Three pairs of genes with two alleles each (A₁ and A₂,B₁ and B₂, ...

Question

Three pairs of genes with two alleles each (A₁ and A₂, B₁ and B₂, and C₁ and C₂) control the height of a plant. The alleles of these genes have an additive relationship: Each copy of alleles A₁, B₁, and C₁ contributes 6 cm to plant height, and each copy of alleles A₂, B₂, and C₂ contributes 3 cm.

What are the expected heights of plants with each of the homozygous genotypes A₁A₁B₁B₁C₁C₁ and A₂A₂B₂B₂C₂C₂.

Accepted Answer

Hey, everyone. Let's take a look at this question together, the size of the seeds of the sativum plant is controlled by one gene having four alleles. What is the number of possible genotypes for this plant? Is it answer choice? A 10 answer choice B 12, answer choice C 14 or answer choice D 16. Let's work this problem out together to try to figure out which of the following answer choices is the number of possible genotypes for this plant. So we want to determine the number of possible genotypes and to do so we are going to use a formula that is N multiplied by N plus one in parentheses, divided by two, where N equals the number of all. And in this case, we know that the size of the seeds of the plant is controlled by one gene that has four alleles. So N which is the number of alleles equals four. And so we take our formula and we plug in 44, N, so we have four, multiplied by four plus one in parentheses, all divided by two. And we go ahead and simplify so we have four, multiplied by five in parentheses. Divided by two, which equals 20 divided by two since four multiplied by five equals 20. And we end up with 10 as our final answer. So the number of possible genotypes equals 10, which means that answer choice A 10 is the correct answer because we know that the number of possible genotypes for this plant can be calculated by using the formula N multiplied by N plus one in divided by two where N equals the number of alleles. And in this case, the number of alleles is four. So we have four multiplied by four plus one in parentheses, divided by two, which gives us the final answer of 10. So answer choice A is the correct answer. I hope you found this video to be helpful. Thank you and goodbye.

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