Question

genetic research quick check
in mice, the gene for tail length has two alleles. a long tail is dominant to a short tail. if a long - tailed mouse that is heterozygous mates with a short - tailed mouse, what are the chances of having offspring with short tails? (1 point)
○ 75%
○ 50%
○ 25%
○ 100%

Explanation:

Step1: Define allele notation

Let $L$ = dominant long tail allele, $l$ = recessive short tail allele.

Step2: Identify parent genotypes

Heterozygous long-tailed mouse: $Ll$; short-tailed mouse: $ll$

Step3: Set up Punnett square

$$\begin{array}{c|cc} & L & l \\ \hline l & Ll & ll \\ l & Ll & ll \\ \end{array}$$

Step4: Calculate short-tailed offspring ratio

Count $ll$ genotypes: 2 out of 4 total. Ratio = $\frac{2}{4} = 0.5$

Answer:

B. 50%