Inheritance Trait

Question

The trank is a hypothetical diploid animal having 22 chromosomes in each of its somatic cells. Just like in humans, the female is the homogametic sex—all of her somatic cells contain 2 sex chromosomes that are identical (XX). The male somatic cells contain an X and a Y sex chromosome. The following traits have been described in this animal: Presence of toe hairs (T gene: T = toe hairs present, t = naked toes) Eye color (E gene: E = deposition of color, e = no deposition of color; R gene: R = red, r = pink) Hair curliness on knuckles (C gene: C = very curly, c = straight) Freckles (F gene: F = freckles present, f = no freckles) In parentheses, after each of the traits listed above, you can see which genes have been linked to that trait and the alleles for each of those genes.

Based on this information, please answer the following questions: Two hairy-toed tranks are crossed. Three-fourths of the progeny are hairy toed; one-fourth of the progeny have naked toes. In a separate cross, a hairy toed trank is crossed with a naked toed trank, resulting in half of the progeny being hairy toed and half having naked toes. According to these crosses, which allele is the dominant one? Explain your answer.

A trank with freckles is crossed with a trank having no freckles. All of the resulting female trank progeny have freckles while all of the male trank progeny have no freckles. Write out the genotypes of the two parents and explain how these progeny ratios are possible.

A cross was made between a trank homozygous for very curly hair on her knuckles and a male trank homozygous for straight hair on his knuckles. All of the progeny had hairy knuckles but, in every case, the hair curliness was not very curly and was not straight either. The scientist recording the progeny phenotypes reported that the hair curliness was kind of in between that of both parents. What is the simplest explanation for the phenotype of the progeny?



The following cross was made: RrEe x rrEe. What are the possible genotypes of the progeny? What are the possible phenotypes of the progeny and the ratios of those phenotypes?

Answer 1

See the google doc below:

https://docs.google.com/document/d/1j4OccZ2yx7an4JtbKBXnTtxjBMu5Fk8QRzx102Ql11Y/edit?usp=sharing