Three independently assorting genes (A, B, and C) are known to control the following biochemical pathway that provides the basis for flower color in a hypothetical plant:
Three homozygous recessive mutations are also known, each of which interrupts a different one of these steps. Determine the phenotypic results in the F₁ and F₂ generations resulting from the P₁ crosses of true-breeding plants listed here:
colorless (aaBBCC) × green (AABBcc)

Question

Three independently assorting genes (A, B, and C) are known to control the following biochemical pathway that provides the basis for flower color in a hypothetical plant:

Biochemical pathway showing flower color progression: colorless to yellow to green to speckled via genes A, B, and C.

Three homozygous recessive mutations are also known, each of which interrupts a different one of these steps. Determine the phenotypic results in the F₁ and F₂ generations resulting from the P₁ crosses of true-breeding plants listed here:

colorless (aaBBCC) × green (AABBcc)

Accepted Answer

Hi everyone. Let's take a look at this practice problem Together. If we cross a red and tall flower big a little a. Big B. Little B. With a red and short flower. Big A big a little B. Little B. What is the probability of producing red flowers? So we need to determine how many red flowers there will be when we cross these two parents and we can see from the parents that the red flowers are dominant and the red A. Lil is represented by Big A. So how many offspring are going to be red? Well, red flowers in this case can either be homos, I guess dominant represented by big A. Big A. Or they can be hetero ziggy's dominant represented by big a little A. We can simplify this problem a bit. We're only asked about the probability of red flowers and not anything about the height of the plant. So not anything about whether the plant is tall or short. And because the color trait is independently determined from the high trait, we can do a punnett square using only the color trait and we don't have to determine across at all for the hype, a little is represented by the bees. So let's go ahead and do our punnett square and cross the parents. So we'll have a big a little a parent cross with a big a big a parent. And let's draw out the punnett square. We'll get the following results And we can see that 100% of the offspring will have at least one dominant lil for red flowers. So 100% of offspring are red, and C will be our correct answer. Alright, everyone. I hope you found this helpful, and I'll see you for the next practice problem.

Verified video answer for a similar problem:

Key Concepts

Independent Assortment of Genes

Biochemical Pathway and Gene Function

Genotypic and Phenotypic Ratios in Crosses