AP BIO THINGY

39. Carbon dioxide most likely enters a cell through which of the following processes?

simple diffusion

51. Which of the following best explains why a cell's plasma membrane is composed of 2 layers of phospholipids rather than just a single layer?

two opposite layers... hydrophilic portion faces inside and outside of the cell.

28. If NaF is added to cells undergoing cellular respiration, which of the following will most likely accumulate in the cells?

two phosphoglycerate

34. A researcher has identified a compound that reverses the effect of drug X. Based on figure 3, which of the following best explains how the compound acts in the pathway to reverse the effects of drug X?

*34 Refer to docs for picture cuz I aint paying 3.99*

65.Which of the following describes a mutation that would lead to an increase in the frequency of nondisjunction? (nondisjunction - failure of sister chromatids to separate properly)

A mutation affecting checkpoint 3 proteins that prevents attachment of spindle fibers

76. Which of the following best explains why bile salts cause the sulfur powder to sink?

Bile salts decrease surface tension.

13. Which of the following best explains how DCMU affects the reaction?

DCMU acts as an inhibitor to the movement of electrons within the light reaction of photosynthesis.

66.Maturation promoting factor, MPF, is a cyclin-CDK complex that catalyzes the phosphorylation of other proteins to start mitosis. The activity level of MPF is dependent on the relative concentrations of the cyclin and CDK components of MPF (Figure 1). Based on Figure 1, which of the following describes the role of cyclin in the regulation of the cell cycle?

During M phase, the cyclin level peaks, resulting in an increased binding frequency with CDK.

5. Which of the following describes the most likely location of cholesterol in an animal cell

Embedded in the plasma membrane

43. Hormones are chemical signals that are released by cells in one part of the body that travels through the bloodstream to signal cells in another part of the body. Based on the info provided, which of the following best justifies the claim that osteocalcin is a hormone?

The osteoblasts secrete osteoid something to change their activity

82.Which of the following best explains how the phospholipid bilayer of a transport vesicle contributes to cellular functions?

The phospholipid bilayer allows the vesicle to fuse with the Golgi apparatus and the plasma membrane, allowing the exocytosis of proteins.

52. Which of the following best explains why larger grapes have a different rate of water absorption per gram of mass than smaller grapes do?

The rate is slower because smaller grapes have larger surface-to-volume than larger grapes do.

61. Pyruvate dehydrogenase is an enzyme. Which of the following observations provides the best evidence that acetyl-CoA negatively regulates pyruvate dehydrogenase activity?

The rate of the pyruvate dehydrogenase-catalyzed reaction is slower in the presence of a higher concentration of acetyl-CoA.

23. Which of the following best explains how water is able to move upward from the roots of a plant through its xylem in the stem and out to the leaves?

Water molecules and xylem are both polar.

83. If 30% of the nucleotides in a single-stranded RNA molecule are adenine, then what percent are expected to be thymine?

ZEROOOOOOOOOOOO%

2. Which of the following research questions would guide an investigation of the link between the structure of the signaling molecules and evolution of quorum sensing?

common ancestor with similar signaling molecule

70. High levels of certain plant nutrients in runoff can lead to rapid growth of an algae (an algae bloom) in aquatic ecosystems. Those algal blooms are generally followed by algal death and decomposition, which consumes large amounts of dissolved oxygen in the water and results in oxygen levels insufficient to support aerobic respiration. Which of the following was the dependent variable in the researcher's study?

concentration of chlorophyll a

20. Which of the following graphs best represents the data in table 1?

line graph

60. Which of the following is represented by the gradual increase in thickness of the cirous(?) from the top to the bottom of figure 1?

number of proteins/ enzymes increases.

18. Which of the following was the dependent variable in the researchers experiment?

pH

21. According to the data, which of the following best explains the results of the experiment?

pH of the treatment culture was lower that pH of control because the chemical increased the bacterial metabolic rate.

46. A researcher observes that mice form the mutant strain experience low blood sugar, which of the following best describes the feedback mechanism in figure 1 causing the low blood sugar in the mutant strain?

positive feedback of insulin production

57. Assuming a negligible pressure, which of the following best predicts the net movement of the sample diffusive solutes and water in the second experiment?

small molecules diffuse into the grape, followed by water.

81. Mutation in gene coding for single-polypeptide enzymes results in substitution of amino acid serine, which was the polar R group, but amino acid phenylalanine, nonpolar R groups mutated, has lower activity. Which explains how amino acid substitution has resulted in decreased catalytic activity by mutated enzymes.

the change in sequence changes the secondary and tertiary protein structure, changing the active site of the enzyme.

56. A student hypothesized that the solute concentration of grape juice is higher than the solute concentration of the actual grape juice that has added sugar. Based on the figure, which of the following best evaluates the student's hypothesis?

the hypothesis is not supported because mass of the grape increased

45. Which of the following best describe the effect of insulin binding to the receptor on osteoblasts cells

Leads to additional insulin

12. Which of the following chains is best supported by the experimental results?

Light is required for the electron transport chain to transfer electrons.

31. Based on figure 2, which of the following best supports the claim that drug X inhibits oxygen consumption?

Line 3 has less oxygen with the drug than without

3. Which of the following best describes the hydrolysis of carbohydrates?

The addition of a water molecule breaks a bond between sugar monomers.

24. Which of the following best explains how molecules such as O2 and CO2 can move across the membrane of a cell?

Small nonpolar molecules can diffuse through membranes.

4. UV radiation can damage DNA by breaking weak bonds. Which of the following best explains how this occurs?

UV radiation disrupts the double helix structure by breaking the hydrogen bonds between the nitrogenous base pairs

75. A scientist designed an experiment to test an artificial membrane that mimics the phospholipid bilayer of a cell. The scientist built a tube that was divided by an artificial membrane and filled with distilled water. The scientist put a known amount of a protein into the water on one side of the membrane. After some time, the scientist measured the concentration of the protein on either side of the membrane but found that there had been no change. Which of the following experimental changes would allow the scientist to observe transport of a solute across the artificial membrane?

Use a small, nonpolar solute instead of a protein.

80. Which of the following types of bonds is most likely responsible for the unusual base pairing shown in Fig 3 that results in the formation of a triplex DNA structure.

hydrogen bonding between base pairs.

48. A researcher investigating effects of chemical that makes thylakoid membrane permeable to hydrogen ions, which fo the following is the most likely direct effect of adding the chemical to plant cells?

less ATP can be made.

68.Based on the data in figure 1, which of the following most likely represents the change in energy that occurs when ATP hydrolysis is coup;ed with the phosphorylation of a substrate?

line 1 - ATP hydrolysis, line 4- phosphorylation

42. Which of the following best describes the production of DMSP by coral and coral symbiont?

negative feedback that reverses environmental change

44. Which of the following was a positive control in the experiment?

normal strain

50. Based on the data, which type of cell would be best suited for the lining of the alveoli of the lungs where diffusion of CO2 and O2 must occur rapidly?

simple squamous- 9

14. DCPIP is a chemical dye. When DCPIP is chemically reduced, it changes color from blue to clear. Which of the following best justifies the use of tube 2 as a control treatment?

It was a positive control for measuring the effect of DCMU on the reaction.

32. Which of the following best describes the data in figure 1?

10upm? increase/ X reduces melanoma cell survival

29. Based on figure 1, the net number of ATP molecules produced during glycolysis from the metabolism of a single glucose molecule is closest to which of the following?

2

22. Based on the data in Table 1, which of the following is the earliest time point at which there is a statistical difference in average pH between control and treatment groups?

35 minutes

41.Certain reef-building corals contain photosynthetic, symbiotic algae that have the ability to make DMSP. Which of the following best describes the scientist's findings concerning the density of symbiosis presented in Figure 2?

37 and 25 different in day 5 and day 10

53. Based on table 1, which of the following percent is closest to the solute concentration of the grape?

5.5%

25. Which of the following best explains the mechanisms by which alanine inhibits pyruvate kinase activity?

Alanine binds to allosteric site (A)

71. Which of the following best explains how higher concentrations of nitrogen and phosphorus contribute to eutrophication?

Algae require nitrogen and phosphorus to build macromolecules, so higher concentrations of these nutrients can result in algal blooms.

63. Which of the following is evidence that eukaryotes and prokaryotes share a common ancestor?

All eukaryotes and prokaryotes contain ribosomes.

49. Amylase is an enzyme that converts carbohydrate polymers into monomers. Glycogen synthase is one of the enzymes involved in converting carbohydrate monomers into polymers. Which of the following best explains the reactions of these enzymes?

Amylase aids in the addition of a water molecule to break covalent bonds whereas glycogen synthase aids in the removal of a water molecule to form covalent bonds.

69. Scientists investigated the effect of oxygen levels on the rate of carbon fixation in two types of plants. Which of the following statements about the rate of carbon fixation in the two types of plants is supported by the data shown in the figures?

At 21% O2, plant type 2 has a lower rate of CO2 fixation than plant type 1 does in both types of soil

27. Tarui disease is an inherited disorder that is caused by mutations in PFKM, the gene that encodes a subunit of phosphofructokinase, an enzyme in the glycolysis pathway. Individuals with Tarui disease produce little or no functional phosphofructokinase in skeletal muscle cells. Based on Figure 1, which of the following best explains why a low carbohydrate diet is recommended for those with Tarui disease?

Carbohydrate metabolism requires all the reactions of glycolysis, and amino acids and fatty acids do not

78. Ethylene gas is an organic molecule that serves many cell signaling roles in flower plants. Which of the following best explains how a positive feedback mechanism involving ethylene works?

Cells of signaling fruit produce ethylene, which activates the ripening response in other fruit cells.

64. Newborn babies hibernating animals contain ATP BATs that increase permeability if the inner mitochondrial membrane disrupts proton gradient. Which of the following best predicts the effect of disrupting the proton gradient in BAT?

Electron transport and oxidative phosphorylation will be decoupled, generating more heat but less ATP

10. Which of the following explains the connection between energy, growth. And the maintenance of an ordered system in the experiment. (grass with 3 sections)

Energy input from light maintained order system.

9. Two types of cells, alpha and beta cells, produce signaling molecules that affect blood sugar levels in opposite ways. Based on figure 1, which of the following best explains how exercise causes blood glucose levels to rise?

Epinephrine activates alpha cells, causing the release of glucagon, and inhibits beta cells, blocking the release of insulin.

47. Which of the following claims is most consistent with the data shown in figure 2?

Esp expression is necessary to prevent the overproduction of insulin

8. Figure 1 shows a model of the endocrine signaling pathway that regulates ovulation which of the following observations would provide evidence of a positive feedback mechanism in this system?

Estrogen from the ovaries stimulates the hypothalamus and anterior pituitary to secrete more GnRH, LH, and FSH.

77. Which of the following best describes the process by which gas from the atmosphere is obtained by plants and used to build lipids?

Gas is directly obtained by plants as part of the carbon cycle.

30. Which of the following describes why a glucose transporter is needed to move glucose into the cell?

Glucose is large and polar

26. An increase in the concentration of protons in the cytoskeleton will most likely have which of the following effects on glycolysis?

Glycosidic enzyme will denature as a result of the increased + H concentration

54. Based on table 1, which of the following best explains the different in water potential between certain solutions and the grapes?

Grape soda and NaCl have a lower water potential because these two solutions caused the grape to lose water.

74.A researcher measured the temperature at which two different samples of double-stranded DNA denature (separate into single strands). Sample 1 denatures at a significantly lower temperature than sample 2 did. Which of the following best supports the researcher's claim?

Guanine and Cytosine have more hydrogen between them.

79. Humans produce sweat as a cooling mechanism to maintain a stable internal temperature. Which of the following best explains how the properties of water contribute to this physiological process?

High heat of vaporization allows the body to remove excess heat through water from liquid to gas.

1. Which of the following research questions was best addressed by the experiment?

How did the chemical messengers affect the transitions of the cell cycle

67. Which of the following best describes the role of water in photosynthesis?

It is the source electrons for electron transport chain

7. Which of the following best illustrates the flow of info required for the synthesis of proteins encoded in the genome of a retrovirus?

RNA-DNA-RNA-Protein

35. Which of the following is the strongest evidence supporting the endosymbiosis hypothesis?

Mitochondria has own DNA and divide independently

16. On average more ATP can be produced from an NADH molecule than can be produced from a molecule of FADH2

NADH goes through 4 protein complexes, whereas FADH2 goes through 3 protein complexes.

17. A typical bag of fertilizer contains high levels of nitrogen, phosphorus, potassium but trace amounts of magnesium and calcium. Which of the following best matches the fertilizer component with the molecule in which it will be incorporated by organisms in the area?

Nitrogen to nucleic acids

40. What evolutionary advantage does compartmentalization of core metabolic processes offer eukaryotes...

Nucleus (?)

33. Based on the info presented, which, of the following best explains why the researchers measured oxygen consumption as an indicator of the effectiveness of drug X

Oxygen accepts electrons in oxidative phosphorylation , a process necessary for melanoma cell survival

38. Trypsin and pepsin are enzymes that function in different areas of the digestive tract. One functions in the stomach, where the pH is between 1.5 and 3.5, while the other functions in the small intestines, where the pH is between 6 and 8. Based on Figure 1, which of the following best describes where each enzyme functions?

Pepsin works in the stomach because the optimal pH for pepsin is acidic.

59. A student placed a semipermeable membrane inside a U-shaped channel with two chambers, as shown. The membrane permits the movement of water but not salt. The student wants to vary the rate of osmosis that occurs across the membrane. Which of the following experimental designs will result in the fastest net rate of water movement into chamber A?

Placing salty water in A and distilled water in B.

36. The amino acid in figure 1 is found in a region of a polypeptide that folds away from water. Which part of the amino acid most likely contributes to the hydrophobia behavior of this region of the polypeptide?

R group (methyl)

72. Which of the following describes the relationship between the amount of chlorophyll a in water sample and the concentration of nitrogen in that sample?

The concentration of chlorophyll a and nitrogen is directly correlated.

6. Which of the following best explains the most likely method by which this anti tumor drug works?

The duplication of DNA was disrupted

62. Which of the following best explains how the extensive folding of inner mitochondrial benefits a eukaryotic cell?

The folded membrane increases the surface area for energy production.

73. The primary function of the kidney is to exchange across membranes between blood and urine. 1 type of kidney cell has basic rectangular shape except for a single surface, which is lined with tiny fingerlike projections that even go into surrounding extracellular space. Which of the following best explains the advantages of these projections provide the cell?

The projections increase the surface area-to-volume ratio of the cell which allows for more efficient nutrient exchange with the environment.

55. Mercurial sulfhydryl is an inhibitor of aquaporins. Which of the following is the most likely effect of adding more(?) sulfhydryl to the distilled water solution?

The rate of water diffusion will be slower.

37. A mutation in the upland cotton plant causes the development of chloroplasts with a single outer membrane and no internal membranes. Which of the following would most likely be observed in chloroplasts of cotton plants with this mutation?

They would be unable to generate the ATP and NADPH needed to make sugars, because these processes occur on membranes within the chloroplast.

15.Scientists were interested in testing the effects of a rotenone, a broad spectrum pesticide, or a cell structure.Based on the data in the table, which of the following best explains the effects of rotenone on cellular respiration?

Treated cells are not able to break down NADH because certain enzymes of the electron transport chain are inhibited.

11. In which of the following tubes did the greatest reduction of DCPIP occur over 60 min?

Tube 2

19. Which of the following best describes the process by which the bacteria are breaking down the glucose to produce lactic acid?

bacteria break down sugars in absence of oxygen

58. Figure 1 shows the amount of product produced in an enzyme catalyze reaction over 5 minutes. Which of the following best explains how the rate of the reaction changes over time.

the rate decreases because the ratio of product to substrate increases.