Question

Question #1. Chinchillas are small, furry South American rodents. They were originally brought to the United States from Chile in 1918 and raised for their fur, and have become increasingly popular as cage pets. They come in a variety of colors, but the most common is gray. In chinchillas, gray fur is dominant to violet. If both parents are HETEROZYGOUS, what is the probability in their offspring of:

being homozygous dominant? ________%

being heterozygous? ________%

being homozygous recessive? ________%

having violet fur? ________%

Answer 1

Gray fur is dominant represented by allele G

Violet fur is recessive represented by g

Parents are heterozygous so their genotype would be Gg. They would produce gamete with eithe G or g with equal probability.

On crossing the parents, the result is expected to be similar to Mendelian monohybrid cross result.  

25% homozygous dominant

50% heterozygous

25% homozygous recessive

Those having homozygous recessive genotype would have violet fur. So 25 % would have violet fur.