In this chapter, we have focused on sex differentiation, sex chromosomes, and genetic mechanisms involved in sex determination. At the same time, we found many opportunities to consider the methods and reasoning by which much of this information was acquired. From the explanations given in the chapter, you should answer the following fundamental questions?

How do we know whether or not a heteromorphic chromosome such as the Y chromosome plays a crucial role in the determination of sex?

Video transcript

Hey everyone. Let's take a look at this question together. What is the default sex development pathway in animals? In the absence of a Y chromosome? So we know that throughout embryonic development the S. R. Y. Gene on the why chromosome causes the development of masculine rates. And so in the absence of this Y chromosome, that means that we do not have that S. R. Y. Gene. And so the embryonic gonads will grow into ovaries and take on feminine features, which means that answer choice, a female is the correct answer, because when we have that absence of that Y chromosome which the S. Ry gene is present on, that means we have the absence of that S. R. Y. Gene, which causes the development of masculine traits. And so the default sex development pathway in animals without that gene is female. So answer choice A is the correct answer. I hope you found this video to be helpful. Thank you and goodbye.