In chickens, the creeper trait is a semi-lethal dominant allele that results in

Question

In chickens, the creeper trait is a semi-lethal dominant allele that results in shortened legs, so that the chickens must creep along. Creepers are heterozygous for the allele. Yet, in the homozygous state the allele is lethal and embryos do not develop to hatching. Times are hard, and you must breed your creeper chickens for offspring to sell. If you mate two creeper chickens, and they produce 45 eggs that hatch, on average how many of those chicks would you expect to be normal, not creepers? Unhatched eggs are not included in the 45.

Explanation / Answer

Creepers are heterozygous and thus cross between Cc X Cc results in 45 eggs.

Cc X Cc

The normal chicken have genotype CC. The cross results in 1 normal, two creeper with heterozygous genotype (Cc) and 1 unhatched egg (lethal) with genotype cc.

Therefore, 1/4 or 25% of offspring would be normal and 50% would be creeper.

In 45 eggs produced, the number of normal chicks would be = 45/4 = 11.25 or 11

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.