In mice, black coat colour (allele B) is dominant to brown coat colour (allele b). The offspring of a cross between a black mouse (BB) and a brown mouse (bb) were allowed to interbreed. What percentage of the progeny would have black coats ?

Question

In mice, black coat colour (allele B) is dominant to brown coat colour (allele b). The offspring of a cross between a black mouse (BB) and a brown mouse (bb) were allowed to interbreed. What percentage of the progeny would have black coats ? (A) 25 % (B) 50 % (C) 75 % (D) 100 %

Tardigrade Admin · Accepted Answer

The cross between black mouse (BB) and a brown mouse (bb) and the inbreeding of their hybrid progeny is shown below. <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/biology/0360e7b592f9c4561ac4f8eacb696809-.jpeg" /> Hence, phenotypic ratio is 3 black: 1 brown i.e. 75 % of the progeny would have black coat.

Q. In mice, black coat colour (allele $B$ ) is dominant to brown coat colour (allele b). The offspring of a cross between a black mouse $(BB)$ and a brown mouse $(bb)$ were allowed to interbreed. What percentage of the progeny would have black coats ?

$25%$

$50%$

$75%$

$100%$

The cross between black mouse $(BB)$ and a brown mouse $(bb)$ and the inbreeding of their hybrid progeny is shown below.

Hence, phenotypic ratio is $3$ black : $1$ brown i.e. $75%$ of the progeny would have black coat.

Q. In mice, black coat colour (allele B) is dominant to brown coat colour (allele b). The offspring of a cross between a black mouse (BB) and a brown mouse (bb) were allowed to interbreed. What percentage of the progeny would have black coats ?

25%

50%

75%

100%