If a heterozygous brown-eyed (Bb) individual is crossed with a homozygous blue-eyed (bb) individual, what percentage of the offspring will have brown eyes?(1 point) Responses 0% 0% 25% 25% 50% 50% 100%

1 answer

To determine the percentage of offspring that will have brown eyes from a cross between a heterozygous brown-eyed individual (Bb) and a homozygous blue-eyed individual (bb), we can use a simple Punnett square.

  • The alleles from the brown-eyed parent (Bb) can be either B or b.
  • The alleles from the blue-eyed parent (bb) can only be b.

The possible combinations from the Punnett square will be:

  • Bb (brown eyes)
  • bb (blue eyes)
  • Bb (brown eyes)
  • bb (blue eyes)

Here are the offspring combinations:

  1. Bb (brown eyes)
  2. bb (blue eyes)

This gives us:

  • 2 Bb (brown-eyed)
  • 2 bb (blue-eyed)

Thus, the genotypic ratio is 2 Bb : 2 bb, or simplified, 1:1.

In percentage terms, half of the offspring (1 out of 2) will have brown eyes:

  • Brown-eyed offspring: 50%
  • Blue-eyed offspring: 50%

Therefore, the answer is 50% of the offspring will have brown eyes.