A mutation in a single gene may cause a major change in the body ...

Question

A mutation in a single gene may cause a major change in the body of a fruit fly, such as an extra pair of legs or wings. Yet it probably takes the combined action of hundreds or thousands of genes to produce a wing or leg. How can a change in just one gene cause such a big change in the body?

Accepted Answer

Hello everyone and welcome to today's video. So given the D. N. A strand here, which of the following is considered a substitution mutation. So basically we have to look at these strands which were created from the original one and determine which one incurs a substitution mutation. Remember that a substitution mutation is the substitution of a single base pair? Anything other than this will not be a substitution mutation. Now let's begin by answer choice B. Here. As we can see, there's going to be two base pairs that are going to be different because we need to only have one pair to be different in order for a substitution mutation to have taken place. We're going to cancel this out. Then we have answer choice C. Looking at the length of these two strands, we can already tell that something was out of here in this case. It's going to be here at the beginning. So these three base pairs were added, there were not substituted. So we're going to also cancel this because it is not a substitution mutation. Then we have answer choice D. As we can see again, the strand is much shorter. So what happened here? Well, these middle base pairs here were eliminated. That's why the strand is shorter. Again, we're going to cancel this out because an elimination does not incur a substitution mutation. This all leaves us with answer choice. A If we look at this new strand, we can see that the only thing that is going to be different is this base pair here, which is should be this one here. Here we have a warning and here we have a sight unseen. So the entire strands are exactly the same one, except by this single nucleotide that was substituting this wanting Because of this. This is going to be the perfect example of a substitution mutation, and we're going to highlight it as a final answer to our question. I really hope this helped you, and I hope to see you on the next video.

A mutation in a single gene may cause a major change in the body of a fruit fly, such as an extra pair of legs or wings. Yet it probably takes the combined action of hundreds or thousands of genes to produce a wing or leg. How can a change in just one gene cause such a big change in the body?

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