664144488 | A localized group of organisms that belong to the same species is called a: | Population | | 1 |
664144489 | The main source of energy for producers in an ecosystem is: | light energy | | 2 |
664144490 | Which branch of biology is concerned with the naming and classifying of organisms? | taxonomy | | 3 |
664144491 | Prokaryotes are classified as belongig to two different domains. What are the domains? | Bacteria and Archaea | | 4 |
664144492 | Which of these provides evidence of the common ancestry of all life? | the near universality of the genetic code. | | 5 |
664144493 | Charles Darwin proposed a mechanism for descent with modification that stated that organisms of a particular species are adapted to their environment when they possess: | inheritable traits that enhance their survival and reproductive success in the local environment. | | 6 |
664144494 | What is the major distinguishing characteristic of fungi? | Absorbing dissolved nutrients. | | 7 |
664144495 | Why is the theme of evolution considered to be the core theme of biology by biologists? | It provides a framework within which all biological investigation makes sense. | | 8 |
664144496 | Which of the following is the best description of a control for an experiment? | The control group is matched with the experimental group except for one experimental variable. | | 9 |
664144497 | All of the organisms on your campus make up: | a community. | | 10 |
664144498 | Which of the following statements best distinguishes hypotheses from theories in science? | Hypotheses usually are relatively narrow in scope; theories have broad explanatory power. | | 11 |
664144499 | Through time, the linage that led to modern whales shows a change from four-limbed land animals to aquatic animals with two limbs that function as flippers. This change is best explained by: | Natural Selection. | | 12 |
664144500 | When the body's blood glucose level rises, the pancreas secretes insulin and, as a result, the blood glucose level declines. When the bgl is low, the pancreas secretes glucagon and, as a result, the bgl rises. Such regulation of the bgl is the result of: | negative feedback. | | 13 |
664144501 | Organisms interact with their environments, exhanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into: | the potential energy of chemical bonds. | | 14 |
664144502 | To understand the chemical basis of inheritance, we must understand the molecular structure of DNA. This is an example of the application of which concept to the study of biology? | reductionism. | | 15 |
666930254 | About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up
approximately 96% of living matter? | carbon, hydrogen, nitrogen, oxygen | | 16 |
666930255 | Why is each element unique and different from other elements in chemical properties? | Each element has a unique number of protons in its nucleus. | | 17 |
666930256 | Knowing just the atomic mass of an element allows inferences about which of the following? | the number of protons plus neutrons in the element | | 18 |
666930257 | The precise weight of a mole of some pure elements like silicon (Si) can vary slightly from the standard atomic mass, or even from sample to sample, why? | The element may have multiple stable isotopes, and the isotopic composition may vary from sample to sample | | 19 |
666930258 | The atomic number of nitrogen is 7. Nitrogen -15 is heavier than nitrogen -14 because the atomic nucleus of nitrogen -15 contains how many neutrons? | 8 | | 20 |
666930259 | What is the maximum number of electrons in a 2p orbital of an atom? | 2 | | 21 |
666930260 | A covalent chemical bond is one in which | outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both | | 22 |
666930261 | What results from an unequal sharing of electrons between atoms? | Polar covalent bonds | | 23 |
666930262 | Which of the following molecules contains the most polar covalent bond? | H2O | | 24 |
666930263 | What is the difference between covalent bonds and ionic bonds? | Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between atoms. | | 25 |
666930264 | In ammonium chloride salt (NH4Cl) the anion is a single chloride ion, Cl. What is the cation of NH4Cl? | NH4, with a charge of +1 | | 26 |
666930265 | Which of the following explains most specifically the attraction of water molecules to one another? | hydrogen bond | | 27 |
666930266 | Which of the following correctly describes any reaction that has reached chemical equilibrium? | The rate of the forward reaction is equal to the rate of the reverse reaction. | | 28 |
666930267 | Compared with 31P, the radioactive isotope 32P has | one more neutron. | | 29 |
666930268 | Which statement is true of all atoms that are anions? | The atom has more electrons than protons. | | 30 |
666945882 | In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by: | Polar covalent bonds. | | 31 |
666945883 | The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called? | Hydrogen bond. | | 32 |
666945884 | Water molecules are able to form hydrogen bonds with: | compounds that have polar covalent bonds. | | 33 |
666945885 | A dietary Calorie equals 1 kilocalorie. Which of the following statements correctly defines 1 kilocalorie? | 1,000 calories, or the amount of heat required to raise the temperature of 1 kg of water by 1°C | | 34 |
666945886 | Why does ice float in liquid water? | Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water. | | 35 |
666945887 | You have a freshly-prepared 0.1M solution of glucose in water. Each liter of this solution contains how many
glucose molecules? | 6.23x10^23 | | 36 |
666945888 | A strong acid like HCl | ionizes completely in an aqueous solution. | | 37 |
666945889 | Which of the following ionizes completely in solution and is considered to be a strong base (alkali)? | NaOH | | 38 |
666945890 | A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance? | It is a strong acid that ionizes completely in water. | | 39 |
666945891 | What is the hydrogen ion [H+] concentration of a solution of pH 8? | 10^-8M | | 40 |
666945892 | If the pH of a solution is decreased from 9 to 8, it means that the | concentration of H+ has increased tenfold (10X) and the concentration of OH- has decreased to one-tenth (1/10) what they were at pH 9. | | 41 |
666945893 | If the pH of a solution is increased from pH 5 to pH 7, it means that the | concentration of OH- is 100 times greater than what it was at pH 5. | | 42 |
666945894 | Which of the following statements is true about buffer solutions? | They maintain a relatively constant pH when either acids or bases are added to them. | | 43 |
666945895 | Buffers are substances that help resist shifts in pH by | both donating H+ to a solution when bases are added, and accepting H+ when acids are added. | | 44 |
666945896 | Research indicates that acid precipitation can damage living organisms by | washing away certain mineral ions that help buffer soil solution and are essential nutrients for plant
growth. | | 45 |
666945897 | If a solution has a pH of 7, this means that | the concentration of H+ ions in the water equals the concentration of OH- ions in the water. | | 46 |
666945898 | How would acidification of seawater affect marine organisms? | Acidification would decrease dissolved carbonate concentrations and hinder growth of corals and shell building animals. | | 47 |
666945899 | If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, this means that | the concentration of H+ ions is tenfold higher in the cytoplasm than in the mitochondrial matrix | | 48 |
666945900 | We can be sure that a mole of table sugar and a mole of vitamin C are equal in their | Number of Molecules | | 49 |
666945901 | One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3).
Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion
(H+). Thus,
H2CO3 HCO3-+ H+
If the pH of the blood drops, one would expect | the HCO3-to act as a base and remove excess H+with the formation ofH2CO3 | | 50 |
666956085 | The element present in all organic molecules is: | carbon | | 51 |
666956086 | The complexity and variety of organic molecules is due to: | The chemical versatility of carbon atoms. | | 52 |
666956087 | Stanley Miller's 1953 experiments proved that | organic molecules can be synthesized abiotically under conditions that may have existed on early Earth. | | 53 |
666956088 | How many electron pairs does carbon share in order to complete its valence shell? | 4 | | 54 |
666956089 | A carbon atom is most likely to form what kind of bond(s) with other atoms? | covalent. | | 55 |
666956090 | Why are hydrocarbons insoluble in water? | The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. | | 56 |
666956091 | Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that | are mirror images of one another. | | 57 |
666956092 | A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning this compound? | It should dissolve in water. | | 58 |
666956093 | Which two functional groups are always found in amino acids? | carboxyl and amino | | 59 |
666956094 | (Two molecules have same #s but are shaped differently)
33) The two molecules shown in the figure above are best described as | cis-trans isomers | | 60 |
666956095 | Which functional group shown above is characteristic of alcohols? | -OH | | 61 |
666956096 | Which functional group(s) shown above is (are) present in all amino acids? | COOH NH2 | | 62 |
666956097 | Which of the groups above is a carboxyl functional group? | COOH | | 63 |
666956098 | Which of the groups above is an acidic functional group that can dissociate and release H+ into a solution? | COOH | | 64 |
666956099 | Which of the groups above is a basic functional group that can accept H+ and become positively charged? | NH2 | | 65 |
670333185 | Humans and mice differ because: | their cells have some differences in the sequence of nucleotides in their nucleic acids. | | 66 |
670333186 | Molecules with which functional groups may form polymers via dehydration reactions? | either hydroxyl or carboxyl groups | | 67 |
670333187 | Which of these classes of biological molecules consist of both small molecules and macromolecular polymers? | carbohydrates | | 68 |
670333188 | Which of the following is not a polymer? | glucose | | 69 |
670333189 | What is the chemical reaction mechanism by which cells make polymers from monomers? | dehydration reactions. | | 70 |
670333190 | Which of the following polymers contain nitrogen? | chitin | | 71 |
670333191 | The molecular formula for glucose is C6H1206. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions? | C18H32O16 | | 72 |
670333192 | All of the following are polysaccharides except | lactose | | 73 |
670333193 | Which of the following is true of both starch and cellulose? | they both are polymers of glucose | | 74 |
670333194 | Which of the following is true of cellulose? | It is a major structural component of plant cell walls | | 75 |
670333195 | Humans can digest starch but not cellulose because | Humans have enzymes that can hydrolyze the "a" glycosidic linkages of starch but not the "B" glycosidic linkages of cellulose | | 76 |
670333196 | Which of the following statements conceming saturated fats is not true? | They have multiple double bonds in the carbon chains of their fatty acids | | 77 |
670333197 | The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. What is the result of adding hydrogens to vegetable oil? | They hydrogenated vegetable oil stays solid at room temperature | | 78 |
670333198 | Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. Which of the following is an exception to this statement? | a steriod | | 79 |
670333199 | All of the following contain amino acids except: | cholesterol | | 80 |
670333200 | The bonding of two amino acid molecules to form a larger molecule requires: | The release of a water molecule | | 81 |
670333201 | There are 20 different amino acids. What makes one amino acid different from another? | different side chains (R groups) attached to an "a" carbon | | 82 |
670333202 | Upon chemical analysis a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein? | 99 | | 83 |
670333203 | Which bonds are created during the formation of the primary structure of a protein? | peptide bonds | | 84 |
670333204 | What maintains the secondary structure of a protein? | hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond | | 85 |
670333205 | The tertiary structure of a protein is the | unique three-dimensional shape of the fully folded polypeptide. | | 86 |
670333206 | If cells are grown in a medium containing radioactive 35S, which of these molecules will be labeled? | proteins | | 87 |
670333207 | Which of the following statements about the 5' end of a polynucleotide strand of DNA is correct? | The 5' end has a phosphate group attached to the number 5 carbon of ribose | | 88 |
670333208 | If 14C-labeled uridine triphosphate is added to the growth medium of cells, what macromolecules will be
labeled? | RNA | | 89 |
670333209 | Which of the following descriptions best fits the class of molecules known as nucleotides? | nitrogenous base, a phosphate group, and a pentose sugar | | 90 |
670333210 | Which of the following are nitrogenous bases of the purine type? | guanine and adenine | | 91 |
670333211 | If a DNA sample were composed of 10% thymine, what would be the percentage of guanine? | 40% | | 92 |
670333212 | The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA | contains one less oxygen atom | | 93 |
670333213 | If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence: | 5'TGCAAT3' | | 94 |
670333214 | What is the structural feature that allows DNA to replicate? | complementary pairing of the nitrogenous bases | | 95 |