Which of the following provides the strongest evidence for the co...

Question

Which of the following provides the strongest evidence for the conservation of tool-kit genes?
a. Bicoid moved from one fly embryo into the posterior of another fly embryo causes the formation of two head regions.

b. Mutation of an unrelated gene in another species of fly has a similar effect to mutation of bicoid in Drosophila.

c. A mouse Hox gene can be used to take over the function of a mutated Drosophila Hox gene.

d. Sheep can be cloned by fusing a differentiated adult cell with an enucleated egg.

Accepted Answer

Welcome back. Here's our next question. Walter Gehring discovered the conservation of the toolkit gene by using the eyeless gene, he put the mouse's eyeless gene into the fruit fly. What happened to the fruit fly in his experiment? Well, the terminology here can be a little bit confusing. Um The gene is called eyeless because the result of a mutation in it is the lack of eyes in the developing animal. So the eyeless gene, its name is Pax six. So if we think of it as a pack 16, it's responsible for the development of eyes. So what he did in his experiment was he replaced the fruit fly, Pack six or Eilis with the mouse version. Now if we think about this mouse eye and a fruit fly, I are extremely different. So one might expect that those fruit flies would have defective eyes or something would go wrong. However, the result of his experiment was that the fruit flies had normal fly eyes. So this shows us that these packs six genes for the development of eyes. They are highly conserved from an ancestral species. So they're kind of the there's an ancestral prototype for I that's then been specialized in different species. But that basic gene is highly conserved among very very different species. So let's look at our answer choices. And we see that choice C. Does reflect the experimental result. The fruit fly had normal eyes. So again our other answer choices here are choice A. The fruit fly became eyeless. That did not occur. Choice B only one of the eyes function normally. No or choice D The genes got rejected by the fly system. No. The genes were expressed as totally normal fruit fly eyes. So that's showing the high conservation of that toolkit gene, a toolkit gene meaning basic jeans for anatomical development. So we think of the hawks genes, but the packs gene is another um toolkit gene there, in this case for the development of eyes. See you in the next video.

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