In this chapter, we have focused on large-scale as well as the inter- and intracellular events that take place during embryogenesis and the formation of adult structures. In particular, we discussed how the adult body plan is laid down by a cascade of gene expression, and the role of cell–cell communication in development. Based on your knowledge of these topics, answer several fundamental questions:

How have we discovered that specific genes control development in an organism like Drosophila?

Video transcript

Welcome back. Let's look at our next question. Which of the following genes controls the development of specific segments in the Drosophila embryo. Well, here we're talking about development segments. We're talking about the various earliest, the very earliest stages of embryonic development. So we want to look at these exotic genes and we'll just put up a list of these guys and those start with the maternal effects genes that established the basic directionality of the embryo by means of concentration gradients. So they established the anterior posture, dorsal and ventral orientation of the embryo, their maternal effects genes since they come from the expression of genes that are present in the egg prior to fertilization, those are regulate the expression of the segmentation genes. Um And those we see, we've got three types here, gap, jeans, pair rule genes and segment polarity genes. But when we look at our answer choices, those three types are not among our answer choices, we just have the basic types of psychotic genes as answer choices. So segmentation genes are those genes that control the development of the embryo into basic segments. Starting with just the formation of the segments, then formation of segments that occur in pairs and then finally establishing polarity within each segment. And then finally, you have the action of the home idiotic selector genes which determine the identity of each segment and then direct the sort of cellular destiny, the structural development of which anatomical structures each segment will form. So when we look at our answer choices, we have maternal, a maternal effect, jeans be segmentation genes, see homoerotic selector genes or d both and be. And if we didn't guess from the name, we want to look here at segmentation genes, would your choice be? Because those are the genes that overall direct the development of those segments going from the embryo that just has basic directionality and starting to subdivide it into those segments. So again, which of the following genes control the development of specific segments in the embryo choice B segmentation genes. See you in the next video.