questions stringlengths 37 1.22k | reasoning stringlengths 0 3.56k ⌀ | answers stringlengths 4 138 |
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What happens when the blood cannot reach the heart because a blood vessel is blocked?
Here are the choices:
A. heart attack
B. fast heart beat
C. pass out
D. heart burn | A heart attack happens when the blood cannot reach the heart because a blood vessel is blocked. If cardiac muscle is starved of oxygen for more than roughly five minutes, it will die. Cardiac muscle cells cannot be replaced, so once they die, they are dead forever. Coronary heart disease is the leading cause of death o... | A: heart attack. |
What kind of solid is characterized by an unorganized and unpredictable structure?
Here are the choices:
A. amorphous
B. magnetic
C. aqueous
D. porous | When water freezes in a non-crystalline, amorphous form as frost, the water molecules are fixed in place, but not in a regular, repeating pattern. Frost and other amorphous solids are characterized by their unorganized and unpredictable structure. Because ice comes in both amorphous and crystalline forms, there are dif... | A: amorphous. |
An object with more mass has greater thermal energy than an object with less mass because it has more what?
Here are the choices:
A. molecules
B. gravity
C. atoms
D. ions | 5. Thermal energy is the energy of moving atoms of matter. All matter has thermal energy because atoms of all matter are constantly moving. An object with more mass has greater thermal energy than an object with less mass because it has more atoms. | C: atoms. |
Ether molecules have an oxygen atom and can engage in hydrogen bonding with which other molecules?
Here are the choices:
A. carbon dioxides
B. proteins
C. lipids
D. water | Ether molecules have an oxygen atom and can engage in hydrogen bonding with water molecules. An ether molecule has about the same solubility in water as the alcohol that is isomeric with it. | D: water. |
What basic structures of the nervous system innervate the muscles of the respiratory system and are responsible for controlling and regulating pulmonary ventilation?
Here are the choices:
A. neurons
B. enzymes
C. ions
D. toxins | Neurons that innervate the muscles of the respiratory system are responsible for controlling and regulating pulmonary ventilation. The major brain centers involved in pulmonary ventilation are the medulla oblongata and the pontine respiratory group (Figure 22.20). | A: neurons. |
Pollutants in surface water can filter into the ground and enter a what?
Here are the choices:
A. hydro plant
B. turbine
C. combustion aquifer
D. groundwater aquifer | Pollutants in surface water can filter into the ground and enter a groundwater aquifer. Irrigation water can bring pesticides and other chemicals. Water can seep through landfills. Tanks of gasoline stored underground can leak. | D: groundwater aquifer. |
What is the most common cause of dwarfism?
Here are the choices:
A. hypothyroidism
B. achondroplasia
C. deformity
D. retinopathy | Whereas cystic fibrosis, Tay-Sachs, and phenylketonuria are all autosomal recessive disorders, achondroplasia is an autosomal dominant disorder. Achondroplasia is the most common cause of dwarfism in humans. Achondroplasia is a result of an autosomal dominant mutation in the fibroblast growth factor receptor gene 3 (FG... | B: achondroplasia. |
What describes how much matter is in a certain amount of space?
Here are the choices:
A. density
B. viscosity
C. volume
D. mass | Density describes how much matter is in a certain amount of space. Substances that have more matter packed into a given space have higher densities. The water in a drinking glass has the same density as the water in a bathtub or swimming pool. All substances have characteristic densities, which does not depend on how m... | A: density. |
Axons pass what on to other cells?
Here are the choices:
A. myelin impulses
B. calcium impulses
C. synthesis impulses
D. nerve impulses | The cell body contains the nucleus and other organelles. Dendrites and axons connect to the cell body, similar to rays coming off of the sun. Dendrites receive nerve impulses from other cells. Axons pass the nerve impulses on to other cells. A single neuron may have thousands of dendrites, so it can communicate with th... | D: nerve impulses. |
Sister chromatids separate and move to opposite poles of the cell in the third phase of what process?
Here are the choices:
A. meiosis
B. cytokinesis
C. epistasis
D. mitosis | third phase of mitosis during which sister chromatids separate and move to opposite poles of the cell. | D: mitosis. |
What is the distance that sound waves travel in a given amount of time called?
Here are the choices:
A. force of sound
B. velocity of sound
C. speed of sound
D. momentum of sound | The speed of sound is the distance that sound waves travel in a given amount of time. The speed of sound in dry air at 20 °C is 343 meters per second. | C: speed of sound. |
What would you call a relationship where the bacteria benefit and and the other organism is harmed?
Here are the choices:
A. fungi
B. pathology
C. symbiotic
D. parasitism | Other bacteria are parasitic and can cause illness. In parasitism , the bacteria benefit, and the other organism is harmed. Harmful bacteria will be discussed in another concept. | D: parasitism. |
What is the supply of water to land or crops to help growth called?
Here are the choices:
A. irrigation
B. drainage
C. absorbtion
D. precipitation | Some of the problems associated with intensive irrigation include all but. | A: irrigation. |
What form of matter has neither a definite shape nor a definite volume?
Here are the choices:
A. liquid
B. plasma
C. solid
D. gas | A gas is a form of matter that has neither a definite shape nor a definite volume. A gas takes up the shape and volume of its container. This is because the particles of a gas are very far apart from one another compared to the particles that make up solids and liquids. Gases are easily compressed because of the large ... | D: gas. |
Which stage has already been completed by the time sea urchin eggs are released from the female?
Here are the choices:
A. mitoses
B. fetus
C. secondary
D. meiosis | D: meiosis. | |
Unlike pure substances, mixtures have a what?
Here are the choices:
A. variable composition
B. unique composition
C. efficient composition
D. complex composition | When two or more pure substances are combined together, a mixture is formed. Unlike pure substances, mixtures have a variable composition. Variable composition indicates that the relative proportions of the mixtures components may vary, and they can be separated by physical methods. There are two main types of mixtures... | A: variable composition. |
What process does not cause a rock to melt completely, instead causing the minerals to change by heat or pressure?
Here are the choices:
A. metamorphism
B. oxidation
C. sedimentation
D. igneous extrusion | Metamorphism does not cause a rock to melt completely. It only causes the minerals to change by heat or pressure. | A: metamorphism. |
A disaccharide is a pair of monosaccharides. disaccharides are formed via dehydration synthesis, and the bond linking them is referred to as a glycosidic bond (glyco- = “sugar”). three disaccharides (shown in figure 2.19) are important to humans. these are sucrose, commonly referred to as table sugar; lactose, or milk ... | Disaccharides A disaccharide is a pair of monosaccharides. Disaccharides are formed via dehydration synthesis, and the bond linking them is referred to as a glycosidic bond (glyco- = “sugar”). Three disaccharides (shown in Figure 2.19) are important to humans. These are sucrose, commonly referred to as table sugar; lac... | C: malt sugar. |
At what age is skeletal maturity reached by humans?
Here are the choices:
A. 30
B. 40
C. 20
D. 15 | Bones become increasingly ossified and grow larger during fetal development, childhood, and adolescence. When skeletal maturity is reached at about age 20, no additional growth in bone length can occur. | C: 20. |
What is most of earth's surface covered with?
Here are the choices:
A. insects
B. water
C. sand
D. silicon | The outer planets in the solar system are giant balls of swirling gas. Earth and the other inner planets are relatively small, dense, and rocky. Most of Earth’s surface is covered with water. As far as we know, Earth is also the only planet that has liquid water. Earth's atmosphere has oxygen. The water and oxygen are ... | B: water. |
What is the sac-like organ of the body that is important for both mechanical and chemical digestion?
Here are the choices:
A. spleen
B. kidney
C. stomach
D. gall bladder | The stomach is a sac-like organ in which food is further digested both mechanically and chemically. (To see an animation of how the stomach digests food, go to the link below. ) Churning movements of the stomach’s thick, muscular walls complete the mechanical breakdown of food. The churning movements also mix food with... | C: stomach. |
All chemical reactions require what to get started?
Here are the choices:
A. primary energy
B. conductivity energy
C. activation energy
D. spiked energy | Some chemical reactions release energy, whereas other chemical reactions absorb energy. All chemical reactions require activation energy to get started. | C: activation energy. |
Mitosis is nuclear division during which duplicated chromosomes are segregated and distributed into what?
Here are the choices:
A. father nuclei
B. long nuclei
C. woman nuclei
D. daughter nuclei | Figure 6.3 A cell moves through a series of phases in an orderly manner. During interphase, G1 involves cell growth and protein synthesis, the S phase involves DNA replication and the replication of the centrosome, and G2 involves further growth and protein synthesis. The mitotic phase follows interphase. Mitosis is nu... | D: daughter nuclei. |
Movement of water and minerals in the xylem solutes, pressure, gravity, and matric potential are all important for what?
Here are the choices:
A. plant water transport
B. increase water transport
C. Moving Water Transport
D. produce water transport | Movement of Water and Minerals in the Xylem Solutes, pressure, gravity, and matric potential are all important for the transport of water in plants. Water moves from an area of higher total water potential (higher Gibbs free energy) to an area of lower total water potential. Gibbs free energy is the energy associated w... | A: plant water transport. |
The temperature of the box is related to the average speed of what?
Here are the choices:
A. earth
B. air
C. molecules
D. light | The temperature of the box is related to the average speed of the molecules. Use momentum principles to relate temperature to pressure. Explain conceptually, in words rather than with equations. | C: molecules. |
What are organisms that eat just one type of food?
Here are the choices:
A. gluttons
B. specialists
C. devotees
D. hedonists | Specialists are organisms that eat just one type of food. Birds that are specialists include ospreys, which eat only live fish. You can see an osprey in Figure below . The osprey’s feet are very well-adapted for catching fish. Its eyes are also well-adapted for seeing fish under the water. Its beak is well suited for g... | B: specialists. |
Mechanisms for establishing cellular asymmetries include morphogen gradients, localized determinants, and what other type of interactions?
Here are the choices:
A. conductive
B. reductive
C. electromagnetic
D. inductive | D: inductive. | |
Biodiversity hot spots are prime candidates for protection because they are prone to what species fate?
Here are the choices:
A. reduction
B. mutation
C. extinction
D. accumulation | C: extinction. | |
What are single-celled or colonial organisms that do not have membranebound nuclei?
Here are the choices:
A. eukaryotes
B. prokaryotes
C. arthropods
D. viruses | Watch this video (http://openstaxcollege. org/l/rotating_DNA) that animates the three-dimensional structure of the DNA molecule shown in Figure 1.15. Some cells contain aggregates of macromolecules surrounded by membranes; these are called organelles. Organelles are small structures that exist within cells. Examples of... | B: prokaryotes. |
Differences in density between water and air lead to differences in what?
Here are the choices:
A. resistance
B. energy
C. pressure
D. sound | Differences in density between water and air lead to differences in pressure. | C: pressure. |
What organizational tool, arguably the best in all of science, lists all the known chemical elements, arranged by atomic number?
Here are the choices:
A. tide table
B. periodic table
C. spreadsheet
D. logic table | Appendix: Periodic Table of the Elements In this chapter, we present some data on the chemical elements. The periodic table, introduced in Chapter 3 "Atoms, Molecules, and Ions", lists all the known chemical elements, arranged by atomic number (that is, the number of protons in the nucleus). The periodic table is argua... | B: periodic table. |
Solvation involves surrounding ions with what?
Here are the choices:
A. solvent particles
B. proteins
C. molecules
D. passive particles | Solvation involves surrounding ions with solvent particles. | A: solvent particles. |
The appendicular skeleton includes all bones of the upper and lower limbs, plus the bones that attach each limb to the what?
Here are the choices:
A. dynamic skeleton
B. axial skeleton
C. literal skeleton
D. compressed skeleton | The Appendicular Skeleton The appendicular skeleton includes all bones of the upper and lower limbs, plus the bones that attach each limb to the axial skeleton. There are 126 bones in the appendicular skeleton of an adult. The bones of the appendicular skeleton are covered in a separate chapter. | B: axial skeleton. |
Cow manure can have a second life as a source of what gas?
Here are the choices:
A. hydrogen
B. freon
C. ethanol
D. methane | Cow manure can have a second life as a source of methane gas, which can be converted to electricity. Not only that food scraps can also be converted into green energy. | D: methane. |
Eggs reside in the mesohyl, but sperm are carried out of the sponge by what?
Here are the choices:
A. ion channels
B. air current
C. phloem
D. water current | D: water current. | |
Population size influences the chances of a species surviving, with very small populations generally at greatest risk of what fate?
Here are the choices:
A. extinction
B. accumulation
C. mutation
D. adaptation | Population size is the number of individuals in a population. For example, a population of insects might consist of 100 individual insects, or many more. Population size influences the chances of a species surviving or going extinct. Generally, very small populations are at greatest risk of extinction. However, the siz... | A: extinction. |
Sound is the transfer of energy from a vibrating object in waves that travel through what?
Here are the choices:
A. matter
B. time
C. water
D. light | Sound is the transfer of energy from a vibrating object in waves that travel through matter. | A: matter. |
Sterols are a subgroup of what?
Here are the choices:
A. antibiotics
B. nutrients
C. nuclides
D. steroids | Steroids (or sterols) have several functions. Sterols are a subgroup of steroids. The sterol cholesterol is an important part of cell membranes and plays other vital roles in the body. Cholesterol is a precursor to fat-soluble vitamins and steroid hormones. Steroid hormones include the male and female sex hormones. Ste... | D: steroids. |
Cardiac muscle is only found where?
Here are the choices:
A. heart
B. brain
C. lung
D. abdomen | Cardiac muscle also contracts and gets shorter. This muscle is found only in the heart. The sudden burst of contraction forces blood throughout your body. When the cardiac muscle relaxes, the heart fills with blood. This rhythmic contraction must continue for your whole life, luckily the heart muscle never gets tired. ... | A: heart. |
What process provides over 99 percent of the energy for life on earth?
Here are the choices:
A. glycolysis
B. fracking
C. farming
D. photosynthesis | Photosynthesis provides over 99 percent of the energy for life on earth. A much smaller group of autotrophs - mostly bacteria in dark or low-oxygen environments - produce food using the chemical energy stored in inorganic molecules such as hydrogen sulfide, ammonia, or methane. While photosynthesis transforms light ene... | D: photosynthesis. |
Unlike energy, what doesn’t need to be constantly added to ecosystems because it is recycled through ecosystems?
Here are the choices:
A. water
B. nutrients
C. matter
D. vapor | Unlike energy, matter doesn’t need to be constantly added to ecosystems. Instead, matter is recycled through ecosystems. Water and elements such as carbon and nitrogen that living things need are used over and over again. | C: matter. |
A colloid is a homogeneous mixture with medium-sized what?
Here are the choices:
A. solutions
B. molecules
C. particles
D. atoms | A colloid is a homogeneous mixture with medium-sized particles. Examples include homogenized milk and gelatin. The particles of a colloid are large enough to reflect light, so you can see them. But they are too small to settle or filter out of the mixture. | C: particles. |
What causes rivers to always flow downhill?
Here are the choices:
A. diffusion
B. slope
C. pressure
D. gravity | Currents are like rivers flowing through the ocean. Rivers always flow downhill because of gravity. What do you think causes ocean currents to flow?. | D: gravity. |
What elements do water and hydrogen peroxide consist of?
Here are the choices:
A. hydrogen and oxygen
B. calcium and oxygen
C. hydrogen and helium
D. carbon and oxygen | Look at the Figure below of water (H 2 O) and hydrogen peroxide (H 2 O 2 ), and read about these two compounds. Both compounds consist of hydrogen and oxygen, but they have different ratios of the two elements. As a result, water and hydrogen peroxide are different compounds with different properties. If you’ve ever us... | A: hydrogen and oxygen. |
Name the virus that causes cold sores.
Here are the choices:
A. herpes virus
B. Epstein-Barr
C. AIDS
D. eboli | Metju12. Cold sores are caused by a herpes virus . Public Domain. | A: herpes virus. |
Cardiac veins parallel the small cardiac arteries and generally drain into what sinus?
Here are the choices:
A. Veins
B. coronary
C. lungs
D. heart | CHAPTER REVIEW 19.1 Heart Anatomy The heart resides within the pericardial sac and is located in the mediastinal space within the thoracic cavity. The pericardial sac consists of two fused layers: an outer fibrous capsule and an inner parietal pericardium lined with a serous membrane. Between the pericardial sac and th... | B: coronary. |
What is a dip slip fault where the dip of the fault plane is vertical?
Here are the choices:
A. strike - theory
B. reverse slip
C. strike-slip
D. incline slip | A strike-slip fault is a dip-slip fault where the dip of the fault plane is vertical. Strike-slip faults result from shear stresses. If you stand with one foot on each side of a strike-slip fault, one side will be moving toward you while the other side moves away from you. If your right foot moves toward you, the fault... | C: strike-slip. |
The major entrance and exit for the respiratory system is which facial orifice?
Here are the choices:
A. mouth
B. nose
C. ear
D. pore | The Nose and its Adjacent Structures The major entrance and exit for the respiratory system is through the nose. When discussing the nose, it is helpful to divide it into two major sections: the external nose, and the nasal cavity or internal nose. The external nose consists of the surface and skeletal structures that ... | B: nose. |
Sexual reproduction is the combination of (usually haploid) reproductive cells from two individuals to form a third (usually diploid) unique offspring. sexual reproduction produces offspring with novel combinations of what?
Here are the choices:
A. features
B. genes
C. phenotypes
D. cells | Sexual Reproduction Sexual reproduction is the combination of (usually haploid) reproductive cells from two individuals to form a third (usually diploid) unique offspring. Sexual reproduction produces offspring with novel combinations of genes. This can be an adaptive advantage in unstable or unpredictable environments... | B: genes. |
What kind of reproduction involves just one parent and produces offspring genetically identical to each other and to the parent?
Here are the choices:
A. asexual reproduction
B. organic reproduction
C. microscopic reproduction
D. sexual reproduction | Asexual reproduction is simpler than sexual reproduction. It involves just one parent. The offspring are genetically identical to each other and to the parent. All prokaryotes and some eukaryotes reproduce this way. There are several different methods of asexual reproduction. They include binary fission, fragmentation,... | A: asexual reproduction. |
What do you call the hard case that surrounds the soft parts of some animals?
Here are the choices:
A. membrane
B. exoskeleton
C. muscles
D. shell | B: exoskeleton. | |
Choosing to not smoke and using sunscreen are examples of lifestyle choices that help prevent forms of what disease?
Here are the choices:
A. cancer
B. pnemonia
C. bacterial disease
D. viral disease | Making healthy lifestyle choices can help prevent some types of cancer. For example, you can reduce your risk of lung cancer by not smoking. You can reduce your risk of skin cancer by using sunscreen (see Figure below ). | A: cancer. |
What is said about the speed of rotation in systems that create tornadoes?
Here are the choices:
A. it is fast
B. it is slow
C. it is unchanged
D. it is magnetic | There are several other examples of objects that increase their rate of spin because something reduced their moment of inertia. Tornadoes are one example. Storm systems that create tornadoes are slowly rotating. When the radius of rotation narrows, even in a local region, angular velocity increases, sometimes to the fu... | B: it is slow. |
In gas exchange, oxygen flows into the blood, and what flows out?
Here are the choices:
A. carbon monoxide
B. liquid dioxide
C. naturally dioxide
D. carbon dioxide | Gas exchange is the movement of oxygen into the blood and carbon dioxide out of the blood. | D: carbon dioxide. |
What happens during the process of digestion?
Here are the choices:
A. regurgitation
B. excretion of food
C. cell division
D. breakdown of food | The digestive system consists of organs that break down food, absorb nutrients, and eliminate waste. The breakdown of food occurs in the process of digestion. | D: breakdown of food. |
What do you call the folded layers of rock where geologists look for oil?
Here are the choices:
A. anticlines
B. synclines
C. crests
D. oscillations | Geologists look for oil in folded layers of rock called anticlines. Oil moves through permeable rock and is trapped by the impermeable cap rock. | A: anticlines. |
Cutting forests and clearing land has also increased the amount of what in the atmosphere?
Here are the choices:
A. pesticides
B. oxygen
C. carbon dioxide
D. smog | Because of human activities, there is more carbon dioxide in the atmosphere today than in the past hundreds of thousands of years. Burning fossil fuels and has released great quantities of carbon dioxide into the atmosphere. Cutting forests and clearing land has also increased carbon dioxide into the atmosphere because... | C: carbon dioxide. |
Microevolution occurs in a population when what frequencies change over time?
Here are the choices:
A. antenna
B. allele
C. molecule
D. eukaryote | Microevolution occurs in a population when its allele frequencies change over time. There are four major forces of evolution that cause allele frequencies to change: mutation, gene flow, genetic drift, and natural selection. | B: allele. |
What is the alkaline hydrolysis reaction of an ester called?
Here are the choices:
A. instantiation
B. fermentation
C. saponification
D. resorption | Saponification describes the alkaline hydrolysis reaction of an ester. The term saponification originally described the hydrolysis of long-chain esters called fatty acid esters to produce soap molecules, which are the salts of fatty acids. One such soap molecule is sodium stearate, formed from the hydrolysis of ethyl s... | C: saponification. |
What is the time interval required for one complete wave to pass a point called?
Here are the choices:
A. period
B. cycle
C. half-life
D. minute | The time interval required for one complete wave to pass a point is called the period . During the period of the wave, an entire wavelength from one crest to the next crest passes a position. The number of waves that pass a single position in one second is called the frequency . The period of a wave and its frequency a... | A: period. |
Plant-like protists are autotrophs, meaning they make their own what?
Here are the choices:
A. food
B. flowers
C. molds
D. spores | Plant-like protists are autotrophs, meaning they make their own food. | A: food. |
In what form do plants and animals store sugar for later use?
Here are the choices:
A. management polysaccharides
B. processing polysaccharides
C. storage polysaccharides
D. carrying polysaccharides | C: storage polysaccharides. | |
What forces the fetus out of the uterus?
Here are the choices:
A. delayed childbirth
B. deep breathing
C. continuous strong contractions
D. biological clock | C: continuous strong contractions. | |
The large and small intestine are both divided into how many parts?
Here are the choices:
A. 3
B. 6
C. 2
D. 8 | From the small intestine, any remaining food wastes pass into the large intestine. The large intestine is a relatively wide tube that connects the small intestine with the anus. Like the small intestine, the large intestine also consists of three parts: the cecum (or caecum), colon, and rectum. Follow food as it moves ... | A: 3. |
If everything in a system stays the same but the pressure deceases, gas bubbles will change in what way?
Here are the choices:
A. they pop
B. they multiply
C. they get bigger
D. they get smaller | Gas bubbles get bigger when they are under less pressure. | C: they get bigger. |
What do you call the transfer of thermal energy?
Here are the choices:
A. heat
B. humidity
C. formation
D. precipitation | Thermal energy is the total energy of moving particles of matter. The transfer of thermal energy is called heat. Therefore, a heating system is a system for the transfer of thermal energy. Regardless of the type of heating system in a home, the basic function is the same: to produce thermal energy and transfer it to ai... | A: heat. |
The outer layer of what anatomical structure is so tough that it keeps out most pathogens?
Here are the choices:
A. steel
B. bark
C. skin
D. liver | This drawing shows that the skin has many layers. The outer layer is so tough that it keeps out most pathogens. | C: skin. |
The process of a liquid becoming a gas is called boiling, while the process of a solid becoming a gas is called what?
Here are the choices:
A. vaporization
B. Melting
C. sublimation
D. Boiling | Temperature does not change during a phase change. The process of a liquid becoming a gas is called boiling; the process of a solid becoming a gas is called sublimation. | C: sublimation. |
How does the nucleus divide during nuclear fission?
Here are the choices:
A. equally
B. asymmetrically
C. biochemically
D. evenly | Collision of a relatively slow-moving neutron with a fissile nucleus can split it into two smaller nuclei with the same or different masses. Neutrons are also released in the process, along with a great deal of energy. Any isotope that can undergo a nuclear fission reaction when bombarded with neutrons is called a fiss... | B: asymmetrically. |
How do heavy alkanes affect the skin?
Here are the choices:
A. damage the skin
B. form a protective layer
C. color the skin
D. they do not affect the skin | Lighter alkanes wash away protective skin oils; heavier alkanes form a protective layer. | B: form a protective layer. |
If an electric current passes through water, water molecules break down into molecules of what?
Here are the choices:
A. hydrogen and oxygen
B. hydrogen and carbon
C. oxygen and methane
D. carbon and oxygen | The arrow in Figure above shows that the reaction goes from left to right, from hydrogen and oxygen to water. The reaction can also go in the reverse direction. If an electric current passes through water, water molecules break down into molecules of hydrogen and oxygen. This reaction would be represented by a right-to... | A: hydrogen and oxygen. |
What makes luminous dials glow in the dark?
Here are the choices:
A. polymer substances
B. eerie substances
C. phosphorescent substances
D. devil substances | Once excited, an atom or molecule will usually spontaneously de-excite quickly. (The electrons raised to higher levels are attracted to lower ones by the positive charge of the nucleus. ) Spontaneous de-excitation has a very short mean lifetime of −8 typically about 10 s . However, some levels have significantly longer... | C: phosphorescent substances. |
What liquid is referred to as the "universal solvent"?
Here are the choices:
A. bromine
B. water
C. gasoline
D. blood | Not only salt, but many other solutes can dissolve in water. In fact, so many solutes can dissolve in water that water has been called the universal solvent. Even rocks can dissolve in water, which explains the cave that opened this article. A solute that can dissolve in a given solvent, such as water, is said to be so... | B: water. |
What is the active ingredient in cloves?
Here are the choices:
A. eugenol
B. methyl
C. thiamine
D. nicotine | Eugenol, the active ingredient in cloves, has the formula C 10 H 12 O 2 . Eugenol is a molecular substance that does not dissociate into ions when dissolved in a solvent. What is the boiling point of a solution in which 0.144 g of eugenol is dissolved in 10.0 g benzene? The k b value for benzene is 2.53 °C/ m , and the... | A: eugenol. |
What term means the adjusting of systems within a cell in order to restore balance or maintain equilibrium?
Here are the choices:
A. systemic regulation
B. aftertouch regulation
C. homeostatic regulation
D. gaseous regulation | Homeostasis refers to the balance, or equilibrium, within the cell or a body. It is an organism’s ability to keep a constant internal environment. Keeping a stable internal environment requires constant adjustments as conditions change inside and outside the cell. The adjusting of systems within a cell is referred to a... | C: homeostatic regulation. |
What is the name of the formation that regulates sleep and arousal?
Here are the choices:
A. epithelial formation
B. sleep-arousal formation
C. reticular formation
D. gelechioidea formation | C: reticular formation. | |
What do the gonadotropins regulate?
Here are the choices:
A. gametogenesis
B. epigenesis
C. mitosis
D. temperature | A: gametogenesis. | |
Valence electrons also determine how well—if at all—the atoms of an element conduct what?
Here are the choices:
A. water
B. light
C. electricity
D. pollution | Valence electrons also determine how well—if at all—the atoms of an element conduct electricity. The copper wires in the cable in the Figure below are coated with plastic. Copper is an excellent conductor of electricity, so it is used for wires that carry electric current. Plastic contains mainly carbon, which cannot c... | C: electricity. |
What celestial bodies are born in clouds of gas and dust called nebulas?
Here are the choices:
A. comets
B. galaxies
C. stars
D. planets | Stars are born in clouds of gas and dust called nebulas. Our Sun and solar system formed out of a nebula. A nebula is shown in Figure below . In Figure above , the fuzzy area beneath the central three stars contains the Orion nebula. | C: stars. |
What does a hydrolase use to split molecules?
Here are the choices:
A. momentum
B. air
C. water
D. gas | Hydrolase – A hydrolase splits a molecule into two fragments by using water. The catalyzed reaction is referred to as a hydrolysis. | C: water. |
What term is used to describe the transfer of thermal energy by particles moving through a fluid?
Here are the choices:
A. diffusion
B. condensation
C. evaporation
D. convection | Convection is the transfer of thermal energy by particles moving through a fluid. Thermal energy is always transferred from an area with a higher temperature to an area with a lower temperature. | D: convection. |
What is the source of precipitation?
Here are the choices:
A. clouds
B. the sea
C. the atmosphere
D. pollution | The atmosphere is a crucial part of the water cycle. It is an important reservoir for water, and the source of precipitation. | C: the atmosphere. |
How does bacteria reproduce?
Here are the choices:
A. sexual reproduction
B. binary fission
C. pollination
D. budding | Binary fission occurs when a parent cell simply splits into two daughter cells. This method is described in detail in the lesson "Cell Division. " Bacteria reproduce this way. You can see a bacterial cell reproducing by binary fission in Figure below . | B: binary fission. |
What causes holes in bread?
Here are the choices:
A. yeast fermentation
B. moisture
C. heat
D. alcohol fermentation | Laurentbonneau. The holes in bread are created by yeast fermentation . CC-BY 3.0. | A: yeast fermentation. |
Which bone is derived from the fusion of four very small coccygeal vertebrae?
Here are the choices:
A. cranium
B. coccyx
C. clavicle
D. femur | The body can also respond effectively to short-term exposure to cold. One response to cold is shivering, which is random muscle movement that generates heat. Another response is increased breakdown of stored energy to generate heat. When that energy reserve is depleted, however, and the core temperature begins to drop ... | B: coccyx. |
Researchers have long based their hypotheses about animal phylogeny on what?
Here are the choices:
A. morphological data
B. manipulative data
C. longitudinal data
D. distinctive data | A: morphological data. | |
The body does not exist in isolation. there is a constant input of water and electrolytes into the system. while osmoregulation is achieved across membranes within the body, excess electrolytes and wastes are transported to the kidneys and excreted, helping to maintain this?
Here are the choices:
A. physical balance
B.... | The body does not exist in isolation. There is a constant input of water and electrolytes into the system. While osmoregulation is achieved across membranes within the body, excess electrolytes and wastes are transported to the kidneys and excreted, helping to maintain osmotic balance. | C: osmotic balance. |
If a sperm fertilizes an egg of a seed plant, the zygote grows into what?
Here are the choices:
A. homostatic embyro
B. pulsation embryo
C. sporophyte embryo
D. progeny embryo | C: sporophyte embryo. | |
Metabolism produces waste energy in the form of heat, which helps what type of animal conserve and maintain heat at a relatively constant body temperature?
Here are the choices:
A. cold-blooded (ectotherm)
B. lizard
C. warm-blooded (endotherm)
D. amphibian | Animal Bioenergetics All animals must obtain their energy from food they ingest or absorb. These nutrients are converted to adenosine triphosphate (ATP) for short-term storage and use by all cells. Some animals store energy for slightly longer times as glycogen, and others store energy for much longer times in the form... | C: warm-blooded (endotherm). |
Electromagnets can be turned on or off and their strength can be changed by controlling what?
Here are the choices:
A. inducing current
B. powered current
C. electric current
D. steady current | Electromagnets can be turned on or off and their strength can be changed by controlling the electric current. | C: electric current. |
In which part of a bird stomach is food stored, soaked and mechanically ground?
Here are the choices:
A. digestion
B. gizzard
C. pancreas
D. Gall bladder | Avian Birds face special challenges when it comes to obtaining nutrition from food. They do not have teeth and so their digestive system, shown in Figure 34.7, must be able to process un-masticated food. Birds have evolved a variety of beak types that reflect the vast variety in their diet, ranging from seeds and insec... | B: gizzard. |
Physical science can be defined as the study of matter and what?
Here are the choices:
A. time
B. natural forces
C. space
D. energy | Physical science can be defined as the study of matter and energy. Matter refers to all the "stuff" that exists in the universe. It includes everything you can see and many things that you cannot see, including the air around you. Energy is what gives matter the ability to move and change. Energy can take many forms, s... | D: energy. |
What is the term for animals that defend their area?
Here are the choices:
A. predatory
B. contain
C. territorial
D. Grazing | Some species of animals are territorial . This means that they defend their area. The area they defend usually contains their nest and enough food for themselves and their offspring. A species is more likely to be territorial if there is not very much food in their area. Having a larger territory could mean more prey o... | C: territorial. |
What is the main reason for weather change?
Here are the choices:
A. seasons
B. climate change
C. moving air masses
D. moving energy masses | Weather is always changing. One day might be cold and cloudy. The next day might be warm and sunny. Even on the same day, the weather can change a lot. A beautiful morning might be followed by a stormy afternoon. Why does weather change? The main reason is moving air masses. | C: moving air masses. |
Most lipids in your diet should be what type, found mainly in plant sources and also in fish?
Here are the choices:
A. unsaturated
B. fat
C. saturated
D. aromatic | Unsaturated fats are found mainly in plant foods, such as vegetable oil, olive oil, and nuts. Unsaturated lipids are also found in fish, such as salmon. Unsaturated lipids are needed in small amounts for good health. Most lipids in your diet should be unsaturated. | A: unsaturated. |
Crude oil is a mixture of different types of what?
Here are the choices:
A. hydrocarbons
B. contaminants
C. greenhouse gases
D. fats | Oil comes out of the ground as crude oil. Crude oil is a mixture of many different hydrocarbons. Oil is separated into different compounds at an oil refinery ( Figure above ). This is done by heating the oil. Each hydrocarbon compound in crude oil boils at a different temperature. We get gasoline, diesel, and heating o... | A: hydrocarbons. |
What is the representative particle in pure metals?
Here are the choices:
A. quark
B. the atom
C. electron
D. neutron | In the case of pure metals, the representative particle is simply the atom. One mole of zinc refers to a mole of Zn atoms. | B: the atom. |
What takes place in the organelle known as the chloroplast, which distinguishes animal from plant cells?
Here are the choices:
A. photosynthesis
B. digestion
C. perspiration
D. reproduction | Photosynthesis takes place in the organelle of the plant cell known as the chloroplasts. Chloroplasts are one of the main differences between plant and animal cells. Animal cells do not have chloroplasts, so they cannot photosynthesize. Photosynthesis occurs in two stages. During the first stage, the energy from sunlig... | A: photosynthesis. |
Organic and biochemical equations show the initial and final products of the equation, respectively known as the reactants and what else?
Here are the choices:
A. products
B. consumers
C. reactors
D. dividends | Note Organic and biochemical equations are frequently written showing only the organic reactants and products. In this way, we focus attention on the organic starting material and product, rather than on balancing complicated equations. Ethanol is oxidized in the liver to acetaldehyde:. | A: products. |
What is used during every step of oil production, from exploration to distribution?
Here are the choices:
A. water
B. coal
C. robots
D. energy | Consider petroleum as an example. Oil companies explore for petroleum in areas where they think it might be. When they find it, they must determine how much is there. They must also know how hard it will be to get. If there's enough to make it worthwhile, they will decide to go for it. To extract petroleum, companies t... | D: energy. |
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