Question

two plants are heterozygous for seed shape and have round seeds. if the two plants are crossed, what is the probability that the offspring will have wrinkled seeds?
25 percent
50 percent
75 percent
100 percent

Explanation:

Step1: Identify Genotypes

Heterozygous for seed shape (round is dominant, wrinkled recessive) means genotype \( Rr \) for both plants.

Step2: Set Up Punnett Square

Cross \( Rr \times Rr \). The Punnett square has four cells: \( RR \), \( Rr \), \( Rr \), \( rr \).

Step3: Determine Phenotypes

• \( RR \), \( Rr \), \( Rr \): round (dominant)
• \( rr \): wrinkled (recessive)

Step4: Calculate Probability

Wrinkled (\( rr \)) occurs 1 out of 4 times. \( \frac{1}{4} = 25\% \).

Answer:

25 percent