In guinea pigs, white coat (w) is recessive to black coat (W), and wavy hair (v) is recessive to straight hair (V). A breeder crosses a guinea pig that is homozygous for white coat and wavy hair with a guinea pig that is homozygous for black straight hair. The F1 are then crossed with guinea pigs having white coats and wavy hair in a series of testcrosses. The following progeny are produced from these testcrosses:black, straight 30black, wavy 11white, straight 12white, wavy 31total 84a. Are the genes that determine coat color and hair type assorting independently?b. If the genes are not assorting independently, what is the recombination frequency between them?

(a) The genes are not separately sorted

(b) the recombination frequency 0.512 or 51.2%

Explanation:

The cross is a dihybrid cross which invoke the inhetance of two patterns of characters.

A homozygous individual for a given character has identical copies for that character.

Hence Black & Straight = WWVV

White & Wavy = wwvv.

Given that w is recessive to W, and v is recessive to V, a cross between homozygous black and straight (WWVV) and homozygous white and wavy(wwvv) will give all F1 offspring to be black and straight ( WVwv).

Now, a testcross between  F1 and white cote and wavy hair (wwvv) will give the phenotype (the physical characters).

(A test cross is used to emphasize the genotype of an individual when it is crossed with a known genotype.)

#black & straight = 4, Expected = (4/16) ×84 = 21,  Observed = 30

#white & straight (recombinant) = 4,  Expected = (4/16) ×84 = 21,  Observed = 12

#black & wavy (recombinant) = 4, Expected = (4/16) ×84 = 21,  Observed = 31

#white & wavy = 4, Expected = (4/16) ×84 = 21,  Observed = 11

Now the white & wavy and the black and wavy are the recombinants.

From the expected ratio and the

observed statistics, since there is a difference between the observed and the expected, we conclude are not separately sorted

(b) the recombinant frequency = 12+31/84

= 0.512 or 51.2%