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 do we know that molecular gradients in the egg of Drosophila exist?

Video transcript

Hello, everyone. Let's look at our next question. It says which the following M R N A s is in high concentration in the future. And here end of the Drosophila embryo. Well, when we think about the establishment of directionality in embryos, we say the future anterior end, we're thinking about maternal effects genes. And we look at our answer. Choices, we can eliminate choice B Coddle and Choice D hunchback jeans because these are segmentation genes. They come in later in the process after you already have that directionality established in the embryo and you're looking to begin the process of segmentation. So choice, we're now between choice a nano's and choice C by coid. These are maternal effects jeans and the bike coi gene is one of those Marnie's that's expressed in the egg even prior to fertilization. And these M RNA transcripts are stored in the egg concentrated in the anterior end of the egg. So after fertilization in the early embryo, the translation of the NHS leads to a concentration gradient in which higher amounts of the bike oid protein are present in the anterior end of the embryo that establishes that directionality of the early embryo. So by coid is going to be our answer here. Choice c choice A Nanosys not correct. That is a maternal effect gene, but the product of the translation of the nano's gene is concentrated in the posterior end of the embryo rather than the interior. That's why that's not our correct answer. So we can eliminate choice A. So again, which the following M R and S is in high concentration in the future and your end of the Drosophila embryo, and that's choice C by coid. See you in the next video.