Can all offspring in a cross between two chickens show the Creeper phenotype?

The assertion that one of the parents must be homozygous for the Creeper allele to ensure that all offspring exhibit the Creeper phenotype is correct due to the nature of the genetic inheritance involved. The Creeper phenotype in chickens is typically associated with a dominant allele. If one parent is homozygous for this dominant Creeper allele, it carries two copies of the allele, which provides a higher likelihood that the offspring will inherit this allele from that parent.

When a homozygous parent is crossed with a heterozygous parent, all offspring can inherit at least one Creeper allele. Since the homozygous parent contributes a Creeper allele consistently, even if the heterozygous parent contributes either a Creeper or a non-Creeper allele, there’s a significant chance that all offspring can exhibit the Creeper phenotype or at least have a much higher likelihood of doing so than a cross between two heterozygous parents.

In contrast, if both parents were heterozygous for the Creeper allele, some offspring could inherit two non-Creeper alleles, resulting in a non-Creeper phenotype. Therefore, the notion that one parent must be homozygous for the Creeper allele is crucial in understanding how the phenotype