Question

1. in pea plants, round (r) is dominant to wrinkled (r). a heterozygous female is crossed with a wrinkled male. make a punnett square to determine the possible offspring.

a. what are the possible genotypes of the offspring?

b. what are the possible phenotypes of the offspring?

c. what is the probability of having an offspring that is round?

d. what is the probability of having an offspring that is homozygous?

Explanation:

Step1: Determine the genotypes of the parents

The heterozygous female has the genotype \( Rr \). The wrinkled male has the genotype \( rr \) (since wrinkled is recessive, it must have two recessive alleles).

Step2: Set up the Punnett square

The female can produce two types of gametes: \( R \) and \( r \). The male can only produce \( r \) gametes.

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

Step3: Analyze genotypes (for part a)

From the Punnett square, the possible genotypes are \( Rr \) and \( rr \).

Step4: Analyze phenotypes (for part b)

Since \( R \) (round) is dominant: \( Rr \) has a round phenotype and \( rr \) has a wrinkled phenotype.

Step5: Calculate probability of round (for part c)

Out of 4 squares in the Punnett square, 2 have \( Rr \) (round). Probability \( P=\frac{2}{4}=\frac{1}{2} \).

Step6: Calculate probability of homozygous (for part d)

Homozygous genotypes are \( rr \). There are 2 \( rr \) out of 4. Probability \( P = \frac{2}{4}=\frac{1}{2} \).

Answer:

a. \( Rr, rr \)
b. Round, Wrinkled
c. \( \frac{1}{2} \)
d. \( \frac{1}{2} \)