When solving a genetics problem involving the crossing of two plants, it's essential to understand the inheritance patterns that result from crossing different genotypes. Here's a detailed, step-by-step explanation of what to expect when a pea plant that is homozygous dominant for a certain trait is crossed with a pea plant that is homozygous recessive for that trait:
1. Define Terms:
- Homozygous dominant: having two identical dominant alleles (BB).
- Homozygous recessive: having two identical recessive alleles (bb).
2. Initial Cross:
- The plant that is homozygous dominant (BB) for the trait is crossed with the plant that is homozygous recessive (bb) for the same trait.
3. Gametes Formation:
- The homozygous dominant plant (BB) will produce gametes with the dominant allele (B).
- The homozygous recessive plant (bb) will produce gametes with the recessive allele (b).
4. Formation of F1 Generation:
- When these two plants are crossed, each gamete from the dominant plant (B) will pair with each gamete from the recessive plant (b).
5. Genotypes of F1 Generation:
- The offspring, or F1 generation, will all have the genotype Bb (heterozygous).
6. Phenotype of F1 Generation:
- Since the dominant allele (B) masks the presence of the recessive allele (b), all plants in the F1 generation will exhibit the trait associated with the dominant allele.
7. Conclusion:
- All plants in the F1 generation will have the dominant trait.
Given the question and the possible answers:
A. All of the plants in the [tex]$F_2$[/tex] generation will have the recessive trait. (Incorrect)
B. All of the plants in the F1 generation will have a combination of the two traits. (Incorrect)
C. All of the plants in the [tex]$F_2$[/tex] generation will have the dominant trait. (Incorrect)
D. All of the plants in the F1 generation will have the dominant trait. (Correct)
Therefore, the correct answer is:
D. All of the plants in the F1 generation will have the dominant trait.
