Practice Test 1, Princeton Review AP Biology Prep, 2021

At a Glance

Total Time

1 hour and 30 minutes

Number of Questions

Percent of Total Score

50%

Writing Instrument

Pencil required

Indicate all of your answers to the multiple-choice questions on the answer sheet. No credit will be given for anything written in this exam booklet, but you may use the booklet for notes or scratch work. After you have decided which of the suggested answers is best, completely fill in the corresponding oval on the answer sheet. Give only one answer to each question. If you change an answer, be sure that the previous mark is erased completely. Here is a sample question and answer.

Use your time effectively, working as quickly as you can without losing accuracy. Do not spend too much time on any one question. Go on to other questions and come back to the ones you have not answered if you have time. It is not expected that everyone will know the answers to all the multiple-choice questions.

Many candidates wonder whether or not to guess the answers to questions about which they are not certain. Multiple-choice scores are based on the number of questions answered correctly. Points are not deducted for incorrect answers, and no points are awarded for unanswered questions. Because points are not deducted for incorrect answers, you are encouraged to answer all multiple-choice questions. On any questions you do not know the answer to, you should eliminate as many choices as you can, and then select the best answer among the remaining choices.

Directions: Each of the questions or incomplete statements below is followed by four suggested answers or completions. Select the one that is best in each case and then fill in the corresponding oval on the answer sheet.

The following table lists the intracellular osmolality concentrations of four osmoconforming organisms that are known to mimic the osmotic conditions of their surroundings.

Organism 1	100 mOsm kg^–1
Organism 2	400 mOsm kg^–1
Organism 3	500 mOsm kg^–1
Organism 4	150 mOsm kg^–1
Organism 5	350 mOsm kg^–1

1. If a large amount of salt was added to the sealed tank where organism 4 was being kept, what would be the effect on the intracellular osmolality of organism 4?

(A) Increase initially and then return to the initial state

(B) Increase and maintain the increased state

(D) Decrease and maintain the decreased state

2. Which of the following would likely have the largest direct effect on data in the table?

(A) A mutation in a cytoskeleton protein

(B) A mutation in a protein in the sodium-potassium pump complex

(D) A mutation in a nuclear pore channel protein

3. Which could decrease the osmolalities of the organisms?

(A) Sodium is added to the sealed tank.

(B) Chloride is injected into the organism.

(D) Water is added to the sealed tank.

4. Which of the following statements best describes the insides of these organisms compared to the environment in the tank when they reach osmoconformity?

(A) Due to the influx of water into the organisms’ cells, the organisms’ insides are hypertonic when compared to the tank.

(B) Compared to the tank, the loss of water out of the organisms’ cells makes the organisms’ insides hypotonic.

(C) The organisms’ insides are isotonic since the intracellular osmolality concentrations match the osmolality concentrations of the tank.

(D) The flow of water into and out of the organisms’ insides causes the cells to be retrotonic.

5. A population of organisms that are not osmoconformers is dropped into the tank with Organism 1. The intracellular osmolality of Organism 1 begins to slightly decrease. Which of the following could explain this?

(A) The new organisms were hypotonic compared to the tank and they lost water via osmosis.

(B) The new organisms expelled waste products that increased the tank’s osmolality.

(D) The new organism ingested large amounts of fluid and the tank fluid level decreased.

The active site of the enzyme Ritzolinine (RZN45) contains three positively charged lysine residues. When ascorbic acid is present, binding of JB-76, the substrate of RZN45, decreases. The reaction rate is affected by the presence of ascorbic acid as shown in the figure below. It is thought that a daily supplement of Vitamin C might aid those suffering from Ritzolierre’s Disease, which is caused by elevated levels of RZN45.

6. Which of the following is likely true?

(A) RZN45 and JB-76 have similarly charged amino acids at their active sites.

(B) Ritzolinine is stabilized in the presence of Vitamin C.

(D) JB-76 and ascorbic acid have an identical number of amino acids.

7. Which is the best explanation for the differing effects on reaction rate caused by ascorbic acid at low and high concentrations of JB-76?

(A) At high concentrations of JB-76, there are fewer free active sites for the ascorbic acid to bind to.

(B) At low concentrations of JB-76, there are fewer free allosteric sites for the RZN45 to bind to.

(D) At low concentrations of JB-76, there are more free active sites for the RZN45 to bind to.

8. A patient with Ritzolierre’s Disease would likely benefit from which of the following:

I. Injections of RZN45

II. Injections of JB-76

III. Injections of ascorbic acid

(A) I only

(B) II only

(D) II and III

9. If Figure 1 were to include additional data for higher concentrations of JB-76, how would the reaction rate change?

(A) The reaction rate would be lower than any reaction rate shown in Figure 1.

(B) The reaction rate would be higher than any reaction rate shown in Figure 1.

(D) The reaction rate would increase gradually for each concentration of JB-76 added.

10. The Galapagos Islands contain about 15 species of finches that vary in terms of beak size and strength. The differences are believed to have occurred as a result of allopatric speciation acting on the finch populations. Which of the following best explains how the finch populations developed different beaks?

(A) As finches migrated between islands, alleles were transferred between populations through the process of gene flow.

(B) Genetic drift occurred due to a hurricane near the islands causing a bottleneck effect.

(C) Through convergent evolution, the finches developed comparable features due to being exposed to comparable selective pressures.

(D) Geographic isolation between the different islands kept the populations from breeding with each other, and each population evolved separately.

11. Figure 1 shows a cell at the onset of meiosis (just prior to initiation of prophase I) and the resulting 4 gametes achieved at the end of meiosis. Select the statement that is likely true.

**Figure 1. Resulting gametes from meiosis**

(A) Meiosis occurred as it should.

(B) There was a nondisjunction event in Meiosis I.

(D) Two Barr bodies were produced instead of four gametes.

A gene responsible for production of hair pigment in dogs is called Fursilla (frsl). A map of the Fursilla locus is shown in Figure 1, below. When expressed, it results in darkly pigmented dog fur. When unexpressed, the hair is devoid of pigmentation and appears pure white. Expression of Fursilla (frsl) depends on the binding/lack of binding of several proteins: Nefur (NEFR), Lesfur (LSFR), and Dirkfur (DRKFR). Figure 2 shows the relative levels of frsl transcript as measured via RT-qPCR when each protein is overexpressed or unexpressed in the cell.

12. Scientists identified a mutant allele of the Fursilla gene caused by a deletion of bases 1231-1295 on chromosome 8. What is the likely effect of this mutation?

(A) No transcription and no translation of Fursilla will occur.

(B) Transcription will not occur, but translation will be unaffected.

(D) Both transcription and translation of Fursilla will be unaffected.

13. Which of the following would likely produce a dog with the darkest fur?

(A) High levels of LSFR and high levels of DRKFR

(B) High levels of LSFR and low levels of DRKFR

(D) Low levels of LSFR and low levels of DRKFR

14. Based on the data, which of the following most likely describes how the binding of proteins affects the production of Fursilla transcript?

(A) Because Fursilla transcript levels change when certain proteins are overexpressed or unexpressed in the cell, Fursilla must interfere with the other proteins.

(B) Because Fursilla transcript levels stay the same whether NEFR is overexpressed or unexpressed, NEFR must bind inhibit the production of Fursilla transcript.

(C) Because Fursilla transcript levels decrease when LSFR is unexpressed in the cell, LSFR must compete for the binding site or RNA polymerase.

(D) Because Fursilla transcript levels increase when DRKFR is unexpressed in the cell, DRKFR must compete for the binding site of RNA polymerase.

15. An additional protein, Baldidog (BLD), was identified and found to interact with the DRKFR protein. When they bind together, it has been shown that they fit together because of:

(A) Complementary nucleotides sequences

(B) Amino acid pockets with complementary conformations

(D) Hydrophobic lipids and hydrophobic molecules

16. How would the overexpression of BLD affect the transcript levels of Fursilla?

(A) Fursilla transcript levels would increase.

(B) Fursilla transcript levels would decrease.

(D) Fursilla transcript would completely disappear.

17. Water molecules experience intermolecular forces when interacting with each other. Which of the following would most likely occur if water became a nonpolar molecule?

(A) Polar solutes would dissolve in water forming aqueous solutions of various concentrations.

(B) The amount of liquid water on the planet would increase, and the amount of water vapor in the air would decrease.

(D) Solid water would be more dense than liquid water, so ice would no longer float.

A chain of three small islands was found to be the home to a small species of mouse. The angle of jaw opening was found to vary significantly. The average size angle of the maximal jaw opening found in mice at 10 locations on the three small islands is shown in Figure 1, below.

18. Which of the following might account for the variations in maximal jaw angle?

(A) Different wind speeds on each island

(B) Different heights of trees on each island

(D) Differences in altitude on each island

19. If the mice from Island A and the mice from Island B were placed together, what would likely happen?

(A) The mice would mate, but it is impossible to predict jaw angle.

(B) The mice would mate, and the jaw angle would be approximately 27°.

(D) The mice would not be capable of mating.

20. Skeletons have been found that indicate that mice with jaw angles less than 30 degrees were once found on Island B. Which explanation best accounts for this.

(A) A small jaw angle hinders the survival of mice on Island B.

(B) A large jaw angle hinders the survival of mice on Island A.

(D) A large jaw angle encourages the survival of mice on Island A.

21. Which of the following statements best supports that the jaw angle on Island B changed via punctuated equilibrium?

(A) Fossil evidence has shown that over time the jaw angle on Island B slowly increased.

(B) Fossil evidence has shown that the jaw angle of the mice on Island B increased very quickly.

(D) Fossil evidence has shown that the jaw angle of the mice on Island B fluctuates over time.

22. A scientist studying osmosis placed six similarly sized pieces of potato in sodium chloride solutions of different concentrations and then measured the percent change in mass.

Table 1. % change in mass of potato samples

Sodium chloride concentration	% change in mass
0.1 M	+17.5
0.3 M	+5.0
0.5 M	-7.5
0.7 M	-16.2
0.9 M	-26.1
1.1 M	-25.1

The percent change in mass is closest to 0% at which of the following approximate concentrations of the solutions?

(A) 0.01 M

(B) 0.25 M

(D) 0.45 M

Proteins often need the equivalent of a shipping label so that they can be sent intracellularly or extracellularly to the correct location. These labels are typically found in three forms: signal sequences, target signals, or localization signals. A signal sequence is a stretch of hydrophobic amino acid residues that is only located within polypeptides destined to fold into EITHER extracellular proteins, intermembrane proteins that will anchor to the cell surface, or proteins that will be members of the secretory pathway that packs and ships things towards the cell surface. A targeting signal is a sequence that identifies the proteins of the secretory pathway. A localization signal is a sequence that labels proteins that are destined to go to specific organelles (that are not part of the secretory pathway). The table below shows seven eukaryotic proteins, and the sequences have been identified in each.

23. Which of following could be a description for HRIET1?

(A) A protein found in the blood that plays a role in the immune system

(B) A protein found in the Golgi apparatus that helps tether vesicles

(D) A protein found in the cytosol serving as a cytoskeletal anchor

24. One of the proteins was found to be a receptor for a large protein that is produced in the brain and travels through the blood until it can dock at the target cells that it stimulates. Which of the proteins is likely this receptor?

(A) TMSDG

(B) NUH8

(D) K8TE

25. Two proteins were identified in the electron transport chain. One was found to be active at the beginning of the chain, and the other was found to be active at the final stages of the chain. Which two proteins were these?

(A) HRIET1 and HAZL2

(B) NUH8 and LNACT

(D) TMSDG and TELEE

26. If a scientist was hoping to isolate and purify HAZL2, which of the following techniques would they use?

(A) Collect only the nuclear fraction

(B) Collect only the cytosolic fraction

(D) Collect only the lipid membrane fraction

In a heavily populated suburb, two cougars were once spotted roaming in a small field. Local wildlife experts, though not surprised, warned the public to be aware of their surroundings and to keep small pets protected. A group of local junior high school students were curious about the population of cougars in the area since no one they asked had ever seen one in the area. With the help of local wildlife enthusiasts and carefully placed motion-activated wildlife cameras, the group of students recorded sightings of animals in a local forest preserve for their entire four years of high school. The results are shown below.

27. Raccoons eat a diet rich in berries. Which statement is the most likely to describe the berry population?

(A) A hard frost eliminated nearly all of the berries in 2007, but 2008 was a milder winter.

(B) A virus was introduced in 2006 that eliminated a fly using the berry bushes as a niche habitat.

(D) The berry population remained steady, with a slight decrease due to lower rainfall in 2008.

28. Although the data is limited, which of the following populations is the most likely to be a primary food source for the cougars?

(A) Skunk

(B) Deer

(D) Chipmunk

29. Which change will cause fewer skunks to be sighted in the future?

(A) An increase in the number of cougars

(B) An increase in the number of raccoons

(D) It is impossible to make this determination

30. It has been shown that the population size of chipmunks is directly tied to the number of acorns dropped. This can be scientifically summarized by which of the following statements?

(A) Acorn number is a density-dependent population factor and affects the carrying capacity of the chipmunk population.

(B) Acorn number is a density-dependent population factor and does not affect the carrying capacity of the chipmunk population.

(C) Acorn number is a density-independent population factor and affects the carrying capacity of the chipmunk population.

(D) Acorn number is a density-independent population factor and does not affect the carrying capacity of the chipmunk population.

31. Which of the following populations does NOT demonstrate exponential growth?

I. Cougar

II. Chipmunk

III. Deer

(A) I only

(B) I and II

(D) I and II and III

A certain gene has been identified on chromosome 2 in a species of butterfly. The mRNA transcript has been found to be 1578 base pairs in length. A portion of the transcript is shown below. The area shown in grey is part of a known ribosome binding site.

32. If bases 0–15 were deleted, what would be the likely consequence?

(A) No transcription would be allowed to occur.

(B) No translation would be allowed to occur.

(D) No consequence would occur as these bases are non-coding.

33. A transcript was identified in the nucleus that is similar to this transcript. How is it likely different from the mRNA transcript?

(A) The nuclear transcript likely contained introns.

(B) The nuclear transcript likely contained exons.

(D) The nuclear transcript likely contained a 3’ GTP-Cap.

34. RNA polymerase transcribes DNA into mRNA by matching base pairs of nucleotides. Which of the following would be the segment of DNA on the coding strand corresponding to bases 0–6 in Figure 1?

(A) 5’ AAUGCA 3’

(B) 5’ TTACGT 3’

(D) 3’ TTUGCT 5’

35. Where on the strand shown in Figure 1 is a transcription factor likely to bind?

(A) Bases 0 to 15

(B) Bases 20 to 25

(D) None of the above

36. In a small ecosystem, it is estimated that producers equal approximately 2987 g/m² of biomass. What would be a good guess of how much biomass is found within secondary consumers?

(A) 5974 g/m²

(B) 2987 g/m²

(D) 29.87 g/m²

The enzymatic catalysis of a reaction essential in the production of dog saliva is mediated by the protein ARKKKK60491. ARKKKK60491 is a homodimer, with each subunit being 337 amino acids. Figure 1, below, indicates a modular structure of the homodimer. Three positions are indicated on the model. Position A is the active site. Position B is a region known to have a large number of nonpolar residues. Position C is known to have a large number of charged residues.

37. A mutation is discovered in the gene for ARKKKK60491 that converts positively charged lysine residue into negatively charged glutamic acid residue. This single change directly impacts the location where the substrate to ARKKKK60491 attaches during catalysis. Which position is likely affected by this change?

(A) Position A

(B) Position B

(D) None of the positions will be affected

38. Which of the following is Position B most likely to assist the protein with?

(A) Stabilization of the substrate into the transition state during catalysis

(B) Transportation of catalyzed cargo from the nucleus to the mitochondria

(D) Attachment to the membrane by embedding into the phospholipid bilayer

39. Which of the following statements best predicts the effect on the protein’s structure if the subunits of the homodimer fail to attach?

(A) The primary structure will change because the order of amino acids will differ.

(B) The secondary structure will differ because hydrogen bonds will occur in different locations and the protein will fold into a different shape.

(C) The tertiary structure will be destroyed because the side chain interactions will not occur and the protein will not fold into a 3-dimensional shape.

(D) The quaternary structure will be destroyed because the different amino acid chains will not join together.

40. According to Figure 1, within the protein ARKKKK60491, which of the following locations contain polypeptide N-termini?

I. Position A

II. Position B

III. Position C

(A) I only

(B) I and II

(D) I and III

There are four major types of macromolecules, and each type has specific functions and characteristics. Proteins are made of amino acids and function as enzymes, receptors, hormones, signals, and receptors. Lipids are made of fatty acids and glycerol and function as membrane components and energy storage. Carbohydrates are made of monosaccharides and function as energy storage. Nucleic acids are made of nucleotides and provide genetic information for organisms.

41. Fats are a type of lipid that are generally soluble in organic solvents and generally insoluble in water. Which of the following questions will best guide the researchers to determine if a substance is a fat?

(A) At what temperature does the substance boil?

(B) What type of mixture does the substance form when mixed with water?

(D) Have chemical reactions been recorded between the substance and other chemicals?

42. Sugars are a type of carbohydrate typically made up of hydrogen, carbon, and oxygen. The hydrogen:oxygen ratio is typically 2:1. Which of the following statements explains how carbohydrates function as a stored form of energy?

(A) Excess glucose is stored as glycogen in muscles and the liver.

(B) Glucose is broken down during photosynthesis to act as an energy source.

(D) Glucagon is a hormone that stores excess energy in the pancreas.

43. All four types of macromolecules are organic compounds. Which of the following statements describes a difference between organic and inorganic compounds?

(A) Only organic compounds contain oxygen.

(B) Only organic compounds contain covalently bonded carbon atoms.

(D) Only organic compounds contain ionizing chemical groups.

44. Which of the following could NOT be represented by Figure 1?

(A) A monomer used to build a protein

(B) A nucleotide

(D) A chemical used to relay genetic information

The Dandranian Nettle is a plant native to the Eemagee nation. The nettle produces tiny flowers that come in two colors: white and pink. The petals of the flowers come in two varieties: ruffled or slotted. After years of studying them, it has been widely acknowledged that both traits follow classic Mendelian inheritance patterns of dominance. The table below shows floral phenotypes in a small garden in an isolated greenhouse, where the dominant phenotypes are the most plentiful and researchers assume the population is in Hardy Weinberg equilibrium.

Phenotype	#
White	4900
Pink	400
Ruffled	700
Slotted	4600

45. A true-breeding white nettle is crossed with a true-breeding pink nettle. What will be the ratio of the offspring?

(A) 100% White

(B) 3 White: 1 Pink

(D) 1 White: 3 Pink

46. The F1 generation shown in Table 1 was crossed with a true-breeding pink nettle. What percentage of offspring would have pink flowers?

(A) 0%

(B) 25%

(D) 100%

47. A cross is performed between one nettle that is known to be heterozygous for both traits and a nettle that is pink and ruffled. Which of the following would lead researchers to believe the traits are linked?

(A) Several white flowers are identified with ruffled petals.

(B) Nearly all white flowers also have slotted petals and nearly all pink flowers have ruffled petals.

(D) Flowers are discovered that have two colors of flowers and two shapes of petals.

48. What frequency of the alleles in the greenhouse garden are recessive?

(A) 0.14

(B) 0.27

(D) 0.56

49. What is the frequency of plants in the greenhouse garden that are heterozygous for the flower color trait?

(A) 0.27

(B) 0.39

(D) 0.74

G-protein coupled receptors (GPCRs) are a common type of protein receptor containing seven transmembrane segments and bearing intracellular and extracellular portions. The structure of a typical GPCR and its associated partners is shown below. GPCRs are coupled to G-proteins consisting of three subunits (α, β and γ) that bind the nucleotides GTP or GDP on the intracellular side of the GPCR. The presence or absence of a ligand on the extracellular side of the GPCR determines whether GDP or GTP will bind to the intracellular G-protein. Extracellular ligand binding initiates GDP being exchanged for GTP and the separation of the G-protein. One subunit will travel to join with a secondary partner and will initiate a cascade of signaling effects within the cell. In the example shown below, the secondary partner is adenylyl cyclase and the signaling is cAMP upregulation.

50. A setup like a GPCR is unnecessary in which of the following situations?

(A) The signaling event is very specific

(B) The ligand is a hormone traveling in the bloodstream

(D) The ligand is a small nonpolar molecule

51. Based on Figure 1, which of the following is the first step in the activation of cAMP-dPK?

(A) The exchange of GTP for GDP

(B) The binding of epinephrine

(D) Phosphorylation of intracellular enzymes

52. Which of the following situations is most similar to extracellular binding to a GPCR?

(A) A police officer pulling over a speeding car on the expressway

(B) A celebrity chef visiting the kitchen of another restaurant

(D) A taxi driver picking up a group of passengers

53. What does a GPCR’s capability of making a ligand-induced conformational change allow?

(A) Binding of the ligand to the phospholipid head groups within the membrane

(B) Communication between the outside of the cell and the inside of the cell

(D) Intracellular binding of the GDP-associated G-protein complex

A small family farm has documented Tonduly carrot growth for a hundred years in a Midwest microclimate. The average lengths and masses of the carrots are shown in the table below. The same ecosystem was home to a species of vegetable weevil that attacks the carrots underground. Other than carrots, the weevils also preyed on radishes found in the ecosystem. This particular species of weevil spends its whole life beneath the soil, and the average depth at which these weevils were found each year is shown in the table below.

Table 1. Average lengths and masses of carrots and depth at which weevils are found (by decade)

54. Which carrot phenotype was selected for over time?

(A) Thinner carrots

(B) Longer carrots

(D) Heavier carrots

55. If a weevil were introduced to the ecosystem that lived at a depth of 17 centimeters, how would the carrot length change in the coming years?

(A) It would likely return to its original long size.

(B) It would likely get longer than it has been in the past.

(D) It would not likely change at all with a weevil at 17 centimeters.

56. The average carrot consumer prefers long carrots. What should be done to promote the growth of longer carrots?

I. Remove the weevil population

II. Cross the longest carrot of each generation

III. Introduce a different carrot predator that lives at 10 centimeters

(A) I only

(B) I and II

(D) I and II and III

57. If true, which of the following would account for the average weevil depth changing to 17 centimeters in 2030?

(A) The average carrot length changed to 15 centimeters.

(B) The radishes completely disappeared from the garden.

(D) A small percentage of the weevil population died from a virus.

58. According to Table 1, which of the following traits is most linked to the carrot’s fitness?

(A) Weight

(B) Length

(D) Flavor

59. A dance by the Lenoxian bird is one of the most highly complex mating rituals. Precision and flamboyancy are key to wooing a mate. The natural predator of the Lenoxian bird also enjoys the spirited dance and often strikes during the courtship ritual. Which of the following statements is likely true?

(A) Sexual selection of the most exciting dancers is the driving selective pressure.

(B) Selective pressure against the exciting dancers is the driving selective force.

(D) There can exist a careful balance between multiple opposing selective pressures.

60. Antibiotic resistance occurs when drugs or chemicals used to treat an illness become less effective. Some varieties of Neisseria gonorrhoeae have become resistant to the antibiotic penicillin. Which of the following best explains how the bacteria became resistant?

(A) The bacteria experienced hybrid vigor through gaining improved traits from their parents.

(B) Through natural selection, bacteria with a random mutation that provided resistance survived and multiplied to create more bacteria.

(D) The bacteria evolved to fill different niches from other species in the environment through adaptive radiation.

IF YOU FINISH BEFORE TIME IS CALLED, YOU MAY CHECK YOUR WORK ON THIS SECTION. DO NOT GO ON TO SECTION II UNTIL YOU ARE TOLD TO DO SO.

Directions: Questions 1 and 2 are long free-response questions that should require about 25 minutes each to answer and are worth 8–10 points each. Questions 3 through 6 are short free-response questions that should require about 10 minutes each to answer and are worth 4 points each.

Read each question carefully and completely. Write your response in the space provided following each question. Only material written in the space provided will be scored. Answers must be written out in paragraph form. Outlines, bulleted lists, or diagrams alone are not acceptable unless specifically requested.

1. The microbiome is a collection of microbes, such as bacteria and viruses, that live in/on the human body. Sites of colonization include the skin, nasal passages, mouth, and gut. Links between the microbiome and many different conditions, such as allergies, obesity, depression, and many others have been suggested. During antibiotic use, the body can often suffer repercussions due to the destruction of the natural microbiome. The bacterial community composition varies greatly between body sites. Even among the skin microbiome, there is a great variety in the amounts and types of bacteria found in different locations.

**Figure 1. Relative composition of bacterial communities found in each of four skin microbiomes**

An experiment was performed to assess the results of skin bacterial transplants to alternative sites of the body. A 2-inch square area of interdigital skin was swabbed with a sterile swab to collect bacteria. An additional swab was opened but not touched to the skin. Each swab was then rubbed on either an alternate skin site or the same type of skin site. After 7 days, the skin of the site of deposition was swabbed and plated on a dish to assess bacterial growth. The types of bacteria present were then cataloged.

**Figure 2. The results of rubbing a swab of interdigital skin on four skin sites**

**Figure 3. The results of rubbing a clean swab on four skin sites**

(a) Bacterial communities containing different species of bacteria are no different than other communities with multiple species. Explain what factors contribute to a carrying capacity.

(b) Identify the two important controls that are used in this experiment. In addition, the experiment includes a 7-day waiting period between when the bacterial transplant takes place. Justify why this is necessary.

(c) Interpret the effect of the transplants between interdigital web space and the buttock, external auditory canal, and plantar heel areas.

(d) If each deposition site is pretreated with known antibiotics, explain how this would likely affect the results.

2. Researchers were interested in the effect of temperature on the respiration rate of crickets. Three chambers were prepared and kept at three different temperatures. A cricket was placed in each chamber. The CO₂ levels in the chamber were recorded at 0 minutes, 5 minutes, and 10 minutes to assess the changing levels of CO₂ over time. This process was repeated 50 times at each temperature. The results are indicated in Table 1.

Table 1. Levels of CO₂ over time.

(a) Describe how CO₂ is a measure of respiration. Explain why temperature might affect the rate of respiration.

(b) On a set of axes, construct an appropriately labeled graph to demonstrate the CO₂ levels with changing temperature. Please include all temperatures, timepoints, and error bars.

(d) Predict what would happen to the CO₂ levels in the crickets with an additional 5°C increase above the highest temperature. Justify your prediction with evidence from the data.

3. A researcher was trying to determine why a strain of influenza spreads more easily than other strains. She suspected that the answer might lie in the Influenza Neuraminidase (NA) protein. NA is an enzyme known to play a role in releasing viral particles during viral spread. It functions by cleaving an attachment between viral particles and the cell membrane. The researcher evaluated the enzyme activity of each of the strains and found them to be quite different. She then compared the NA protein from the rapidly spreading strain of flu (NA_H) with the NA protein from another strain of flu (NA_A). The sequences were similar, but there were some differences in the amino acid sequence.

**Figure 1. Amino acid sequence alignment between NA_H and NA_A**

**Figure 2. Neuraminidase enzyme activity**

**Figure 3. Neuraminidase activity of NA_H and NA_H with mutations**

Point mutations were introduced in the nucleic acid sequence to modify the sequence of NA_H to make it more like NA_A. The enzyme activity was assessed.

(a) Explain how changing a single nucleotide can change the sequence of the protein.

(b) Given what is known about the neuraminidase enzyme, describe what is measured to provide the results in Figure 2 and Figure 3.

(d) Justify your prediction.

4. The school is growing tomatoes using a hydroponics system. Hydroponics is a way of growing plants in a controlled system without traditional soil containing nutrients. Instead, nutrients that would be supplied by soils are added to water tanks at specific concentrations before the solution is pumped onto the plant root systems. This type of system allows for increased control over nutrient levels and allows for reduced water usage compared to outdoor crops because of minimal evaporation.

An out-of-control thermostat in the science wing of the school resulted in a temperature that is known to increase thylakoid permeability to H⁺ ions.

(a) Identify which cellular process thylakoids are associated with.

(b) Explain why ions in the hydroponic tank cannot pass into the roots by simple diffusion.

(c) Predict the immediate effect this would have on the cell’s ability to produce reactants necessary for carbon fixation.

(d) Justify your prediction.

**Figure 1. Phylogenetic tree illustrating the relationship of deer tick virus to other tick-borne encephalitis group viruses**

In Figure 1, the values above branches indicate bootstrapped confidence values. Branch lengths are proportional to percent similarity in viral envelope gene sequence. TBE: tick borne encephalitis; TSE: Turkish sheep encephalitis; GGE: Greek goat encephalitis; LI: louping ill virus; SSE: Spanish sheep encephalitis; KFD: Kyasanur Forest disease virus; TYU: Tyuleniy virus; SRE: Saumarez Reef virus.

(a) Describe what is represented by a node in a phylogenetic tree.

(b) Identify two of the viruses that are LEAST similar to GGE.

(c) In 50 years, new data have identified that TBEwest(Hypr) is no longer in circulation, but it seems to have evolved in two directions: TBEwest1 and TBEwest2. Using the empty tree below, correctly indicate TBEwest(neu), TBEwest(Kuml), TBEwest1m, and TBEwest2.

(d) This phylogenetic tree was created using nucleotide sequences. If protein sequences were used instead, explain why this might increase the similarity between the viruses?

6. In a city in Australia there is a population of moths that live in the grass, rarely taking flight except for short journeys. There are two phenotypes for wing color: green and beige. The largest predator of moths are birds and bats that prey upon the moths as they rest upon blades of grass. Green moths fare better in wet conditions when the grass takes on a lush green color and beige moths fare better in dry conditions when the grass turns a dry brown color.

(a) Identify which color moth was the most plentiful between 1969 and 1995?

(b) Explain why the lines of the graph never exceed 100?

(d) Explain how natural selection led to the rise of the beige moth in the late 1970s?

Practice Test 1

AP® Biology Exam

AP^® Biology Exam