To determine if the gene for bristle length in Drosophila is sex-linked, a femal

Question

To determine if the gene for bristle length in Drosophila is sex-linked, a female fly from a stock of true-breeding short-bristled flies is mated with a male breeding long-bristled (wild-type) flies. Which of the following results are expect if the gene is sex-linked and long bristles are dominant? [2 pts] All male progeny will have short bristles. All female progeny will have short bristles. All male progeny will have long bristles bristles. All progeny, regardless of sex, will have long bristles.

Explanation / Answer

Ans. All the progeny, regardless of sex, will have long bristles

In Drosophila, sex determination is achieved by a balance of female determinants on the X chromosome and male determinants on the autosomes. Normally, flies have either one or two X chromosomes and two sets of autosomes. If there is but one X chromosome in a diploid cell (1X:2A), the fly is male. If there are two X chromosomes in a diploid cell (2X:2A), the fly is female (Bridges 1921, 1925).

Since all the progeny will have X (sex) chromosome, and long bristles are dominent, expected that all progeny will have long bristles.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.