Question

1. set up the punnett squares for each of the crosses listed below. round seeds are dominant to wrinkled seeds.

rr x rr
what percentage of the offspring will be round?
rr x rr
what percentage of the offspring will be round?

Explanation:

Step1: Analyze \(Rr\times rr\)

• Parent 1 (\(Rr\)) can produce gametes \(R\) and \(r\).
• Parent 2 (\(rr\)) can produce gametes \(r\) and \(r\).
• Punnett square:

	\(R\)	\(r\)
\(r\)	\(Rr\)	\(rr\)

• Genotypes: \(Rr:rr = 2:2=1:1\)
• Since \(R\) (round) is dominant over \(r\) (wrinkled), the proportion of round - seeded offspring (\(Rr\)) is \(\frac{2}{4}=\frac{1}{2}\)

Step2: Analyze \(Rr\times Rr\)

• Parent 1 (\(Rr\)) can produce gametes \(R\) and \(r\).
• Parent 2 (\(Rr\)) can produce gametes \(R\) and \(r\).
• Punnett square:

	\(R\)	\(r\)
\(r\)	\(Rr\)	\(rr\)

• Genotypes: \(RR:Rr:rr=1:2:1\)
• The proportion of round - seeded offspring (\(RR + Rr\)) is \(\frac{1 + 2}{4}=\frac{3}{4}\)

Answer:

• For \(Rr\times rr\), \(50\%\) of the offspring will be round.
• For \(Rr\times Rr\), \(75\%\) of the offspring will be round.