A geneticist is mapping the chromosomes of the newly captured gremlin. The strip

Question

A geneticist is mapping the chromosomes of the newly captured gremlin. The stripe is heterozygous for three linked genes with alleles Ee, Hh, and Bb, that determine if gremlin:s are evil (E), have hair (H), and biting teeth (B). In order to determine if the three genes are linked, a standard testcross was done, and the 1000 offspring had the following genotypes 48 36 ee 400 ee Hh Bb ee Hh bb hh Bb Ee Hh Bb Ee hh Bb 26 Ee hh bb 46 38 Ee Hh bb Choose the alleles on the homologous chromosomes of the heterozygous individuals with the correct gene order hbE HBe hBE hEb HeB Ehb HEB heb EhB eHB

Explanation / Answer

According to the data given innthe question, Ee hh bb and ee Hh Bb are parental types (most frequent) and ee hh bb and Ee Hh Bb are double recombinants types ( least frequent ).

The next point is that a double crossover event moves the middle allele from one sister chromatid to the other. This places the non-parental allele of the middle gene on to a chromosome with the parental alleles of two flanking genes. So, by comparing parental alleles and double recombinants types E gene should be in the middle. Also by seeing the two parental types there is Ee is present with hh bb alleles in one parent and ee is present with Hh Bb in 2nd parent. Thus,

----h-----E----- b------ ----H----e------B------- is the correct answer.

  

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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