You\'ve become the world\'s expert on Athenos beetles, and you\'re especially in

Question

You've become the world's expert on Athenos beetles, and you're especially interested in the genes that control the patterning on the scutellum. So, you collected several mutant strains that have the same remarkable heart-shaped pattern. For pairwise combinations in complementation tests, the results are shown in this table, where + represents complementation and 0 represents no complementation.

Mice that are homozygous for null mutations in the gene that encodes enzyme A (genotype aa) don't make either antigen 1 or antigen 2. Mice that are homozygous for null mutations in the gene that encodes enzyme B (genotype bb) don't make antigen 1. Mice that are homozygous for null mutations in the gene that encodes enzyme C (genotype cc) don't make antigen 2. All three genes are unlinked.

Two different true-breeding strains of mice have been isolated that don’t make either antigen 1 or antigen 2. When an individual from one strain is crossed with an individual from the other strain, all of the F1 mice produce both antigens.

QUESTIONS:

A.

What are the complete genotypes of the two parental strains?

Select two.

?aabbcc

Part B

Two of the F1 mice are crossed to one another. What proportion of the F2 progeny will produce both antigen 1 and antigen 2?

Enter your answer as a fraction.

Thank you in advance, please explain!

?AABBCC ?AAbbCC ?AABBcc ?AAbbcc ?aaBBCC ?aaBBcc ?aabbCC

?aabbcc

Part B

Two of the F1 mice are crossed to one another. What proportion of the F2 progeny will produce both antigen 1 and antigen 2?

Enter your answer as a fraction.

Thank you in advance, please explain!

enzyme B antigen 1 enzyme A intermediate enzyme antigen 2

Explanation / Answer

AABBCC ......synthesize both antigen 1 and 2

AAbbCC........ synthesize only antigen 2 because gene B is missing so they can not synthesize antigen 1

AABBcc.... synthesize only antigen 1 because gene A is missing so they can not synthesize antigen 2

AAbbcc niether Antigen 1 nor Antigen 2 is synthesized.

aa BBCC, aa BBcc and aa bbCC genotype mice in all these case both antigen will be missing.

Part B

when cross between AABBcc X AAbbCC

then the progeny will be AABbCc (so F1 progny mice express both antigen)

when   AABbCc X AABbCc

AABBCC AABBCc   AABBCc    AABBCc   AABbCC AABbCc AABbCc AABbcc AABbCC   AABbCc   AABbCc AABbcc AAbbCC AAbbCc AAbbCc AAbbcc (these kind of progeny will produced) .

so some of the progeny express both antigen 1 and 2 both (e.g. AAB..C..) while some of express only Antigen 1 only (e.g. AAB..cc) while some of the progeny only 2 (e.g. AAbbC...).

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

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