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Lipids are biochemical compounds such as fats and? | minerals | filaments | negative forces | oils | Lipids are biochemical compounds such as fats and oils. Organisms use lipids to store energy. In addition to carbon and hydrogen, lipids contain oxygen. | chemistry | 1 |
What is the process of small molecules passing through the plasma membrane called? | convection | permeation | absorption | diffusion | Small molecules can pass through the plasma membrane through a process called diffusion. Diffusion is the movement of molecules from an area where there is a higher concentration (larger amount) of the substance to an area where there is a lower concentration (lower amount) of the substance ( Figure below ). The amount of a substance in relation to the total volume is the concentration . During diffusion, molecules are said to flow down their concentration gradient , flowing from an area of high concentration to an area of low concentration. Molecules flowing down a concentration gradient is a natural process and does not require energy. | chemistry | 3 |
What change the physical properties of solvents? | fact | second conservation law | cells | solutes | Solutes change the physical properties of solvents. They lower the freezing point and raise the boiling point of solvents. | physics | 1 |
Which human body system is a complex network of nervous tissue that carries electrical messages throughout the body? | photosynthetics | the localized system | the lymph system | the nervous system | The nervous system is a complex network of nervous tissue that carries electrical messages throughout the body. Its functions include controlling muscles, maintaining balance, sensing internal and external environments, controlling body systems to maintain homeostasis, preparing the body for emergencies, and allowing higher mental functions such as thinking. | biology | 2 |
What is a sheet of muscle that spreads across the bottom of the rib cage? | urinary | the core | they could conduct photosynthesis | diaphragm | The diaphragm is a sheet of muscle that spreads across the bottom of the rib cage. When the diaphragm contracts, the chest volume gets larger, and the lungs take in air. When the diaphragm relaxes, the chest volume gets smaller, and air is pushed out of the lungs. | biology | 0 |
What creates charged regions in a water molecule? | combustion reactions | Objects | martian iron | polar covalent bonds | chemistry | 0 |
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Phosphorus exists as several allotropes, the most common being red, black, and what? | purification | cones | circular hydrocarbon | white phosphorus | Phosphorus exists as several allotropes, the most common being red, black, and white phosphorus. White phosphorus consists of tetrahedral P4 molecules and melts at 44.15°C; it is converted to red phosphorus by heating at 400°C for several hours. The chemical differences between red and white phosphorus are considerable: white phosphorus burns in air, whereas red phosphorus is stable; white phosphorus is soluble in organic compounds, whereas red phosphorus is not; white phosphorus melts at 44.15°C, whereas red phosphorus melts at 597°C. If the enthalpy of fusion of white phosphorus is 0.659 kJ/mol, what is its ΔS? Black phosphorus is even less reactive than red. Based on this information, which allotrope would you predict to have the highest entropy? the lowest? Why?. | chemistry | 0 |
What is the term for environmental causes of mutations? | .175 million years | Dengue fever | catalysts | mutagens | A mutation is a change in the base sequence of DNA or RNA. Environmental causes of mutations are called mutagens. The effects of a mutation depend on the type of mutation and whether it occurs in a gamete or body cell. | biology | 1 |
How are classic sedimentary rocks group? | when they melt | particle depth | mid-atlantic ridge | size of sediment | Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. | geography | 1 |
How many eyelid membranes do frogs have? | one | two | four | three | In order to live on land and in water, frogs have three eyelid membranes: one is see-through to protect the eyes underwater, and the two other ones let them see on land. Frogs also have a tympanum , which acts like a simple ear. They are found on each side of the head. In some species, the tympanum is covered by skin. | biology | 3 |
What is another word for saturated hydrocarbons? | nitrogen and oxygen | two actin chains | resonance | alkanes | Saturated hydrocarbons contain only single bonds between carbon atoms. They are also called alkanes. They may form straight-chain, branched-chain, or cyclic molecules. Compounds with the same number of atoms but different shapes are called isomers. | chemistry | 0 |
Where is the pressure of gases in the atmosphere at its greatest? | venn diagram | compromised cells | excessive | sea level | The pressure of gases in the atmosphere is greatest at sea level and decreases rapidly as altitude increases. | geography | 2 |
What strong and lightweight manmade material is derived from hydrocarbons and used in ropes, tents and parachutes? | Brain Cells | a parabola | glacier | nylon | nylon: Human-made fabric. Material is made from hydrocarbons found in petroleum products. It is found in a number of plastic utensils. Taking advantages of its strength and light weight, nylon is a component of ropes, fishing nets, tents, and parachutes. | physics | 1 |
What is the third male reprodutive structure after the penis and testes? | mechanically | clitoris | inductive reasoning | epididymis | Male reproductive structures include the penis, testes, and epididymis. | biology | 2 |
What are considered solid lipids that animals use to store energy? | proteins | acids | cervical | fats | Fats are solid lipids that animals use to store energy. Examples of fats include butter and the fat in meat. | biology | 2 |
The small, egg-shaped organs that lie on either side of the uterus are called? | neutral | eat | glands | ovaries | The two ovaries are small, egg-shaped organs that lie on either side of the uterus. They produce eggs and secrete estrogen. Each egg is located inside a structure called a follicle . Cells in the follicle protect the egg and help it mature. | biology | 2 |
Which competition leads to one species going extinct or both becoming more specialized? | the brain | 17 pairs | large blood cells | interspecific | Interspecific competition occurs between members of different species. It may lead to one species going extinct or both becoming more specialized. | biology | 0 |
Who discovered that the andromeda nebula is over 2 million light years away | it is slow | natural energy | electrical charge | edwin hubble | The universe contains all the matter and energy that exists and all of space and time. We are always learning more about the universe. In the early 20th century, Edwin Hubble used powerful telescopes to show that some distant specks of light seen through telescopes are actually other galaxies. ( Figure below ) Hubble discovered that the Andromeda Nebula is over 2 million light years away. This is many times farther than the farthest distances we had measured before. He realized that galaxies were collections of millions or billions of stars. Hubble also measured the distances to hundreds of galaxies. Today, we know that the universe contains about a hundred billion galaxies. | physics | 0 |
What does every star emit that humans cannot see? | intermolecular gravitational forces | tidal | a lever | radiation | Visible light is only a small part of the electromagnetic spectrum. There are parts of the electromagnetic spectrum that humans cannot see. This radiation exists all around you. You just can’t see it! Every star, including our Sun, emits radiation of many wavelengths. Astronomers can learn a lot from studying the details of the spectrum of radiation from a star. | physics | 0 |
What type pf mining is used to obtain mineral ores that are near the surface? | core mining | excretory system | gravitational indication energy | surface mining | Surface mining is used to obtain mineral ores that are near the surface. Blasting breaks up the soil and rocks that contain the ore. Enormous trucks haul the broken rocks to locations where the ores can be removed. Surface mining includes open-pit mining, quarrying, and strip mining. | physics | 1 |
The external female reproductive structures are referred to collectively as what? | wing flapping | fertilizer plants | five | the vulva | The external female reproductive structures are referred to collectively as the vulva. They include the labia (singular, labium), which are the “lips” of the vulva. The labia protect the vagina and urethra, both of which have openings in the vulva. | biology | 0 |
Acid rain may be caused by what? | volcanos | greedy reactions | a liquid | air pollution | Air pollution may also cause acid rain. This is rain that is more acidic (has a lower pH) than normal rain. Acids form in the atmosphere when nitrogen and sulfur oxides mix with water in air. Nitrogen and sulfur oxides come mainly from motor vehicle exhaust and coal burning. | chemistry | 1 |
What process is used to chemically and mechanically break down the food you eat into smaller parts? | membrane energy | phospholipids | acidity | digestion | Digestion and Absorption Digestion is the mechanical and chemical break down of food into small organic fragments. It is important to break down macromolecules into smaller fragments that are of suitable size for absorption across the digestive epithelium. Large, complex molecules of proteins, polysaccharides, and lipids must be reduced to simpler particles such as simple sugar before they can be absorbed by the digestive epithelial cells. Different organs play specific roles in the digestive process. | chemistry | 0 |
What is the study of matter and the changes that material substances undergo. | moons | wrap | ionosphere | chemistry | Chemistry is the study of matter and the changes that material substances undergo. Of all the scientific disciplines, it is perhaps the most extensively connected to other fields of study. Geologists who want to locate new mineral or oil deposits use chemical techniques to analyze and identify rock samples. Oceanographers use chemistry to track ocean currents, determine the flux of nutrients into the sea, and measure the rate of exchange of nutrients between ocean layers. Engineers consider the relationships between the structures and the properties of substances when they specify materials for various uses. Physicists take advantage of the properties of substances to detect new subatomic particles. Astronomers use chemical signatures to determine the age and distance of stars and thus answer questions about how stars form and how old the universe is. The entire subject of environmental science depends on chemistry to explain the origin and impacts of phenomena such as air pollution, ozone layer depletion, and global warming. The disciplines that focus on living organisms and their interactions with the physical world rely heavily on biochemistry, the application of chemistry to the study of biological processes. A living cell contains a large collection of complex molecules that carry out thousands of chemical reactions, including those that are necessary for. | physics | 0 |
What occurs when the presence or absence of a specific behavior prevents reproduction from taking place? | diverse libraries | andronisis | before the pollen tube | behavioral isolation | Behavioral isolation occurs when the presence or absence of a specific behavior prevents reproduction from taking place. For example, male fireflies use specific light patterns to attract females. Various species of fireflies display their lights differently. If a male of one species tried to attract the female of another, she would not recognize the light pattern and would not mate with the male. Other prezygotic barriers work when differences in their gamete cells (eggs and sperm) prevent fertilization from taking place; this is called a gametic barrier. Similarly, in some cases closely related organisms try to mate, but their reproductive structures simply do not fit together. For example, damselfly males of different species have differently shaped reproductive organs. If one species tries to mate with the female of another, their body parts simply do not fit together. (Figure 18.19). | biology | 0 |
Why have rivers in arid regions been reduced to trickles? | emigration | global warming | rainforest destruction | diversion of water | geography | 3 |
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Having extra chromosomes or damaged chromosomes can cause what? | shed their petals | temperature | sporophytes | disorders | Some children are born with genetic defects that are not carried by a single gene. Instead, an error in a larger part of the chromosome or even in an entire chromosome causes the disorder. Usually the error happens when the egg or sperm is forming. Having extra chromosomes or damaged chromosomes can cause disorders. | biology | 0 |
What do farmers use greenhouses for? | reproductive spasms | enriched molecules | to allow the growing season | to extend the growing season | Farmers use greenhouses to extend the growing season. A greenhouse traps heat. Days that are too cool for a growing plant can be made to be just right. Similar to a greenhouse, greenhouse gases in the atmosphere keep Earth warm. | biology | 2 |
What is it called when two waves in the same medium pass one another? | uniform | nature and purpose | mean zero | interference | Any two waves in the same medium undergo wave interference as they pass each other. At the location where the two waves collide, the result is essentially a summation of the two waves. In some places, a wave crest from one source will overlap a wave crest from the other source. Since both waves are lifting the medium, the combined wave crest will be twice as high as the original crests. Nearby, a wave trough will overlap another wave trough and the new trough will be twice as deep as the original. This is called constructive interference because the resultant wave is larger than the original waves. Within the interference pattern, the amplitude will be twice the original amplitude. Once the waves pass through each other and are alone again, their amplitudes return to their original values. | physics | 1 |
Which forests are found throughout the ocean in temperate and arctic climates? | cedar | magnetic north pole | soil scientists | kelp | Multicellular seaweeds called kelp may grow as large as trees. They are the food base of ecosystems called kelp forests (see Figure below ). Kelp forests are found throughout the ocean in temperate and arctic climates. They are highly productive ecosystems. | geography | 3 |
What is the type of cancer in which bone marrow produces abnormal white blood cells that cannot fight infections? | they dominate | lymphedema | dna vesicles | leukemia | type of cancer in which bone marrow produces abnormal white blood cells that cannot fight infections. | biology | 1 |
Mechanical energy can also usually be expressed as the sum of kinetic energy and what other kind of energy? | partial energy | internal | magma eruption | potential energy | Kinetic and potential energy add up to mechanical energy. | physics | 2 |
What kind of bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them? | ionized bonds | neutron bonds | addition and multiplication | metallic bonds | Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure below ). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. For an animated version of metallic bonding, go to this URL:. | physics | 3 |
Aldehydes and ketones can work weak hydrogen bonds with water through what atom? | hydrogen dichromate | solid , mixture , gas | alkane | carbonyl oxygen atom | Aldehydes and ketones can work weak hydrogen bonds with water through the carbonyl oxygen atom. The lower members of both series (3 carbons or fewer) are soluble in water in all proportions. As the length of the carbon chain increases, water solubility decreases. Similar to ethers, neither aldehydes nor ketones can hydrogen bond with themselves. As a result, their boiling points are generally lower than those of alcohols. Unlike alkanes however, aldehydes and ketones are polar molecules due to the more electronegative oxygen atom. The dipole-dipole interactions are stronger than the dispersion forces present in alkanes. The boiling points of aldehydes and ketones are intermediate between those of alkanes and alcohols. For example, the boiling point of ethane is -89°C, ethanal is 20°C, and ethanol is 78°C. | chemistry | 1 |
Asexual reproduction in plants is typically an extension of the capacity for what? | blooming growth | extracellular growth | preferentially | indeterminate growth | biology | 3 |
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A type of what in a cow's gut enables the animal to digest grass? | a capsule | virus | reproductive cycle | bacteria | Kevin Walsh. Cows are able to digest grass with the help of the bacteria methanogens in their gut . CC BY 2.0. | biology | 1 |
What basic structures are called the building blocks of life and comprise all living things? | third stage | female reproductive system | Table Salt | cells | Cells may be small in size, but they are extremely important to life. Like all other living things, you are made of cells. Cells are the basis of life, and without cells, life as we know it would not exist. You will learn more about these amazing building blocks of life when you read this chapter. | biology | 0 |
What kind of behavior occurs only after experience or practice and describes most human behaviors? | practiced behavior | innate behavior | innate | learned behavior | Other than infant reflexes, human behaviors are mainly learned rather than innate behaviors. Learned behavior is behavior that occurs only after experience or practice. Did you ever teach a dog to sit on command? That’s an example of a learned behavior. The dog wasn’t born knowing that it should sit when it hears the word sit. The dog had to learn the behavior. | biology | 2 |
What is the study of the interaction between matter and energy called? | geology | astronomy | climatology | chemistry | Chemistry is the study of matter and energy and how they interact, mainly at the level of atoms and molecules. Basic concepts in chemistry include chemicals, which are specific types of matter, and chemical reactions. In a chemical reaction, atoms or molecules of certain types of matter combine chemically to form other types of matter. All chemical reactions involve energy. | physics | 3 |
Prescribed to treat allergies, antihistamines and corticosteroids help control what system that attacks allergens? | nervous system | allergies | slow it down | immune system | Most allergies can be treated with medicines. Medicines used to treat allergies include antihistamines and corticosteroids. These medicines help control the immune system when it attacks an allergen. Sometimes, allergies cause severe symptoms, a condition known as anaphylaxis. For example, they may cause the throat to swell so it is hard to breathe. Severe allergies may be life threatening. They require emergency medical care. | biology | 2 |
The main advantage of urea is its very low what? | barbiturate | reduction | voltage | toxicity | chemistry | 0 |
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What type of blood cells transport oxygen to the tissues so they can function? | depleted blood cells | white blood cells | motoric muscles | red blood cells | Red blood cells transport oxygen to the tissues so they can function. In the absence of oxygen, cells cannot carry out their biochemical responsibilities. Oxygen moves to the cells attached to hemoglobin, a protein found in the red cells. In cases of carbon monoxide poisoning, CO binds much more strongly to the hemoglobin, blocking oxygen attachment and lowering the amount of oxygen reaching the cells. Treatment involves the patient breathing pure oxygen to displace the carbon monoxide. The equilibrium reaction shown below illustrates the shift toward the right when excess oxygen is added to the system:. | biology | 3 |
What title is used to describe health professionals who use nonsurgical techniques to help patients with musculoskeletal system problems that involve the bones, muscles, ligaments, tendons, or nervous system? | priebus | pipes | rod protein | chiropractor chiropractors | Chiropractor Chiropractors are health professionals who use nonsurgical techniques to help patients with musculoskeletal system problems that involve the bones, muscles, ligaments, tendons, or nervous system. They treat problems such as neck pain, back pain, joint pain, or headaches. Chiropractors focus on the patient’s overall health and can also provide counseling related to lifestyle issues, such as diet, exercise, or sleep problems. If needed, they will refer the patient to other medical specialists. Chiropractors use a drug-free, hands-on approach for patient diagnosis and treatment. They will perform a physical exam, assess the patient’s posture and spine, and may perform additional diagnostic tests, including taking X-ray images. They primarily use manual techniques, such as spinal manipulation, to adjust the patient’s spine or other joints. They can recommend therapeutic or rehabilitative exercises, and some also include acupuncture, massage therapy, or ultrasound as part of the treatment program. In addition to those in general practice, some chiropractors specialize in sport injuries, neurology, orthopaedics, pediatrics, nutrition, internal disorders, or diagnostic imaging. To become a chiropractor, students must have 3–4 years of undergraduate education, attend an accredited, four-year Doctor of Chiropractic (D. ) degree program, and pass a licensure examination to be licensed for practice in their state. With the aging of the baby-boom generation, employment for chiropractors is expected to increase. | biology | 1 |
Flowers pollinated by what means generally lack brightly colored parts? | blue whale | single-celled prokaryotic | chemical spill | wind | biology | 2 |
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Fog disappears when the water droplets change back to what? | kenetic force | the base | positive ion | water vapor | The water droplets of fog form from water vapor in the air. Fog disappears when the water droplets change back to water vapor. These changes are examples of changes of state. A change of state occurs whenever matter changes from one state to another. Common states of matter on Earth are solid, liquid, and gas. Matter may change back and forth between any two of these states. | physics | 0 |
What is the name of the type of combustion engine that you would find in a car? | structure | outer space | Potential energy | internal combustion engine | A combustion engine is a complex machine that burns fuel to produce thermal energy and then uses the energy to do work. In a car, the engine does the work of providing kinetic energy that turns the wheels. The combustion engine in a car is a type of engine called an internal combustion engine. (Another type of combustion engine is an external combustion engine. ). | physics | 0 |
What must molecules have to be cis-trans isomers? | conductive substitution reactions | minerals must be created naturally | singularity | double bond | Which of the following statements is false? a. Molecules with the formulas CH3CH2COOH and C3H6O2 could be structural isomers. Molecules must have a double bond to be cis-trans isomers. To be enantiomers, a molecule must have at least three different atoms or groups connected to a central carbon. To be enantiomers, a molecule must have at least four different atoms or groups connected to a central carbon. In triglycerides (fats and oils), long carbon chains known as fatty acids may contain double bonds, which can be in either the cis or trans configuration, illustrated in Figure 2.25. Fats with at least one double bond between carbon atoms are unsaturated fats. When some of these bonds are in the cis configuration, the resulting bend in the carbon backbone of the chain means that triglyceride molecules cannot pack tightly, so they remain liquid (oil) at room temperature. On the other hand, triglycerides with trans double bonds (popularly called trans fats), have relatively linear fatty acids that are able to. | chemistry | 3 |
In physics, work means the use of what to move an object? | methane gas | mass | electronegativity | force | Work is defined differently in physics than in everyday language. In physics, work means the use of force to move an object. The teens who are playing basketball in the picture above are using force to move their bodies and the basketball, so they are doing work. The teen who is studying isn’t moving anything, so she isn’t doing work. Not all force that is used to move an object does work. For work to be done, the force must be applied in the same direction that the object moves. If a force is applied in a different direction than the object moves, no work is done. The Figure below illustrates this point. | physics | 2 |
Types of radiation that cause cancer include ultraviolet (uv) radiation and what? | a photograph | their polarities | chemical bonds | radon | Types of radiation that cause cancer include ultraviolet (UV) radiation and radon. UV radiation is part of sunlight. It is the leading cause of skin cancer. Radon is a naturally occurring radioactive gas that escapes from underground rocks. It may seep into the basements of buildings. It can cause lung cancer. | physics | 0 |
How many calories of energy does one gram of sugar or starch provide? | solubility increases | oxygen oxide | blindness and astigmatism | 4 | Carbohydrates include sugars, starches, and fiber. Sugars and starches are used by the body for energy. One gram of sugar or starch provides 4 Calories of energy. Fiber doesn’t provide energy, but it is needed for other uses. At age 13 years, you need about 130 grams of carbohydrates a day. Figure below shows good food sources of each type. | physics | 1 |
Defecating, urination, and even childbirth involve cooperation between the diaphragm and these? | carniverous | maladaptive trait | pineal glands | abdominal muscles | Defecating, urination, and even childbirth involve cooperation between the diaphragm and abdominal muscles (this cooperation is referred to as the “Valsalva maneuver”). You hold your breath by a steady contraction of the diaphragm; this stabilizes the volume and pressure of the peritoneal cavity. When the abdominal muscles contract, the pressure cannot push the diaphragm up, so it increases pressure on the intestinal tract (defecation), urinary tract (urination), or reproductive tract (childbirth). The inferior surface of the pericardial sac and the inferior surfaces of the pleural membranes (parietal pleura) fuse onto the central tendon of the diaphragm. To the sides of the tendon are the skeletal muscle portions of the diaphragm, which insert into the tendon while having a number of origins including the xiphoid process of the sternum anteriorly, the inferior six ribs and their cartilages laterally, and the lumbar vertebrae and 12th ribs posteriorly. The diaphragm also includes three openings for the passage of structures between the thorax and the abdomen. The inferior vena cava passes through the caval opening, and the esophagus and attached nerves pass through the esophageal hiatus. The aorta, thoracic duct, and azygous vein pass through the aortic hiatus of the posterior diaphragm. | biology | 0 |
When we move down a group of elements on the periodic table, what happens to their electronegativity? | intensity | skeletal | quickly then slowly | it decreases | The nonmetals are elements located in the upper right portion of the periodic table. Their properties and behavior are quite different from those of metals on the left side. Under normal conditions, more than half of the nonmetals are gases, one is a liquid, and the rest include some of the softest and hardest of solids. The nonmetals exhibit a rich variety of chemical behaviors. They include the most reactive and least reactive of elements, and they form many different ionic and covalent compounds. This section presents an overview of the properties and chemical behaviors of the nonmetals, as well as the chemistry of specific elements. Many of these nonmetals are important in biological systems. In many cases, trends in electronegativity enable us to predict the type of bonding and the physical states in compounds involving the nonmetals. We know that electronegativity decreases as we move down a given group and increases as we move from left to right across a period. The nonmetals have higher electronegativities than do metals, and compounds formed between metals and nonmetals are generally ionic in nature because of the large differences in electronegativity between them. The metals form cations, the nonmetals form anions, and the resulting compounds are solids under normal conditions. On the other hand, compounds formed between two or more nonmetals have small differences in electronegativity between the atoms, and covalent bonding—sharing of electrons—results. These substances tend to be molecular in nature and are gases, liquids, or volatile solids at room temperature and pressure. In normal chemical processes, nonmetals do not form monatomic positive ions (cations) because their ionization energies are too high. All monatomic nonmetal ions are anions; examples include the chloride ion, Cl−, the nitride ion, N3−, and the selenide ion, Se2−. The common oxidation states that the nonmetals exhibit in their ionic and covalent compounds are shown in Figure 18.19. Remember that an element exhibits a positive oxidation state when combined with a more electronegative element and that it exhibits a negative oxidation state when combined with a less electronegative element. | physics | 0 |
What two elements do chloroplasts split water into? | sodiums | solute and solvent | metalloid | hydrogen and oxygen | chemistry | 1 |
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Continuous-flow reactors are chemical reaction vessels in which the what are mixed and allowed to react as they flow along a tube? | photic and aphotic | increased | graphite | reactants | ♦ Many industrial processes for preparing compounds use “continuous-flow reactors,” which are chemical reaction vessels in which the reactants are mixed and allowed to react as they flow along a tube. The products are removed at a certain distance from the starting point, when the reaction is nearly complete. The key operating parameters in a continuous-flow reactor are temperature, reactor volume, and reactant flow rate. As an industrial chemist, you think you have successfully modified a particular process to produce a higher product yield by substituting one reactant for another. The viscosity of the new reactant is, however, greater than that of the initial reactant. | chemistry | 0 |
What is it called when one or more ending digits are dropped to get the correct number of significant figures? | bluehouse gases | renewable | thunderstorms | rounding | Rounding is done when one or more ending digits are dropped to get the correct number of significant figures. Simple rules state when to round up and when to round down. | physics | 2 |
Hair sticks out from the epidermis, but it grows from the? | mesozoic | survival selection | pinworms | dermis | Hair is one of the defining characteristics of mammals. In fact, mammals are the only animals to have hair. Hair sticks out from the epidermis, but it grows from the dermis ( Figure below ). Hair grows from inside the hair follicle . New cells grow in the bottom part of the hair, called the bulb. Older cells get pushed up, and the hair grows longer. The cells that make up the hair strand are dead and filled with the rope-like protein keratin. | biology | 2 |
The milky way galaxy is which shape type of galaxy? | 1938 | somatic nervous system | fans | spiral | The Milky Way Galaxy is a spiral galaxy that contains about 400 billion stars. Like other spiral galaxies, it has a disk, a central bulge, and spiral arms. The disk is about 100,000 light-years across. It is about 3,000 light years thick. Most of the galaxy’s gas, dust, young stars, and open clusters are in the disk. Some astronomers think that there is a gigantic black hole at the center of the galaxy. Figure below shows what the Milky Way probably looks like from the outside. | physics | 1 |
Atmospheric pressure is low in what anatomically named part of a hurricane? | smoke and ash | leg | whole earth | eye | Atmospheric pressure is low in the eye of a hurricane. In a 1979 hurricane in the Pacific Ocean, a pressure of 0.859 atm was reported inside the eye. What is this pressure in torr?. | geography | 1 |
What occurs when a substance diffuses through a cell membrane without any help from other molecules? | tendon | main generation | chemical resources | simple diffusion | Simple diffusion occurs when a substance diffuses through a cell membrane without any help from other molecules. The substance simply passes through tiny spaces in the membrane. It moves from the side of the membrane where it is more concentrated to the side where it is less concentrated. You can see how this happens in Figure below . | biology | 1 |
Sodium and chloride ions have equal but what charges? | ammonia | positive and charged | covalence electrons | opposite | Sodium and chloride ions have equal but opposite charges. Opposite electric charges attract each other, so sodium and chloride ions cling together in a strong ionic bond. You can see this in row 2 of the Figure above . (Brackets separate the ions in the diagram to show that the ions in the compound do not actually share electrons. ) When ionic bonds hold ions together, they form an ionic compound. The compound formed from sodium and chloride ions is named sodium chloride. It is commonly called table salt. You can see an animation of sodium chloride forming at this URL: http://www. visionlearning. com/library/module_viewer. php?mid=55. | chemistry | 3 |
What is making measurements that are close to the true value known as? | incomplete | string theory | changing brightness | accuracy | Accuracy means making measurements that are close to the true value. | physics | 0 |
What are muscle cells in the muscles called? | volvox | creationism | boric | muscle fibers | The muscular system consists of all the muscles of the body. Muscles are organs composed mainly of muscle cells, which are also called muscle fibers . Each muscle fiber is a very long, thin cell that can do something no other cell can do. It can contract, or shorten. Muscle contractions are responsible for virtually all the movements of the body, both inside and out. There are three types of muscle tissues in the human body: cardiac, smooth, and skeletal muscle tissues. They are shown in Figure below and described below. | biology | 0 |
What term means the minimum energy required in order for a collision between molecules to result in a chemical reaction? | copper alloy | electrical | solar energy | activation energy | Summary A minimum energy (activation energy, Ea) is required for a collision between molecules to result in a chemical reaction. Plots of potential energy for a system versus the reaction coordinate show an energy barrier that must be overcome for the reaction to occur. The arrangement of atoms at the highest point of this barrier is the activated complex, or transition state, of the reaction. At a given temperature, the higher the Ea, the slower the reaction. The fraction of orientations that result in a reaction is the steric factor. The frequency factor, steric factor, and activation energy are related to the rate constant in the Arrhenius equation: k = Ae - Ea / RT. A plot of the natural logarithm of k versus 1/T is a straight line with a slope of −Ea/R. Saylor URL: http://www. saylor. org/books. | chemistry | 3 |
What term is used to describe the change in size or volume of a given mass with temperature? | platinum | two electrons | detectable | thermal expansion | The expansion of alcohol in a thermometer is one of many commonly encountered examples of thermal expansion, the change in size or volume of a given mass with temperature. Hot air rises because its volume increases, which causes the hot air’s density to be smaller than the density of surrounding air, causing a buoyant (upward) force on the hot air. The same happens in all liquids and gases, driving natural heat transfer upwards in homes, oceans, and weather systems. Solids also undergo thermal expansion. Railroad tracks and bridges, for example, have expansion joints to allow them to freely expand and contract with temperature changes. What are the basic properties of thermal expansion? First, thermal expansion is clearly related to temperature change. The greater the temperature change, the more a bimetallic strip will bend. Second, it depends on the material. In a thermometer, for example, the expansion of alcohol is much greater than the expansion of the glass containing it. What is the underlying cause of thermal expansion? As is discussed in Kinetic Theory: Atomic and Molecular Explanation of Pressure and Temperature, an increase in temperature implies an increase in the kinetic energy of the individual atoms. In a solid, unlike in a gas, the atoms or molecules are closely packed together, but their kinetic energy (in the form of small, rapid vibrations) pushes neighboring atoms or molecules apart from each other. This neighbor-to-neighbor pushing results in a slightly greater distance, on average, between neighbors, and adds up to a larger size for the whole body. For most substances under ordinary conditions, there is no preferred direction, and an increase in temperature will increase the solid’s size by a certain fraction in each dimension. Linear Thermal Expansion—Thermal Expansion in One Dimension The change in length ΔL is proportional to length and length is summarized in the equation. | physics | 0 |
What are created based upon the loss or gain of electrons? | particle field | transferable heat | solute mass | ions | Christopher Auyeung. Ions are created by the loss or gain of electrons . CC BY-NC 3.0. | physics | 0 |
All atoms of the same element have the same number of what? | by dividing its volume by its mass | estimation | pole induction | protons | Atomic Number In the 1910s, experiments with X rays led to this useful conclusion: the magnitude of the positive charge in the nucleus of every atom of a particular element is the same. In other words, all atoms of the same element have the same number of protons. Furthermore,. | physics | 0 |
What kind of chain is formed by subduction of oceanic crust beneath a continental or oceanic plate? | nitrogen, carbon dioxide | repulsive | tsunami | volcano | Subduction of oceanic crust beneath a continental or oceanic plate creates a chain of volcanoes. | physics | 1 |
Which kinds of cells have nuclei and other membrane bound organelles? | fetal | arthritis | lipase | eukaryotes | Like the cells of all eukaryotes, animal cells have a nucleus and other membrane-bound organelles. Unlike the cells of eukaryotes in the Plant and Fungus Kingdoms, animal cells lack a cell wall. This gives animal cells flexibility. It lets them take on different shapes. This in turn allows them to become specialized for particular jobs. | biology | 0 |
What regulates the thyroid gland in a body? | ancient record | island symbolic model | gall bladder | negative feedback loop | The thyroid gland is regulated by a negative feedback loop. The loop includes the hypothalamus and pituitary gland in addition to the thyroid. | biology | 1 |
Females of what mammalian group have mammary glands but lack nipples? | inherited trait | Anthroponosis | ingestion, reproduction, absorption, and elimination | monotreme | Monotreme eggs have a leathery shell, like the eggs of reptiles. The eggs are retained inside the mother’s body for at least a couple of weeks. During that time, the mother provides the eggs with nutrients. Platypus females lay their eggs in a burrow. Echidna females have a pouch in which they store their eggs. Female monotremes have mammary glands but lack nipples. Instead, they “sweat” milk from a patch on their belly. | biology | 0 |
What helps fungus digest cellulose and other materials found in rotting matter? | nasal system | vascular disorders | bone | enzymes | Hyphae : These are thread-like strands which interconnect and bunch up into a mycelium ( Figure below ). Ever see mold on a damp wall or on old bread? The things that you are seeing are really mycelia. The hyphae and mycelia help the fungi absorb nutrients from other organisms. Most of the mycelium is hidden from view deep within the fungal food source, such as rotting matter in the soil, leaf litter, rotting wood, or dead animals. Fungi produce enzymes to digest cellulose and various other materials found in rotting matter, helping with the decaying process. | biology | 1 |
In what form of lipids cells store energy for long-term use? | treasure | meat | too much only | fat | Lipids Lipids include a diverse group of compounds that are united by a common feature. Lipids are hydrophobic (“waterfearing”), or insoluble in water, because they are nonpolar molecules. This is because they are hydrocarbons that include only nonpolar carbon-carbon or carbon-hydrogen bonds. Lipids perform many different functions in a cell. Cells store energy for long-term use in the form of lipids called fats. Lipids also provide insulation from the environment for plants and animals (Figure 2.17). For example, they help keep aquatic birds and mammals dry because of their water-repelling nature. Lipids are also the building blocks of many hormones and are an important constituent of the plasma membrane. Lipids include fats, oils, waxes, phospholipids, and steroids. | biology | 3 |
What is used to fluoridate drinking water to promote dental health | carbon fluorine | carbon fluoride | fragments | calcium fluoride | Calcium fluoride is used to fluoridate drinking water to promote dental health. Crystalline CaF 2 (d = 3.1805 3. | physics | 2 |
Light reactions also release oxygen gas as a what? | strange process | cosmology | formal process | waste product | The light reactions also release oxygen gas as a waste product. | physics | 2 |
What is the term for rain that has a ph less than 5, due to carbon dioxide dissolving? | geneology | hardhat | nebuli | acid rain | Acid rain is rain that has a pH less than 5 (see Figure below ). The pH of normal rain is 5.6. It’s slightly acidic because carbon dioxide in the air dissolves in rain. This forms carbonic acid, a weak acid. | physics | 0 |
What gas is released into the atmosphere when fossil fuels are burned? | three-fourth full | velocity and energy | glucose | co2 | Carbon dioxide levels in the atmosphere are increasing. Fossil fuel burning is increasing. The rise in fossil fuel burning is increasing the CO 2 in the atmosphere. | physics | 1 |
What are the most energetic of all electromagnetic waves, which can be used to treat cancer? | chromosomal mutation | basal layer | tetrapod | gamma rays | Gamma rays are the most energetic of all electromagnetic waves. They can pass through most materials, including bones and teeth. Nonetheless, even these waves are useful. For example, they can be used to treat cancer. A medical device sends gamma rays the site of the cancer, and the rays destroy the cancerous cells. If you want to learn more about gamma rays, watch the video at the URL below. | biology | 0 |
When does a baby double in length and triple in weight? | pre-adolescence | terrible twos | fetal stage | infancy | Scientific notation is a way of writing very large or very small numbers that uses exponents. Numbers are written in the format a × 10 b . | biology | 3 |
Where do the cells in your body get oxygen from? | leukocytes | white blood cells | hepatic liverworts | red blood cells | All the cells of your body need oxygen, which they get from red blood cells. Red blood cells, in turn, get oxygen in the lungs. The lungs are the main organs of the respiratory system. The respiratory system is the body system that exchanges gases with the outside air. It brings air containing oxygen into the body for the cells. It also releases carbon dioxide from the cells into the air. | biology | 1 |
What type of generations do plants alternate between during a life cycle? | rinse, reuse, recycle | innate behaviors | chronic fever | haploid and diploid | All plants have a life cycle that alternates between haploid and diploid generations. Plants vary in terms of which generation is dominant. Most modern plants have a dominant diploid generation. | biology | 0 |
Genetic diversity in a population comes from two main sources - sexual reproduction and what else? | spermatozoa | rain | education | mutation | Variation and Adaptation Natural selection can only take place if there is variation, or differences, among individuals in a population. Importantly, these differences must have some genetic basis; otherwise, selection will not lead to change in the next generation. This is critical because variation among individuals can be caused by non-genetic reasons, such as an individual being taller because of better nutrition rather than different genes. Genetic diversity in a population comes from two main sources: mutation and sexual reproduction. Mutation, a change in DNA, is the ultimate source of new alleles or new genetic variation in any population. An individual that has a mutated gene might have a different trait than other individuals in the population. However, this is not always the case. A mutation can have one of three outcomes on the organisms’ appearance (or phenotype):. | biology | 1 |
What state of matter completes the list: solid, liquid, gas? | maps | dissonance bonds | knee | plasma | A snowflake is made of ice, or water in the solid state. A solid is one of four well-known states of matter. The other three states are liquid, gas, and plasma. Compared with these other states of matter, solids have particles that are much more tightly packed together. The particles are held rigidly in place by all the other particles around them so they can’t slip past one another or move apart. This gives solids a fixed shape and a fixed volume. | physics | 0 |
The heart, blood vessels, and blood make up which system in the body? | essential amino acids | flowers, leaves, bark | sleep | cardiovascular | The cardiovascular system is made up of the heart, the blood vessels, and the blood. | biology | 3 |
What unit of measurement is typically used for rainfall? | ground level | gymnosperms | geologic maps | inches | geography | 0 |
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Which elements fall between metals and nonmetals in the periodic table? | individual molecules | peak | lipid mass | metalloids | Metalloids are elements that fall between metals and nonmetals in the periodic table. Just seven elements are metalloids, so they are the smallest class of elements. In Figure above , they are color-coded orange. Examples of metalloids include boron (B), silicon (Si), and germanium (Ge). | chemistry | 1 |
What is it called when bones get longer and bigger? | reproduction | sessile leaves | replication | growth | biology | 3 |
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What kind of reactions are involved in processes ranging from the contraction of muscles to the digestion of food? | five | metagenomics | moving heat | chemical | The rates at which chemical reactions take place in organisms are very important. Chemical reactions in organisms are involved in processes ranging from the contraction of muscles to the digestion of food. For example, when you wave goodbye, it requires repeated contractions of muscles in your arm over a period of a couple of seconds. A huge number of reactions must take place in that time, so each reaction cannot take longer than a few milliseconds. If the reactions took much longer, you might not finish waving until sometime next year. | biology | 2 |
Mycorrhizae functions as a physical barrier to what? | a stationary front | its core | secondary pollutant | pathogens | Mycorrhizae: The Symbiotic Relationship between Fungi and Roots A nutrient depletion zone can develop when there is rapid soil solution uptake, low nutrient concentration, low diffusion rate, or low soil moisture. These conditions are very common; therefore, most plants rely on fungi to facilitate the uptake of minerals from the soil. Fungi form symbiotic associations called mycorrhizae with plant roots, in which the fungi actually are integrated into the physical structure of the root. The fungi colonize the living root tissue during active plant growth. Through mycorrhization, the plant obtains mainly phosphate and other minerals, such as zinc and copper, from the soil. The fungus obtains nutrients, such as sugars, from the plant root (Figure 31.11). Mycorrhizae help increase the surface area of the plant root system because hyphae, which are narrow, can spread beyond the nutrient depletion zone. Hyphae can grow into small soil pores that allow access to phosphorus that would otherwise be unavailable to the plant. The beneficial effect on the plant is best observed in poor soils. The benefit to fungi is that they can obtain up to 20 percent of the total carbon accessed by plants. Mycorrhizae functions as a physical barrier to pathogens. It also provides an induction of generalized host defense mechanisms, and sometimes involves production of antibiotic compounds by the fungi. | physics | 1 |
What do skeletal muscles enable the body to do? | fetuses | dirscriptor rna | siliceous | move | Skeletal Muscles. Skeletal muscles enable the body to move. | biology | 0 |
What is the sum total of all body reactions? | immunity | archaeans | growth | metabolism | Water is an essential part of most metabolic processes within organisms. Metabolism is the sum total of all body reactions, including those that build up molecules ( anabolic reactions ) and those that break down molecules ( catabolic reactions ). In anabolic reactions, water is generally removed from small molecules in order to make larger molecules. In catabolic reactions, water is used to break bonds in larger molecules in order to make smaller molecules. | biology | 2 |
What type of reproduction involves combining genetic material from two parents to create distinct offspring? | improve sediment quality | skin cancer | bsexual reproduction | sexual reproduction | That is the main difference between sexual and asexual reproduction. Sexual reproduction is combining genetic material from two parents, usually from two gametes. How the two cells combine may take many forms, but does not necessarily involve physical contact. Sexual reproduction produces offspring that are genetically distinct from other offspring and from their parents. Asexual reproduction produces offspring from just one parent. These offspring are genetically identical to that one parent. | biology | 2 |
What kind of molecule is made from one or more long chains of amino acids? | compass | horizontal compounds | amino molecule | protein molecule | A protein molecule is made from one or more long chains of amino acids, each linked to its neighbors by covalent bonds. Multiple chains of a protein are held together by weaker bonds. | chemistry | 1 |
What part of the heart receives the blood is pumped from veins of the systemic circuit? | right ventricle | left atrium | left ventricle | right atrium | Figure 40.10 The mammalian circulatory system is divided into three circuits: the systemic circuit, the pulmonary circuit, and the coronary circuit. Blood is pumped from veins of the systemic circuit into the right atrium of the heart, then into the right ventricle. Blood then enters the pulmonary circuit, and is oxygenated by the lungs. From the pulmonary circuit, blood re-enters the heart through the left atrium. From the left ventricle, blood re-enters the systemic circuit through the aorta and is distributed to the rest of the body. The coronary circuit, which provides blood to the heart, is not shown. | biology | 3 |
What type of properties are characteristics that describe matter? | hydro | cytosine | base | physical | The properties that chemists use to describe matter fall into two general categories. Physical properties are characteristics that describe matter. They include characteristics such as size, shape, color, and mass. Chemical properties are characteristics that describe how matter changes its chemical structure or composition. An example of a chemical property is flammability—a material’s ability to burn—because burning (also known as combustion) changes the chemical composition of a material. | physics | 0 |
What is the leading cause of death in the united states? | branch | suicide | change in the rna sequence of dna | heart disease | Cardiologist Heart disease is the leading cause of death in the United States. This is primarily due to our sedentary lifestyle and our high trans-fat diets. Heart failure is just one of many disabling heart conditions. Heart failure does not mean that the heart has stopped working. Rather, it means that the heart can’t pump with sufficient force to transport oxygenated blood to all the vital organs. Left untreated, heart failure can lead to kidney failure and failure of other organs. The wall of the heart is composed of cardiac muscle tissue. Heart failure occurs when the endoplasmic reticula of cardiac muscle cells do not function properly. As a result, an insufficient number of calcium ions are available to trigger a sufficient contractile force. Cardiologists (cardi- = “heart”; -ologist = “one who studies”) are doctors who specialize in treating heart diseases, including heart failure. Cardiologists can make a diagnosis of heart failure via physical examination, results from an electrocardiogram (ECG, a test that measures the electrical activity of the heart), a chest X-ray to see whether the heart is enlarged, and other tests. If heart failure is diagnosed, the cardiologist will typically prescribe appropriate medications and recommend a reduction in table salt intake and a supervised exercise program. | biology | 3 |
What results when gas particles rebound off the walls of their container? | volume increases | fossil | uniform intermolecular forces | pressure | Pressure is what results when gas particles rebound off the walls of their container. The basic unit of pressure is the newton per square meter (N/m2). This combined unit is redefined as a pascal (Pa). One pascal is not a very large amount of pressure. A more useful unit of pressure is the bar, which is 100,000 Pa (1 bar = 100,000 Pa). Other common units of pressure are the atmosphere (atm), which was originally defined as the average pressure of Earth’s atmosphere at sea level; and mmHg (millimeters of mercury), which is the pressure generated by a column of mercury 1 mm high. The unit millimeters of mercury is also called a torr, named after the Italian scientist Evangelista Torricelli, who invented the barometer in the mid1600s. A more precise definition of atmosphere, in terms of torr, is that there are exactly 760 torr in 1 atm. A bar equals 1.01325 atm. Given all the relationships between these pressure units, the ability to convert from one pressure unit to another is a useful skill. | physics | 2 |
How do most fish reproduce with one another? | same sex | on land | asexually | sexually | Fish reproduce sexually. They lay eggs that can be fertilized either inside or outside of the body. In most fish, the eggs develop outside of the mother's body. In the majority of these species, fertilization also takes place outside the mother's body. The male and female fish release their gametes into the surrounding water, where fertilization occurs. Female fish release very high numbers of eggs to increase the chances of fertilization. | biology | 3 |
What is the ability to cause changes in matter? | pressure | force | generation of electricity | energy | Energy is the ability to cause changes in matter. For example, your body uses chemical energy when you lift your arm or take a step. In both cases, energy is used to move matter—you. Any matter that is moving has energy just because it’s moving. The energy of moving matter is called kinetic energy. Scientists think that the particles of all matter are in constant motion. In other words, the particles of matter have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter . You can learn more about the theory at this URL: http://www. youtube. com/watch?v=Agk7_D4-deY . | physics | 2 |
The group 18 gases that have 8 valence electrons are referred to as what type of gases? | phototaxis | yo-yo | decibel | noble | A common way to keep track of valence electrons is with Lewis electron dot structures . In an electron dot structure, each atom is represented by its chemical symbol, and each valence electron is represented by a single dot. Note that only valence electrons are shown explicitly in these diagrams. For the main group elements, the number of valence electrons for a neutral atom can be determined by looking at which group the element belongs to. In the s block, Group 1 elements have one valence electron, while Group 2 elements have two valence electrons. In the p block, the number of valence electrons is equal to the group number minus ten. Group 13 elements have three valence electrons, Group 14 elements have four, and so on. The noble gases in Group 18 have eight valence electrons, and the full outer s and p sublevels are what give these elements their special stability. Representative dot diagrams are shown in the Figure below :. | physics | 0 |
Competition is a relationship between organisms that depend on the same resources. the resources might be food, water, or what? | dendritic cells | disease | ediacara and transposons | space | Competition is a relationship between organisms that depend on the same resources. The resources might be food, water, or space. Competition can occur between organisms of the same species or between organisms of different species. | biology | 0 |