A population of rabbits follows the typical pattern of inheritance and the law of dominance for fur color. B is the allele for black fur and b is the allele for white fur. In a population of rabbits, 120 bunnies are born. How many bunnies should be black, according to the Punnett square?

Question

Responses
A 6060
B 8585
C 9090
D 100100

Answer 1

To determine the expected number of black bunnies from a population of 120 bunnies based on the typical dominant-recessive inheritance pattern for fur color, we can assume the following:

1. Black fur (B) is dominant over white fur (b).
2. The possible genotypes are:
   • Homozygous dominant (BB) - black
   • Heterozygous (Bb) - black
   • Homozygous recessive (bb) - white

Assuming the two alleles (B and b) are randomly combined, the expected phenotypic ratio for these traits is approximately:

• 3 black : 1 white

This ratio represents:

• 3 parts being black (BB or Bb)
• 1 part being white (bb)

If we multiply the total number of bunnies (120) by the fraction that is expected to be black (3/4), we can find the expected number of black bunnies:

\[ \text{Expected number of black bunnies} = 120 \times \frac{3}{4} = 120 \times 0.75 = 90 \]

Based on this calculation, the expected number of black bunnies is 90.

Therefore, the correct answer is:

C. 90