If drooping ears are dominant in dogs over erect ears, what genotype split can be expected? - briefly
When considering the inheritance of ear shape in dogs, where drooping ears are dominant over erect ears, the genotype split can be determined by the principles of Mendelian genetics. The expected genotype split in the offspring of a heterozygous drooping-eared dog (Dd) and an erect-eared dog (dd) would be 1:1 for drooping ears (Dd) to erect ears (dd).
If drooping ears are dominant in dogs over erect ears, what genotype split can be expected? - in detail
In the study of canine genetics, understanding the inheritance patterns of physical traits is essential for breeders and geneticists. One such trait is ear shape, specifically whether ears are drooping or erect. Drooping ears are often observed to be dominant over erect ears in many dog breeds. This means that a dog only needs to inherit the dominant allele for drooping ears from one parent to exhibit the drooping phenotype.
To determine the expected genotype split, we must consider the possible genotypes resulting from a cross between dogs with different ear shapes. Let's denote the dominant allele for drooping ears as "D" and the recessive allele for erect ears as "d." A dog with drooping ears can have either a homozygous dominant genotype (DD) or a heterozygous genotype (Dd). A dog with erect ears must have a homozygous recessive genotype (dd).
When breeding a dog with drooping ears (genotype DD or Dd) to a dog with erect ears (genotype dd), the offspring's genotypes can be predicted using a Punnett square. If one parent is homozygous dominant (DD) and the other is homozygous recessive (dd), all offspring will inherit the dominant allele from the DD parent and the recessive allele from the dd parent. Thus, all offspring will have the genotype Dd and will exhibit drooping ears. The genotype split in this case is 100% Dd.
If the parent with drooping ears is heterozygous (Dd) and the parent with erect ears is homozygous recessive (dd), the offspring can have either the genotype Dd or dd. The expected genotype split is 50% Dd (drooping ears) and 50% dd (erect ears). This is because each offspring has a 50% chance of inheriting the dominant allele from the Dd parent and a 50% chance of inheriting the recessive allele from the dd parent.
In summary, the genotype split in the offspring depends on the genotypes of the parents. When one parent is homozygous dominant (DD) and the other is homozygous recessive (dd), all offspring will have drooping ears with the genotype Dd. When one parent is heterozygous (Dd) and the other is homozygous recessive (dd), the offspring will have a 50% chance of having drooping ears (genotype Dd) and a 50% chance of having erect ears (genotype dd). Understanding these inheritance patterns is crucial for breeders aiming to produce specific ear shapes in their litters.