Imagine a situation in which a morphogen has its source at the posterior end of a Drosophila embryo. Every 100 µm from the posterior pole, the morphogen concentration decreases by half. If a cell required 1/16th the amount of morphogen found at the posterior pole to form part of a leg, how far from the posterior pole would the leg form? a. 100 μm b. 160 μm c. 400 μm d. 1600 μm

Video transcript

Hello everyone and welcome to today's video. So today we have that in flights frogs and checks gradients of blank determine the future Antara posterior and dorsal ventral access of the developing embryo. And so we're given certain terms here that we can choose this from. So let's begin by answer choice. A apoptosis. Remember that apoptosis is programmed cell death. This is in no way related to how the developing embryo is going to determine its ventral access is so we're going to cancel this out. Then we have androgens and these androgens are sex hormones. Here again in the question we're not talking about the determination of sex jet. So we're not going to select androgens as or answer. Then we have mutations and those mutations or agents of mutation or just molecules are going to speed up the process of making mutations happen in the D. N. A. This is in no way going to be associated with how the developing embryo is going to determine its future and the posterior and dorsal ventral axis is so we're going to cancel this out as well. And then we have Morfogen as our final answer. Now, Morfogen in case you forgot, I want to remind you exactly what they are. And there are these signaling molecules. The signaling molecules are actually present in the embryo and they spread from a region of tissue and they form these gradients. Remember that here in the question. They also talk about gradients and these gradients dictate the pattern of development. So the way that this work is a certain regions of tissue release signaling molecules in order to let other tissue know how to develop. So this is how the actresses are going to know how to develop in the embryo. So we're going to highlight answer choice B Morfogen as a final answer to our question. I really hope this video helped you, and I hope to see you on the next one.