I know there is no 4 phenotypes oooo Sprint 540 PM Question

.oooo Sprint 5:40 PM Question 1 2 pts Females with the genotype hv. aremated to mains with the genotype ab/ there is not between these genesineither sex howmany phenotypes are produced in the F1?0assumeaandbare Question 2 2 pts Referring to the previous question the most frequent F1 phenotype ab Question 3 2 pts Suppose the genes a and b were 20cMapart, and recombination occurmed in females but males abe females were crossed to b males the following phenotypes would be observed ranied from mosttolcast (abl-l lino other phenotypes Question 2 pts

Solution

Females=ab/++ or aa+bb+

Males= ab/+b or aa+bb

aa+bb+ are mated with aa+bb

Gametes from aa+bb+= a+b+, a+b, ab+ and ab

Gametes from aa+bb= a+b and ab

Now do the dihybrid cross

a+b+

a+b

ab+

ab

a+b

a+a+b+b

a+a+bb

a+ab+b

a+a bb

a+b

a+a+b+b

a+a+bb

a+ab+b

a+a bb

ab

a+a b+b

a+a bb

aab+b

aabb

ab

a+a b+b

a+a bb

aab+b

aabb

Phenotype class 1: a+a+b+b, a+a+b+b, a+ab+b

Phenotype class 2: a+a+bb, a+a bb

Phenotype class 2: aabb

We got 3 phenotypic classes.

Question 1:

Answer is 3

Question 2:

Most frequent F1 phenotype is ++ or a+b+

Question3:

Answer is (++) (a+) (+b) (ab)

As the two genes, a and b are 10 m.u apart. They produce 10 recombinants and 90 parental combinations, if it is kept in mind, the ++ will be most frequent and ab will be least frequent.

	a+b+	a+b	ab+	ab
a+b	a+a+b+b	a+a+bb	a+ab+b	a+a bb
a+b	a+a+b+b	a+a+bb	a+ab+b	a+a bb
ab	a+a b+b	a+a bb	aab+b	aabb
ab	a+a b+b	a+a bb	aab+b	aabb