Question

a. in laboratory mice, gray coat color (g) is dominant over albino coat color (g). cross a female gg with a male gg and answer the questions that follow:

1. how many possible genotypes are there among the offspring?
2. how many possible phenotypes are there among the offspring?
3. what percentage of the offspring are gray?
4. what percentage of the offspring are albino?
5. what color is the female parent?
6. what color is the male parent?
7. what is the phenotypic ratio of gray coat color to albino coat color?

Explanation:

Step1: Determine gametes

The female \(Gg\) can produce gametes \(G\) and \(g\). The male \(gg\) can produce gametes \(g\) and \(g\).

Step2: Create Punnett square

	\(g\)	\(g\)
\(g\)	\(gg\)	\(gg\)

Step3: Analyze genotypes

The genotypes are \(Gg\) and \(gg\). So there are \(2\) possible genotypes.

Step4: Analyze phenotypes

Since \(G\) (gray) is dominant over \(g\) (albino), \(Gg\) is gray and \(gg\) is albino. So there are \(2\) possible phenotypes.

Step5: Calculate percentage of gray

Out of \(4\) offspring, \(2\) are \(Gg\) (gray). Percentage \(=\frac{2}{4}\times100\% = 50\%\)

Step6: Calculate percentage of albino

Out of \(4\) offspring, \(2\) are \(gg\) (albino). Percentage \(=\frac{2}{4}\times100\% = 50\%\)

Step7: Determine parental colors

Female is \(Gg\), so gray. Male is \(gg\), so albino.

Step8: Calculate phenotypic ratio

Gray (\(Gg\)) : Albino (\(gg\)) \(= 2:2=1:1\)

Answer:

1. \(2\)
2. \(2\)
3. \(50\%\)
4. \(50\%\)
5. Gray
6. Albino
7. \(1:1\)