Question

what should you expect to observe if a pea plant that is homozygous dominant for a certain trait is crossed with a pea plant that is homozygous recessive for that trait?a. all of the plants in the f₂ generation will have the recessive trait.b. all of the plants in the f₁ generation will have the dominant trait.c. all of the plants in the f₁ generation will have a combination of the two traits.d. all of the plants in the f₂ generation will have the dominant trait.

Explanation:

Step1: Define parent genotypes

Let the dominant allele = $D$, recessive allele = $d$.
Homozygous dominant parent: $DD$; Homozygous recessive parent: $dd$

Step2: Find F₁ generation genotypes

Each parent passes one allele. All F₁ offspring get $D$ from dominant parent and $d$ from recessive parent, so all F₁ = $Dd$.

Step3: Determine F₁ phenotype

$D$ (dominant) masks $d$ (recessive), so all F₁ show dominant trait.

Step4: Analyze F₂ generation (F₁ self-cross)

Cross $Dd \times Dd$. Offspring genotypes: $DD$ (25%), $Dd$ (50%), $dd$ (25%). Phenotypes: 75% dominant, 25% recessive.

Answer:

B. All of the plants in the F₁ generation will have the dominant trait.