Question

By applying the rules of probability to the following cross, Rr x Rr, determine the probability of the offspring being homozygous recessive?
1/2




1/4




3/4

Answer 1

1/4 because the products are, RR Rr Rr or rr

Answer 2

Answer:

Option B, $\frac{1}{4}$

Explanation:

The cross is carried out between two parents having genotype "Rr"

Here allele "R" is dominant over allele "r"

The punnet square representing the cross between two parents having genotype "Rr" is as follows -

R r

R RR Rr

r Rr rr

Out of all offspring,  the recessive homozygous offspring is "rr"

Thus, the probability of offspring being homozygous recessive is

$\frac{1}{4}$

Hence, option B is correct.