In a species of bird, there is a dominant allele for long beaks (B) and a recessive allele for short beaks (b).

Question

If a homozygous dominant, long-beaked bird is crossed with a homozygous recessive, short-beaked bird, what percent of the offspring would have short beaks?
0%
25%
50%
100%

Answer 1

In this scenario, we have:

• Homozygous dominant long-beaked bird: BB
• Homozygous recessive short-beaked bird: bb

When you cross these two birds (BB × bb), all offspring will inherit one allele from each parent.

The possible combinations for the offspring will be:

• From the BB parent, all offspring will inherit a B allele.
• From the bb parent, all offspring will inherit a b allele.

Therefore, all offspring will have the genotype Bb.

Since Bb represents a long-beaked phenotype (due to the dominance of the B allele), none of the offspring will have short beaks (bb).

Thus, the percent of the offspring that would have short beaks is 0%.