagnetic waves carry energy away from their source, similar to a sound wave carrying energy away from a standing wave on a guitar string. An antenna for receiving EM signals works in reverse. And like antennas that produce EM waves, receiver antennas are specially designed to resonate at particular frequencies. An incoming electromagnetic wave accelerates electrons in the antenna, setting up a standing wave. If the radio or TV is switched on, electrical components pick up and amplify the signal formed by the accelerating electrons. The signal is then converted to audio and/or video format. Sometimes big receiver dishes are used to focus the signal onto an antenna. In fact, charges radiate whenever they are accelerated. When designing circuits, we often assume that energy does not quickly escape AC circuits, and mostly this is true. A broadcast antenna is specially designed to enhance the rate of electromagnetic radiation, and shielding is necessary to keep the radiation close to zero. Some familiar phenomena are based on the production of electromagnetic waves by varying currents. Your microwave oven, for example, sends electromagnetic waves, called microwaves, from a concealed antenna that has an oscillating current imposed on it. |
What is it in bone marrow transplants that may cause a graft versus host reaction? | cancer | tumors | neutrophils | lymphocytes | |
The vagina starts at the vulva and ends where? | pelvic brim | testicle | clitoris | the uterus | The vagina is a tube-like structure about 9 centimeters (3.5 inches) long. It begins at the vulva and extends upward to the uterus. It has muscular walls lined with mucous membranes. The vagina has two major reproductive functions. It receives sperm during sexual intercourse, and it provides a passageway for a baby to leave the mother’s body during birth. |
Regulatory proteins bind to regulatory elements to control what? | growth | mutation | differentiation | transcription | Regulation of Transcription. Regulatory proteins bind to regulatory elements to control transcription. The regulatory elements are embedded within the DNA. |
Microfilaments are mostly concentrated just beneath what? | the cytoplasm | the nucleus | the cell wall | the cell membrane | Microfilaments , shown as (b) in Figure below , are made of two thin actin chains that are twisted around one another. Microfilaments are mostly concentrated just beneath the cell membrane, where they support the cell and help the cell keep its shape. Microfilaments form cytoplasmatic extentions, such as pseudopodia and microvilli , which allow certain cells to move. The actin of the microfilaments interacts with the protein myosin to cause contraction in muscle cells. Microfilaments are found in almost every cell, and are numerous in muscle cells and in cells that move by changing shape, such as phagocytes (white blood cells that search the body for bacteria and other invaders). |
What term is used for any combination of two or more atoms? | nucleus | element | synthesis | molecule | A molecule is any combination of two or more atoms. The oxygen in the air we breathe is two oxygen atoms connected by a chemical bond to form O 2 , or molecular oxygen. A carbon dioxide molecule is a combination of one carbon atom and two oxygen atoms, CO 2 . Because carbon dioxide includes two different elements, it is a compound as well as a molecule. |
What is biomass made into fuel called? | renewable fuel | benign fuel | toxic fuel | bio fuel | More recently, people have learned to process biomass to make fuel. This is called biofuel . Biofuel is created from crops, such as corn or algae. Biofuel is unique among renewable energy sources. This is because it is liquid. Unlike solar energy, for example, biofuels can be used in a car ( Figure below ). Biofuels burn more cleanly than fossil fuels. They create less pollution and less carbon dioxide. Biofuels, such as ethanol, are added to gasoline. This cuts down the amount of fossil fuels that are used. |
What type of thin lava forms shapes and tubes as it flows? | xerophyte | spicule | xeric | pāhoehoe | Pāhoehoe lava is thinner than a'a, and flows more readily. Its surface looks more wrinkly and smooth. Pāhoehoe lava flows in a series of lobes that form strange twisted shapes and natural rock sculptures ( Figure below ). Pāhoehoe lava can form lava tubes. The outer layer of the lava flow cools and solidifies. The inner part of the flow remains fluid. The fluid lava flows through and leaves behind a tube ( Figure below ). |
The nucleolus, which makes ribosomes, is located within what cell structure? | epidermis | mitochondria | Golgi apparatus | nucleus | The nucleolus, which makes ribosomes, is also within the nucleus. |
Electrons flow through the electrolyte from the ________ to __________ electrode. | positive; negative | neutral; negative | negative; neutral | negative; positive | Both dry and wet cells work the same basic way. The electrodes react chemically with the electrolyte, causing one electrode to give up electrons and the other electrode to accept electrons. In the case of zinc and carbon electrodes, the zinc electrode attracts electrons and becomes negatively charged, while the carbon electrode gives up electrons and becomes positively charged. Electrons flow through the electrolyte from the negative to positive electrode. If wires are used to connect the two electrodes at their terminal ends, electric current will flow through the wires and can be used to power a light bulb or other electric device. |
What is the name of the part that connects the vagina with the uterus? | vulva | urethra | ovary | cervix | The uterus is a hollow organ with muscular walls. The part that connects the vagina with the uterus is called the cervix . The uterus is where a baby develops until birth. The walls of the uterus grow bigger as the baby grows. The muscular walls of the uterus push the baby out during birth. |
No-till farming is one effort to combat what, caused by typical farming practices? | pollution | habitat destruction | drought | soil erosion | The photos in Figure below show how farming practices can increase soil erosion. Plant roots penetrate the soil and keep it from eroding. Plowing turns over bare soil and cuts through plant roots. Bare soil is exposed to wind and water. In the past, farmers always plowed fields before planting. Some farmers now use no-till farming, which does not disturb the soil as much. |
Geysers are created when what is heated beneath the earth's surface? | air | magma | gases | water | Geysers are also created by water that is heated beneath the Earth’s surface. The water may become superheated by magma. It becomes trapped in a narrow passageway. The heat and pressure build as more water is added. When the pressure is too much, the superheated water bursts out onto the surface. This is a geyser . |
Increasing voltage with a higher-volt battery does what to the current? | decreases it | blocks it | stops it | increases it | Ohm’s law may be easier to understand with an analogy. Current flowing through a wire is like water flowing through a hose. Increasing voltage with a higher-volt battery increases the current. This is like opening the tap wider so more water flows through the hose. Increasing resistance reduces the current. This is like stepping on the hose so less water can flow through it. If you still aren’t sure about the relationships among current, voltage, and resistance, watch the video at this URL: http://www. youtube. com/watch?v=KvVTh3ak5dQ. |
Hydrogen peroxide will decompose over time to produce _______ gas. | water and carbon dioxide | methane | hydrogen and helium | water and oxygen | Again, substances in all states of matter commonly participate in decomposition reactions. For example, hydrogen peroxide will decompose over time to produce water and oxygen gas according to the following equation:. |
What kind of pipettes are suitable for measuring very small amounts of liquids? | frozen pipettes | clutch pipettes | macropipettes | micropipettes | Pipettes are small, but important tools in many biology labs. Micropipettes, such as the ones shown here, are calibrated to measure very small amounts of liquids. For example, 100 microliters (100 µL) is about half the volume of your little finger tip; or even 1 µL, which is much smaller than a drop of water. |
What is the measure of the force of gravity pulling down on an object called? | volume | factor | mass | weight | Weight is a measure of the force of gravity pulling down on an object. Buoyant force pushes up on an object. Weight and buoyant force together determine whether an object sinks or floats. This is illustrated in Figure below . |
Boiling points increase with which kind of mass? | protons mass | lipid mass | universal mass | molar mass | Carboxylic acids have high boiling points compared to other substances of comparable molar mass. Boiling points increase with molar mass. |
The largest absorption of heat comes during the vaporization of what? | magma | ice | carbon dioxide | liquid water | The total heat absorbed as the ice at -30°C is heated to steam at 140°C is 113.4 kJ. The largest absorption of heat comes during the vaporization of the liquid water. |
What do fungi absorb to get their nutrition? | soil | water | air | organic compounds from other organisms | Most fungi grow on moist soil or rotting vegetation such as dead logs. Some fungi live in water. Others live in or on other organisms. Fungi get their nutrition by absorbing organic compounds from other organisms. The other organisms may be dead or alive, depending on the fungus. |
The variable is the speed of light. for the relationship to hold mathematically, if the speed of light is used in m/s, the wavelength must be in meters and the frequency in what? | centimeters | gigawatts | miles | hertz | The variable is the speed of light. For the relationship to hold mathematically, if the speed of light is used in m/s, the wavelength must be in meters and the frequency in Hertz. |
A yolk sac replaces what structure for nourishing a marsupial embryo? | Stomach | uterus | glucose | placenta | The marsupial embryo is nourished inside the uterus with food from a yolk sac instead of through a placenta. The yolk sac stores enough food for the short period of time the embryo remains in the uterus. After the embryo is born, it moves into the mother’s pouch, where it clings to a nipple. It remains inside the pouch for several months while it continues to grow and develop. Even after the offspring is big enough to leave the pouch, it may often return to the pouch for warmth and nourishment ( Figure below ). Eventually, the offspring is mature enough to remain outside the pouch on its own. |
What is the pressure of gas in a gas mixture termed? | partial energy | gaseous energy | gaseous pressure | partial pressure | The pressure of a gas in a gas mixture is termed the partial pressure. |
Making ups about 50 percent of the modern american diet, what food group can be classified according to the number of monomers they contain of simple sugars and/or complex sugars? | grains | proteins | fats | carbohydrates | Carbohydrate Digestion The average American diet is about 50 percent carbohydrates, which may be classified according to the number of monomers they contain of simple sugars (monosaccharides and disaccharides) and/or complex sugars (polysaccharides). Glucose, galactose, and fructose are the three monosaccharides that are commonly consumed and are readily absorbed. Your digestive system is also able to break down the disaccharide sucrose (regular table sugar: glucose + fructose), lactose (milk sugar: glucose + galactose), and maltose (grain sugar: glucose + glucose), and the polysaccharides glycogen and starch (chains of monosaccharides). Your bodies do not produce enzymes that can break down most fibrous polysaccharides, such as cellulose. While indigestible polysaccharides do not provide any nutritional value, they do provide dietary fiber, which helps propel food through the alimentary canal. The chemical digestion of starches begins in the mouth and has been reviewed above. In the small intestine, pancreatic amylase does the ‘heavy lifting’ for starch and carbohydrate digestion (Figure 23.29). After amylases break down starch into smaller fragments, the brush border enzyme α-dextrinase starts working on αdextrin, breaking off one glucose unit at a time. Three brush border enzymes hydrolyze sucrose, lactose, and maltose into monosaccharides. Sucrase splits sucrose into one molecule of fructose and one molecule of glucose; maltase breaks down maltose and maltotriose into two and three glucose molecules, respectively; and lactase breaks down lactose into one molecule of glucose and one molecule of galactose. Insufficient lactase can lead to lactose intolerance. |
What is the process of the fusion of a sperm and an egg called? | stimulation | Sperm | embryo | fertilization | Fertilization The fusion of a sperm and an egg is a process called fertilization. This can occur either inside ( internal fertilization) or outside ( external fertilization) the body of the female. Humans provide an example of the former, whereas frog reproduction is an example of the latter. |
What is the motion that moves the forearm from the supinated position to the pronated position? | supination | extension | flexion | pronation | Supination and Pronation Supination and pronation are movements of the forearm. In the anatomical position, the upper limb is held next to the body with the palm facing forward. This is the supinated position of the forearm. In this position, the radius and ulna are parallel to each other. When the palm of the hand faces backward, the forearm is in the pronated position, and the radius and ulna form an X-shape. Supination and pronation are the movements of the forearm that go between these two positions. Pronation is the motion that moves the forearm from the supinated (anatomical) position to the pronated (palm backward) position. This motion is produced by rotation of the radius at the proximal radioulnar joint, accompanied by movement of the radius at the distal radioulnar joint. The proximal radioulnar joint is a pivot joint that allows for rotation of the head of the radius. Because of the slight curvature of the shaft of the radius, this rotation causes the distal end of the radius to cross over the distal ulna at. |
What organ system consists of the skin, nails and hair? | endocrine system | nervous system | digestive system | integumentary system | The skin is the major organ of the integumentary system , which also includes the nails and hair. In fact, the skin is the body’s largest organ, and a remarkable one at that. Consider these skin facts. The average square inch (6.5 cm 2 ) of skin has 20 blood vessels, 650 sweat glands, and more than a thousand nerve endings. It also has an incredible 60,000 pigment-producing cells. All of these structures are packed into a stack of cells that is just 2 mm thick, or about as thick as the cover of a book. |
What does it mean to be a diploid organism? | micelles have two copies of each gene | yolk has two copies of each gene | taproot has two copies of each gene | organism has two copies of each gene | Early land plants also evolved a dominant sporophyte generation. Sporophytes are diploid, so they have two copies of each gene. This gives them a "back-up" copy in case of mutation. This was important for coping with the strong solar radiation and higher risk of mutations on land. |
What do you call the carbohydrate formed when two monosaccharides bond together? | hydroxyl | calcite | glucose | disaccharide | If two monosaccharides bond together, they form a carbohydrate called a disaccharide . An example of a disaccharide is sucrose (table sugar), which consists of the monosaccharides glucose and fructose ( Figure above ). Monosaccharides and disaccharides are also called simple sugars . They provide the major source of energy to living cells. |
What is the term for a resource that is used in a way that meets the needs of the present without keeping future generations from meeting their needs? | structural | tolerable | innovative | sustainable | A resource is renewable if it is remade by natural processes at the same rate that humans use it up. Sunlight and wind are renewable resources because they will not be used up ( Figure below ). The rising and falling of ocean tides is another example of a resource in unlimited supply. A sustainable resource is a resource that is used in a way that meets the needs of the present without keeping future generations from meeting their needs. People can sustainably harvest wood, cork, and bamboo. Farmers can also grow crops sustainably by not planting the same crop in their soil year after year. Planting the same crop each year can remove nutrients from the soil. This means that wood, cork, bamboo, and crops can be sustainable resources. |
The genes that code for the positive cell cycle regulators are called what? | ribosomes | stem cell genes | primary genes | proto-oncogenes | Proto-oncogenes The genes that code for the positive cell cycle regulators are called proto-oncogenes. Proto-oncogenes are normal genes that, when mutated in certain ways, become oncogenes, genes that cause a cell to become cancerous. Consider what might happen to the cell cycle in a cell with a recently acquired oncogene. In most instances, the alteration of the DNA sequence will result in a less functional (or non-functional) protein. The result is detrimental to the cell and will likely prevent the cell from completing the cell cycle; however, the organism is not harmed because the mutation will not be carried forward. If a cell cannot reproduce, the mutation is not propagated and the damage is minimal. Occasionally, however, a gene mutation causes a change that increases the activity of a positive regulator. For example, a mutation that allows Cdk to be activated without being partnered with cyclin could push the cell cycle past a checkpoint before all of the required conditions are met. If the resulting daughter cells are too damaged to undergo further cell divisions, the mutation would not be propagated and no harm would come to the organism. However, if the atypical daughter cells are able to undergo further cell divisions, subsequent generations of cells will probably accumulate even more mutations, some possibly in additional genes that regulate the cell cycle. The Cdk gene in the above example is only one of many genes that are considered proto-oncogenes. In addition to the cell cycle regulatory proteins, any protein that influences the cycle can be altered in such a way as to override cell cycle checkpoints. An oncogene is any gene that, when altered, leads to an increase in the rate of cell cycle progression. |
What are essential for pollination, but can spread disease and destroy crops? | mice | fruits | spiders | insects | Insects spread disease and destroy crops. However, they are essential for pollinating flowering plants. |
Branching food chains and complex trophic interactions form what? | food trees | food fields | food maps | food webs | |
The chemical behavior of elements can largely be explained by what? | neutron configuration | chemical configuration | proton configuration | electron configurations | The chemical behavior of elements can largely be explained by electron configurations. |
Metalloids, metals, and nonmetals are all classes of what? | matter | compounds | protons | elements | Metalloids are the smallest class of elements. (The other two classes of elements are metals and nonmetals). There are just six metalloids. In addition to silicon, they include boron, germanium, arsenic, antimony, and tellurium. Metalloids fall between metals and nonmetals in the periodic table. They also fall between metals and nonmetals in terms of their properties. |
How does air always flow? | low to high | in to out | left to right | high to low | Cold air is dense, so it sinks. This creates a center of high pressure. Warm air is less dense so it rises. This creates a center of low pressure. Air always flows from higher to lower pressure. As the air flows, Earth’s surface rotates below it causing Coriolis effect. So while the wind blows into the low pressure, it revolves in a circular pattern. This wind pattern forms a cyclone. The same happens while the wind blows out of a high pressure. This forms an anticyclone. Both are shown in Figure below . |
What type of invisible waves are used in microwaves? | thermal | convection | electric | radiation | Did you ever wonder how a microwave works? It directs invisible waves of radiation toward the food placed inside of it. The radiation transfers energy to the food, causing it to get warmer. The radiation is in the form of microwaves, which are a type of electromagnetic waves. |
Which muscular organ pumps blood all around your body? | pancreas | stomach | lungs | heart | When you think of muscles, you might think of biceps and the external muscles you see in a bodybuilder. However, some muscles are found deep inside your body. The heart, for example, is a very muscular organ. It has to pump blood all around your body. |
What causes the changes of puberty? | testosterone | glucose | insulin | estrogen | During adolescence, estrogen causes the changes of puberty. It causes the reproductive organs to mature. It also causes other female traits to develop. For example, it causes the breasts to grow and the hips to widen. |
If a sedimentary rock layer is not horizontal, what is it? | igneous | striated | mineralized | deformed | Sedimentary rock layers that are not horizontal are deformed. |
What system, which includes the skin, plays important roles in protection, sensing stimuli and thermoregulation? | teleporters system | digestive system | pectins system | integumentary system | 5.3 Functions of the Integumentary System The skin plays important roles in protection, sensing stimuli, thermoregulation, and vitamin D synthesis. It is the first layer of defense to prevent dehydration, infection, and injury to the rest of the body. Sweat glands in the skin allow the skin surface to cool when the body gets overheated. Thermoregulation is also accomplished by the dilation or constriction of heat-carrying blood vessels in the skin. Immune cells present among the skin layers patrol the areas to keep them free of foreign materials. Fat stores in the hypodermis aid in both thermoregulation and protection. Finally, the skin plays a role in the synthesis of vitamin D, which is necessary for our well-being but not easily available in natural foods. |
What type of plant tissue transports water and dissolved mineral upward to the leaves? | phloem | collagen | ectoderm | xylem | Xylem carries water and dissolved minerals from the roots upward to the leaves. |
What can lenses be used to make? | comparison representations | aspect representations | function representations | visual representations | Lenses can be used to make visual representations, called images . |
Surface tension is a property of matter that is in what state? | Base | mixture | water | liquid | Molecules within a liquid are pulled equally in all directions by intermolecular forces. However, molecules at the surface are pulled downwards and sideways by other liquid molecules, but not upwards away from the surface. The overall effect is that the surface molecules are pulled into the liquid, creating a surface that is tightened like a film. This phenomenon is referred to as surface tension . Liquids that have strong intermolecular forces, like the hydrogen bonding in water, exhibit the greatest surface tension. Table below shows surface tension values for various common liquids. |
Amphibians have permeable skin which allows for the exchange of oxygen and carbon dioxide, what is this "breathing called?" | aquatic respiration | variant respiration | benign respiration | cutaneous respiration | Characteristics of Amphibians As tetrapods, most amphibians are characterized by four well-developed limbs. Some species of salamanders and all caecilians are functionally limbless; their limbs are vestigial. An important characteristic of extant amphibians is a moist, permeable skin that is achieved via mucus glands that keep the skin moist; thus, exchange of oxygen and carbon dioxide with the environment can take place through it ( cutaneous respiration). Additional characteristics of amphibians include pedicellate teeth—teeth in which the root and crown are calcified, separated by a zone of noncalcified tissue—and a papilla amphibiorum and papilla basilaris, structures of the inner ear that are sensitive to frequencies below and above 10,00 hertz, respectively. Amphibians also have an auricular operculum, which is an extra bone in the ear that transmits sounds to the inner ear. All extant adult amphibians are carnivorous, and some terrestrial amphibians have a sticky tongue that is used to capture prey. |
What is the main component of paper, cardboard, and textiles made from cotton, linen, and other plant fibers? | vascular tissue | pulp | cambium | cellulose | Cellulose is another polymer of glucose, consisting of anywhere from hundreds to over ten thousand monomers. It is the structural component of the cell walls of green plants and is the single most common organic molecule on Earth. Roughly 33% of all plant matter is cellulose. The linkage structure in cellulose is different than that of starch, and cellulose is indigestible except by a few microorganisms that live in the digestive tracts of cattle and termites. The figure below shows a triple strand of cellulose. There is no branching and the fibers adopt a very stiff rod-like structure with numerous hydrogen bonds between the fibers adding to its strength. Cellulose is the main component of paper, cardboard, and textiles made from cotton, linen, and other plant fibers. |
What theory explains the physical behavior of gases? | quantum theory of gases | thermodynamic theory of gases | relativity theory of gases | kinetic theory of gases | The physical behavior of gases is explained by the kinetic theory of gases. |
Only finished mrnas are exported from the nucleus to what? | electron | amino acids | cerebellum | cytoplasm | 9.3 Transcription In prokaryotes, mRNA synthesis is initiated at a promoter sequence on the DNA template. Elongation synthesizes new mRNA. Termination liberates the mRNA and occurs by mechanisms that stall the RNA polymerase and cause it to fall off the DNA template. Newly transcribed eukaryotic mRNAs are modified with a cap and a poly-A tail. These structures protect the mature mRNA from degradation and help export it from the nucleus. Eukaryotic mRNAs also undergo splicing, in which introns are removed and exons are reconnected with single-nucleotide accuracy. Only finished mRNAs are exported from the nucleus to the cytoplasm. |
What is the largest artery in the body called? | femoral | carotid | subclavian | aorta | Arteries are muscular blood vessels that carry blood away from the heart. They have thick walls that can withstand the pressure of blood being pumped by the heart. Arteries generally carry oxygen-rich blood. The largest artery is the aorta , which receives blood directly from the heart. |
What type of change has occurred when a copper penny changes color? | reactive change | contamination change | carbon change | chemical change | Some of these pennies are shiny and copper colored. That’s how pennies look when they are new. The older pennies are dull and brown. Copper at the surface of these pennies has combined with air to become a different substance with different properties. The change in color shows that a chemical change has occurred. |
A switch in a circuit controls the flow of what, specifically, within the circuit? | density | pressure | resistance | current | Many circuits have switches to control the flow of current through the circuit. When the switch is turned on, the circuit is closed and current can flow through it. When the switch is turned off, the circuit is open and current cannot flow through it. |
What causes fertilization to occur? | genetic and an egg fuse | accumulation and an egg fuse | tissue and an egg fuse | sperm and an egg fuse | Many animals have a relatively simple life cycle. A general animal life cycle is shown in Figure below . Most animals spend the majority of their life as diploid organisms. Just about all animals reproduce sexually. Diploid adults undergo meiosis to produce sperm or eggs. Fertilization occurs when a sperm and an egg fuse. The zygote that forms develops into an embryo. The embryo eventually develops into an adult. |
Because they spread seeds, fruits are an agent of what? | predation | propagation | disposal | dispersal | Fruit The seed forms in an ovary, which enlarges as the seeds grow. As the seed develops, the walls of the ovary also thicken and form the fruit. In botany, a fruit is a fertilized and fully grown, ripened ovary. Many foods commonly called vegetables are actually fruit. Eggplants, zucchini, string beans, and bell peppers are all technically fruit because they contain seeds and are derived from the thick ovary tissue. Acorns and winged maple keys, whose scientific name is a samara, are also fruit. Mature fruit can be described as fleshy or dry. Fleshy fruit include the familiar berries, peaches, apples, grapes, and tomatoes. Rice, wheat, and nuts are examples of dry fruit. Another distinction is that not all fruits are derived from the ovary. Some fruits are derived from separate ovaries in a single flower, such as the raspberry. Other fruits, such as the pineapple, form from clusters of flowers. Additionally, some fruits, like watermelon and orange, have rinds. Regardless of how they are formed, fruits are an agent of dispersal. The variety of shapes and characteristics reflect the mode of dispersal. The light, dry fruits of trees and dandelions are carried by the wind. Floating coconuts are transported by water. Some fruits are colored, perfumed, sweet, and nutritious to attract herbivores, which eat the fruit and disperse the tough undigested seeds in their feces. Other fruits have burs and hooks that cling to fur and hitch rides on animals. |
Proto-oncogenes normally help regulate what? | cell function | cell transition | cell death | cell division | |
The "double helix" shape is associated with what substance found in cells? | plasma | genes | bacteria | dna | data are passed to new generations; and even how proteins are built to required specifications. All these abilities depend on the pairing of complementary bases. Figure 19.7 "Complementary Base Pairing" shows the two sets of base pairs and illustrates two things. First, a pyrimidine is paired with a purine in each case, so that the long dimensions of both pairs are identical (1.08 nm). If two pyrimidines were paired or two purines were paired, the two pyrimidines would take up less space than a purine and a pyrimidine, and the two purines would take up more space, as illustrated in Figure 19.8 "Difference in Widths of Possible Base Pairs". If these pairings were ever to occur, the structure of DNA would be like a staircase made with stairs of different widths. For the two strands of the double helix to fit neatly, a pyrimidine must always be paired with a purine. The second thing you should notice in Figure 19.7 "Complementary Base Pairing" is that the correct pairing enables formation of three instances of hydrogen bonding between guanine and cytosine and two between adenine and thymine. The additive contribution of this hydrogen bonding imparts great stability to the DNA double helix. |
What do you call the physical environment in which a species lives and to which it is adapted? | ecosystem | domain | environment | habitat | An ecosystem consists of all the biotic and abiotic factors in an area and their interactions. A niche refers to the role of a species in its ecosystem. A habitat is the physical environment in which a species lives and to which it is adapted. Two different species cannot occupy the same niche in the same place for very long. |
What is the outer core made of? | solid iron | compressed air | solid rock | liquid metal | Yes! The outer core, anyway. The outer core is liquid metal, like in this photo. Of course, the metal is under an incredible amount of pressure. |
What type of eukaryotes are protists normally? | immature | multicellular | photosynthetic | unicellular | Most protists are so small that they can be seen only with a microscope. Protists are mostly unicellular (one-celled) eukaryotes. A few protists are multicellular (many-celled) and surprisingly large. For example, kelp is a multicellular protist that can grow to be over 100-meters long ( Figure below ). Multicellular protists, however, do not show cellular specialization or differentiation into tissues. That means their cells all look the same and, for the most part, function the same. On the other hand, your cells often are much different from each other and have special jobs. |
An inclined plane is a good example of what kind of machine? | weak | strong | complex | simple | An inclined plane is also a simple machine. The resistance is the weight of the box resting on the inclined plane. In order to lift this box straight up, the effort force would need to be equal to its weight. However, assuming no friction, less effort (a smaller effort force) is required to slide the box up the incline. We know this intuitively; when movng boxes into a truck or onto a platform, we use angled platforms instead of lifting it straight up. |
The pressure of a sample of gas is measured with an open-end what? | altimeter | thermometer | barometer | manometer | The pressure of a sample of gas is measured with an open-end manometer, partially shown to the right. The liquid in the manometer is mercury. Assuming atmospheric pressure is 29.92 in. Hg, determine the pressure of the gas in: (a) torr (b) Pa (c) bar. |
Bog destruction in scotland is an example of the widespread loss of what kind of habitat? | desert | tundra | ocean | wetland | A habitat that is quickly being destroyed is the wetland . By the 1980s, over 80% of all wetlands in parts of the U. S. were destroyed. In Europe, many wetland species have gone extinct. For example, many bogs in Scotland have been lost because of human development. |
What part of the plant has a root end and a shoot end? | pistol | radius | leaves | axis | |
Hardness, density, color, and melting and boiling points are all considered what types of properties? | thermal | chemical | visible | physical | Physical properties include color, density, hardness, and melting and boiling points. |
Low levels of thyroid hormones in the blood cause the release of what by the hypothalamus and pituitary gland? | enzymes | acids | bases | hormones | You can see an example of a negative feedback loop in Figure below . It shows how levels of thyroid hormones regulate the thyroid gland. This loop involves the hypothalamus and pituitary gland as well as the thyroid gland. Low levels of thyroid hormones in the blood cause the release of hormones by the hypothalamus and pituitary gland. These hormones stimulate the thyroid gland to secrete more hormones. The opposite happens with high levels of thyroid hormones in the blood. The hypothalamus and pituitary gland stop releasing hormones that stimulate the thyroid. |
The energy changes in what reactions are enormous compared with those of even the most energetic chemical reactions, and they result in a measurable change of mass? | methane combustion | molecular reaction | metabolic reaction | nuclear reactions | To understand the differences between nuclear fission and fusion. Nuclear reactions, like chemical reactions, are accompanied by changes in energy. The energy changes in nuclear reactions, however, are enormous compared with those of even the most energetic chemical reactions. In fact, the energy changes in a typical nuclear reaction are so large that they result in a measurable change of mass. In this section, we describe the relationship between mass and energy in nuclear reactions and show how the seemingly small changes in mass that accompany nuclear reactions result in the release of enormous amounts of energy. |
What type of chemistry is the study of the composition of matter? | symbolic | philosophical | reactive | analytical | Analytical chemistry is the study of the composition of matter. It focuses on separating, identifying, and quantifying chemicals in samples of matter. An analytical chemist may use complex instruments to analyze an unknown material in order to determine its various components. |
Scientists did not actually see viruses until what was invented? | telescope | magnifying glass | electronic scale | electron microscope | Scientists did not actually see viruses for the first time until the 1930s. That’s when the electron microscope was invented. The virus shown in Figure below was the first one to be seen. |
Regularly done aerobic activities can help build up endurance and make what vital organ stronger? | skin | stomach | brain | heart | Tim Wilson. Regularly done aerobic activities can help build up endurance and make the heart stronger . CC BY 2.0. |
What do all chemical sections need to get started? | pressure | speed | work | energy | The bonds between the atoms need to be rearranged. That is the definition of a chemical reaction. And all chemical sections need energy to get started. |
What do people apply to their lawns that causes water pollution? | water | seeds | manure | chemicals | People pollute water when they apply excess chemicals to their lawn. They may also dispose of pollutants incorrectly. |
What do vertebrates possess that is made up of repeating bony units? | spinal cord | notochord | skull | vertebral column | repeating bony units that make up the vertebral column of vertebrates. |
How long does it take for earth to rotate on it's axis one time? | 26 hours | 6 hours | 12 hours | 24 hours | Earth rotates on its axis every 24 hours. |
In what system can energy change forms but the total amount of energy stay constant? | heterogeneous | open | primary | closed | In a closed system, energy may change forms but the total amount of energy is constant. |
What characteristics of an organism help it survive? | Changes | systems | additions | adaptations | Some of the characteristics an organism has may help it survive. These characteristics are called adaptations . Some adaptations are better than others. |
The major component of a solution is called what? | water | solute | mixture | solvent | The major component of a solution is called the solvent. The minor component of a solution is called the solute. By major and minor we mean whichever component has the greater presence by mass or by moles. Sometimes this becomes confusing, especially with substances with very different molar masses. However, here we will confine the discussion to solutions for which the major component and the minor component are obvious. Solutions exist for every possible phase of the solute and the solvent. Salt water, for example, is a solution of solid NaCl in liquid water; soda water is a solution of gaseous CO2 in liquid water, while air is a solution of a gaseous solute (O2) in a gaseous solvent (N2). In all cases, however, the overall phase of the solution is the same phase as the solvent. |
What type of pollution is generated by power plants and factories that can directly raise the temperature of water? | variable pollution | atmospheric pollution | Space Pollution | thermal pollution | Thermal pollution raises the temperature of water. It is commonly caused by power plants and factories. The change in temperature can kill fish and other water organisms. |
Nearly all of what are constructed from a set of just 20 common amino acids? | complex proteins | artifical proteins | mammal proteins | biological proteins | Nearly all biological proteins are constructed from a set of just 20 common amino acids. The names, abbreviations, and other information for each of these amino acids are presented in the Table below . |
What takes place when water on earth’s surface changes to water vapor? | absorption | condensation | transpiration | evaporation | Evaporation takes place when water on Earth’s surface changes to water vapor. The sun heats the water and gives water molecules enough energy to escape into the atmosphere. Most evaporation occurs from the surface of the ocean. |
The muscles of the anterior neck assist in deglutition also known as what? | pulling | breathing | staring | swallowing | carbon atoms and the properties that result from that bonding. Hydrocarbons with only carbon-to-carbon single bonds (C–C) and existing as a continuous chain of carbon atoms also bonded to hydrogen atoms are called alkanes (or saturated hydrocarbons). Saturated, in this case, means that each carbon atom is bonded to four other atoms (hydrogen or carbon)—the most possible; there are no double or triple bonds in the molecules. |
Cells infected with viruses secrete what example of early induced proteins, which travel to adjacent cells and induce them to make antiviral proteins, a sacrifice that protects the surrounding cells? | metabolites | hormones | prokaryotes | interferons | Early induced Proteins Early induced proteins are those that are not constitutively present in the body, but are made as they are needed early during the innate immune response. Interferons are an example of early induced proteins. Cells infected with viruses secrete interferons that travel to adjacent cells and induce them to make antiviral proteins. Thus, even though the initial cell is sacrificed, the surrounding cells are protected. Other early induced proteins specific for bacterial cell wall components are mannose-binding protein and C-reactive protein, made in the liver, which bind specifically to polysaccharide components of the bacterial cell wall. Phagocytes such as macrophages have receptors for these proteins, and they are thus able to recognize them as they are bound to the bacteria. This brings the phagocyte and bacterium into close proximity and enhances the phagocytosis of the bacterium by the process known as opsonization. Opsonization is the tagging of a pathogen for phagocytosis by the binding of an antibody or an antimicrobial protein. |
What term is used to describe changes to an organism’s dna and are an important driver of diversity in populations? | evolutions | adaptations | pathogens | mutations | Mutation Mutations are changes to an organism’s DNA and are an important driver of diversity in populations. Species evolve because of the accumulation of mutations that occur over time. The appearance of new mutations is the most common way to introduce novel genotypic and phenotypic variance. Some mutations are unfavorable or harmful and are quickly eliminated from the population by natural selection. Others are beneficial and will spread through the population. Whether or not a mutation is beneficial or harmful is determined by whether it helps an organism survive to sexual maturity and reproduce. Some mutations do not do anything and can linger, unaffected by natural selection, in the genome. Some can have a dramatic effect on a gene and the resulting phenotype. |
Molecules with a carboxyl group are called what? | Fatty acids | acetic acids | catalyzed acids | carboxylic acids | Molecules with a carboxyl group are called carboxylic acids. As with aldehydes, the functional group in carboxylic acids is at the end of a carbon chain. Also as with aldehydes, the C atom in the functional group is counted as one of the C atoms that defines the parent hydrocarbon name. To name carboxylic acids, the parent name of the hydrocarbon is used, but the suffix -oic acid is added:. |
What type of galaxies have a rotating disk of stars and dust, a bulge in the middle, and several arms? | spherical galaxies | pinwheel galaxies | round galaxies | spiral galaxies | Spiral galaxies have a rotating disk of stars and dust, a bulge in the middle, and several arms spiraling out from the center. The disk and arms contain many young, blue stars. |
How is carbon dioxide and water vapor that is produced by cellular respiration released? | evaporation | peroxidation | fermentation | exhalation | A: Breathing consists of inhaling and exhaling, and its purpose is to move gases into and out of the body. Oxygen needed for cellular respiration is brought into the body with each inhalation. Carbon dioxide and water vapor produced by cellular respiration are released from the body with each exhalation. |
What occurs when there are differences in fitness among a population? | natural change | evolution | natural process | natural selection | Natural selection occurs when there are differences in fitness among members of a population. As a result, some individuals pass more genes to the next generation. This causes allele frequencies to change. |
A group of living things and their environment is called what? | biome | community | population | ecosystem | An ecosystem is a group of living things and their environment. The word ecosystem is short for “ecological system. ” Like any system, an ecosystem is a group of parts that work together. You can see examples of ecosystems in Figure below . The forest pictured is a big ecosystem. Besides trees, what living things do you think are part of the forest ecosystem? The dead tree stump in the same forest is a small ecosystem. It includes plants, mosses, and fungi. It also includes insects and worms. |
Iridescent green beetles, known as jewel beetles, change color because of the light-reflecting properties of the cells that make up this? | their scales | their hairs | their wings | their external skeleton | Each section contains a liquid crystal sample with a different liquid crystalline range. The section whose liquid crystalline range corresponds to the temperature of the body becomes translucent (here shown in green), indicating the temperature. We also see the effect of liquid crystals in nature. Iridescent green beetles, known as jewel beetles, change color because of the light-reflecting properties of the cells that make up their external skeletons, not because of light absorption from their pigment. The cells form helices with a structure like those found in cholesteric liquid crystals. When the pitch of the helix is close to the wavelength of visible light, the cells reflect light with wavelengths that lead to brilliant metallic colors. Because a color change occurs depending on a person’s angle of view, researchers in New Zealand are studying the beetles to develop a thin material that can be used as a currency security measure. The automobile industry is also interested in exploring such materials for use in paints that would change color at different viewing angles. With only molecular structure as a guide, one cannot precisely predict which of the various liquid crystalline phases a given compound will actually form. One can, however, identify molecules containing the kinds of structural features that tend to result in liquid crystalline behavior, as demonstrated in Example 11. |
The effects of which kind of selection are larger than the effects of direct natural selection on individuals? | unnatural selection | topical selection | stranger selection | kin selection | |
Superconductors are materials with a resistivity of? | high magnitude | above zero | greater density | zero | 34.6 High-temperature Superconductors Superconductors are materials with a resistivity of zero. They are familiar to the general public because of their practical applications and have been mentioned at a number of points in the text. Because the resistance of a piece of superconductor is zero, there are no heat losses for currents through them; they are used in magnets needing high currents, such as in MRI machines, and could cut energy losses in power transmission. But most superconductors must be cooled to temperatures only a few kelvin above absolute zero, a costly procedure limiting their practical applications. In the past decade, tremendous advances have been made in producing materials that become superconductors at relatively high temperatures. There is hope that room temperature superconductors may someday be manufactured. |
What affects how high a cake rises when it bakes? | current pressure | air currents | air movement | air pressure | Air pressure affects how high a cake rises when it bakes. Directions for cake mixes often have special high altitude instructions, like those on the label below. Explain why. |
Binary fission is an example of which type of production? | sexual | primitive | algal | asexual | Binary fission is a type of asexual reproduction. It occurs when a parent cell splits into two identical daughter cells. This can result in very rapid population growth. For example, under ideal conditions, bacterial populations can double every 20 minutes. Such rapid population growth is an adaptation to an unstable environment. Can you explain why?. |
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