Question

this passage describes the ear type trait in rats: some rats have dumbo ears, which are larger and rounder than normal ears. dumbo ears are also set on the sides of the rats head instead of on the top. the word dumbo comes from the name of a cartoon elephant whose ears had a similar appearance. in a group of rats, some individuals have normal ears and others have dumbo ears. in this group, the gene for the ear type trait has two alleles. the allele for dumbo ears (e) is recessive to the allele for normal ears (e). this punnett square shows a cross between two rats. punnett square with rows e, e and columns e, e: top - left ee, top - right ee, bottom - left ee, bottom - right ee what is the probability that a rat produced by this cross will be homozygous recessive for the ear type gene? (in %)

Explanation:

Step1: Identify homozygous recessive genotype

Homozygous recessive is $ee$.

Step2: Count total and target genotypes

Total genotypes: 4 ($EE, Ee, Ee, ee$). Target ($ee$): 1.

Step3: Calculate probability percentage

$\text{Probability} = \frac{\text{Number of } ee}{\text{Total genotypes}} \times 100\% = \frac{1}{4} \times 100\%$

Answer:

25%