Question

show the cross between two heterozygous round plants.

1. establish the genotypes

of the parents: ×

1. set up the square.

1. determine the phenotypic percentages:

__ % are round
__ % are wrinkled.

Explanation:

Step1: Determine Parent Genotypes

Let \( R \) represent the dominant allele for round seeds and \( r \) represent the recessive allele for wrinkled seeds. Heterozygous round plants have the genotype \( Rr \). So the parents' genotypes are \( Rr \times Rr \).

Step2: Set Up Punnett Square

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

Step3: Determine Phenotypes

• Genotypes \( RR \), \( Rr \), \( Rr \) (3 out of 4) show the round phenotype (since \( R \) is dominant).
• Genotype \( rr \) (1 out of 4) shows the wrinkled phenotype.

To find percentages:

• Round: \( \frac{3}{4} \times 100 = 75\% \)
• Wrinkled: \( \frac{1}{4} \times 100 = 25\% \)

Answer:

s:

1. \( Rr \) × \( Rr \)
2. (Punnett Square as above)
3. 75% are round; 25% are wrinkled.