AP Biology Practice Test 42

Test Information

Question 12 questions

Time 15 minutes

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1. For which molecule is energy storage a major function?

Questions 2-3 refer to the following information.

The following graph shows changes in species abundance with time from early to late successional stages of a temperate forest community typical of the eastern United States.

2. Which successional stage would contain the greatest abundance of plants with an r-selected life history?

3. Which successional stage would contain the greatest abundance of hardwood trees?

4. Which of the following is most likely to promote the formation of two species in which only one species existed before?

Questions 5-8 refer to the following information.

In fruit flies, a gene for eye color is X-linked. The dominant wild type allele produces red eyes (R), and the recessive mutant allele produces white eyes (r). A female who is heterozygous for red eyes is crossed with a white-eyed male.

5. What are the expected phenotypic results for this cross with respect to eye color and sex?

6. An experimental cross produced the results shown in the following table.

PhenotypeFemalesMales
red-eyed3020
white-eyed2030

What is the chi-square (χ2) statistic for the observed results?

7. How many degrees of freedom (df) are there for this experiment?

8. What can you conclude from the results of the χ2 statistical analysis?

Questions 9-12 refer to the following information.

A researcher is investigating the success of a procedure that transfers plasmids to bacteria. She uses a recombinant plasmid that contains a gene that gives resistance to the antibiotic tetracycline.

To determine the success of the procedure, she prepares two batches of bacteria: one with untreated bacteria, the other with bacteria that have been treated with the recombinant gene. She also prepares two kinds of agar plates: one with tetracycline and one without. She transfers the two kinds of bacteria to the two kinds of agar plates.

The results of the experiment are shown here, with the number of bacterial colonies indicated.

Number of Colonies on Agar Plate
no tetracycline with tetracycline
normal bacteriaresult I: numerousresult III: 0
treated bacteriaresult II: numerousresult IV: 15

9. What does a comparison of results I and II indicate?

10. What does a comparison of results III and IV indicate?

11. Why is the number of colonies on the tetracycline agar for the treated bacteria limited to 15 instead of showing numerous colonies?

12. What could explain the appearance of one bacterial colony (instead of zero colonies) for result III?