COMPLETE THE FOLLOWING QUESTIONS (15 points) (3 points) A new phenotype of mouse
ID: 268239 • Letter: C
Question
COMPLETE THE FOLLOWING QUESTIONS (15 points) (3 points) A new phenotype of mouse has been discovered -short-tails. You have been given a short-tailed mouse and do not know a tailed mouse with a long-tailed mouse. Multiple crosses of your short-tailed mouse to long-taile mice produces 27 long-tailed mice and 25 short-tailed mice. When you cross these short-tailed progeny with each other, you get 31 short-tailed mice and 11 long-tailed mice. What was the genotype of the original short-tailed mouse? What is the genotype of the long-tailed mice used in this breeding experiment? Short tailed mouse Long-tailed mouse: 1. nything about its genotype. You decide to cross your shoExplanation / Answer
Case1:
Short tailed× long tailed
It produced short and long tailed progeny in 1:1 ratio (appropriate).
Case2:
Short tailed×short tailed
It produces short and long tailed in 3:1 ratio.
From case 2, we can infer that genotype of short tail should be heterozygous , say Aa.
Thus , short tail should be dominant trait.
Hence, in case 1,
Genotype of short tail mice should be Aa. (Heterozygous).
Genotype of long tailed mice should be aa. (Homozygous recessive).