Passage III

The characteristics and genetics of D. pseudoobscura (a species of fruit fly) have been studied extensively. Table 1 shows the average egg production of different races and strains of female D. pseudoobscura at various temperatures throughout their lifetimes.

Table 2 shows the results of a study on testis length in male D. pseudoobscura with different combinations of Race A and Race B chromosomes. Male D. pseudoobscura have one X chromosome, one Y chromosome, two Number 2 chromosomes, two Number 3 chromosomes, and two Number 4 chromosomes.

15. A male D. pseudoobscura had the following chromosomes: one X chromosome from Race B, two Number 2 chromosomes from Race B, two Number 3 chromosomes from Race B, one Number 4 chromosome from race A, and one Number 4 chromosome from Race B. Accordingly, its average testis length was most likely closest to which of the following values?

Answer and Explanation

Your Answer is

Correct Answer is C

Explanation

Look at table 2, according to the description of the title, the genotype of the male D. pseudoobscura should be X (B), BB, BB, AB, corresponding to Group 11, so the corresponding height is 480 μm