You want to draw a linkage map for three genes in the fruit fly ( A , b , C ) th

Question

You want to draw a linkage map for three genes in the fruit fly (A, b, C) that you suspect are linked. You have done a three-point testcross and found the following: in the 1500 progeny of the cross, 612 are a · b · c, 603 are A · b · C, 93 are a · b · C, 85 are A · b · c, 53 are a · b · C, 47 are A · b · c, 5 are A · b · C, and 2 are a · b · c. From these data, you can deduce that the genes are linked and that _____ is the order of the genes on the chromosome. ACB ABC BAC CBA CAB You want to draw a linkage map for three genes in the fruit fly (A, b, C) that you suspect are linked. You have done a three-point testcross and found the following: in the 1500 progeny of the cross, 612 are a · b · c, 603 are A · b · C, 93 are a · b · C, 85 are A · b · c, 53 are a · b · C, 47 are A · b · c, 5 are A · b · C, and 2 are a · b · c. From these data, you can deduce that the genes are linked and that _____ is the order of the genes on the chromosome.

Explanation / Answer

The double cross over progenies has least numbers in the progenies. Therefore, AbC and aBc are the double cross over progenies.

The highest numbers progenies are parental type; therefore, abc and AbC are parental type. Now other progenies are single cross over product. Here we see in single cross over that allele ‘b’ is not changing to B, this is only possible when it presents in between of the two alleles. Therefore, the gene order is ABC. We will choose the second option. The 4th one is not to choose if there is one order present. Both orders are right.

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

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