Question

two heterozygous black mice are crossed. in these mice, black fur (b) is dominant over white (b). what are the expected genotypes and phenotypes of their offspring?
label the punnett square with the parents genotypes. click on a genotype box to open the keypad. use the shift button to toggle between letter cases.

Explanation:

Step1: Determine parents' genotypes

Heterozygous means having two different alleles. So parents' genotypes are \( Bb \).

Step2: Set up Punnett square

Parents: \( Bb\times Bb \).

	B	b
b	\( Bb \)	\( bb \)

Step3: Analyze genotypes

Genotypes: \( BB:Bb:bb = 1:2:1 \).

Step4: Analyze phenotypes

Since \( B \) (black) is dominant, \( BB \) and \( Bb \) show black, \( bb \) shows white. Phenotypes: black:white \( = 3:1 \).

Answer:

Genotypes: \( 1\ BB:2\ Bb:1\ bb \). Phenotypes: \( 3\) black : \( 1\) white.