a pea plant that has round seeds has the genotype rr. it is crossed with a pea plant that has wrinkled seeds and the genotype rr. what is the probability that the offspring will have wrinkled seeds?
LectureNotes said a pea plant that has round seeds has the genotype rr. It is crossed with a pea plant that has wrinkled seeds and the genotype rr. What is the probability that the offspring will have wrinkled seeds?
Answer: To determine the probability that the offspring will have wrinkled seeds, let’s first correct a potential misunderstanding in the question. Typically, in Mendelian genetics, the allele for round seeds (R) is dominant over the allele for wrinkled seeds (r). However, the information provided states that both plants have the genotype “rr,” which would actually mean both plants have wrinkled seeds since “rr” is the recessive genotype for wrinkled seeds.
Given that both parent plants have the genotype “rr” (wrinkled seeds), we can set up a Punnett square to determine the genotype of the offspring.
Punnett Square Analysis:
- Parent Genotypes: Both parents have the genotype “rr.”
- Gametes: Each parent can only pass on the “r” allele.
Let’s set up the Punnett Square:
| r | r | |
|---|---|---|
| r | rr | rr |
| r | rr | rr |
Offspring Genotypes:
- All possible genotypes of the offspring are “rr.”
Phenotype of Offspring:
- Since “rr” is the genotype for wrinkled seeds, all offspring will have wrinkled seeds.
Probability Calculation:
- The probability that the offspring will have wrinkled seeds is 100%.
Therefore, the probability that the offspring will have wrinkled seeds is 100%.