Question

In some cats, black coat color (B) is dominant over brown (b) and a striped fur pattern (S) is dominant over a marbled fur pattern (s). You rescued a black striped cat from an animal shelter but could not determine its exact genotype. To do so, you mated the cat with a brown marbled cat. The mating produced 3 brown marbled, 2 brown striped, 2 black marbled, and 3 black striped. Immediately, you concluded the genotype of your rescued cat was:__________
a) BbSS.
b) BBSs.
c) BBSS.
d) BbSs.

Answer 1

Answer:

d. BbSs

Explanation:

As given;

Black coat color (B) is dominant on brown coat color (b);

Striped fur pattern (S) is dominant on a marbled fur pattern (s);

Cross of black, striped cat with brown marbled cat.

As given, brown and marbled is recessive, so brown marbled cat is bbss.

And according to the given offspring, the other parent must be heterozygous.

So black, striped cat is BbSs

cross is between BbSs and bbss

gametes are: parent-1: BS, Bs, bS, bb; Parent-2; bs

offspring is  BbSs, Bbss, bbSs, bbss.

Answer 2

d) is the correct option

Explanation:

B= black coat color (dominant)

b= brown coat color (recessive)

S= striped fur pattern (dominant)

s= marbled fur pattern (recessive)  

A cross is made between black striped cat(genotype unknown) and brown marbled cat (bbss genotype)

(here in this brown marbled cat is homozygous recessive)    

Resulting offsprings are:

3 brown marbled= both coat and fur color recessive

2 brown striped= coat color recessive fur color dominant

2 black marbled= coat color dominant fur color recessive

3 black striped= both coat color and fur color dominant

Crossing brown marbled cat with the genotypes given in options, the correct genotype of rescued cat comes out to be: BbSs