ZOO 3603C - Exam 1 Questions And Answers (Verified And Updated)

ZOO 3603C - Exam 1 Questions And Answers (Verified And Updated) How has developmental biology impacted modern medicine? - answerIVF (in vitro fertilization) teratology - study of congenital abnormalities Birth defects, prenatal diagnosis cloning What is regulation? - answerthe ability to respecify cells so that the removal of cells destined to become a particular structure can be compensated for by other cells producing that structure Who discovered Regulation? - answerRoux What is determination? - answerthe second and irreversible stage of a cell or tissue commitment in which the cell or tissue is capable of differentiating autonomously, even when placed in a non neutral environment What "proved" determination - answerWeisman and Conklin Experimented with snail eggs and found that the germ layers were determined because macho-1 was only found in early mesodermal cells and could not be reversed Shown to only be true in certain organisms What enables us to be able to do IVF and prenatal diagnosis? - answerHuman embryo is regulative. Therefore, you can take one of the eight human blastula cells and it is not detrimental to development. What did Hartsoeker believe about development? - answerHe was a preformationist. He looked at his sperm through a lens and believed that a tiny man was sitting in the acrosome. The yolk allows the fetus to grow What did Driesh believe? - answerEntelechy A vital force drives development What did Child believe? - answerMetabolic gradients determined the different embryonic laters No molecular bio to back it up though Who discovered the organizer and how? - answerSpemann discovered the organizer by grafting it to the other side of a xenopus embryo -Wolpart also proposed the organizer! What are examples of the organizer? - answerDorsal lip of the blastopore (xenopus) Zone of Polarizing Activity (organizer in chick limb bud) Notochord (organizes DV axis in spinal chord) How do the organizers work? - answerCells interpret what to do based on their position in a field. Position determined by concentration of morphogen. What is "in situ" hybridization? - answerA technique used to localize mRNA Show's how morphogens are produced in a gradient and diffuse What are common morphogens? - answerShh FGFs Wnts BMP (activin) Nodal RA - retinoic acid What stops the morphogen from diffusing across an entire embryo? - answerAntagonists switch the signal off What commits the germ cells to their fate early? - answercytoplasmic determinants (germ plasm/mRNA) How do germ cells arise in C. eleganS, drosophila, xenopus, and salamanders/mammals? - answerC. elegans - polar granules Drosophila - pole plasm Xenopus - germ plasm Salamander/Mammal - induction What allows induction of germ cells in mammals? - answerBMPs (bone morphogenic protein), sox2, nanog, oct4 What happens after germ cells are induced in mammals? - answerProduced in yolk sac, move to abdominal cavity, then genital ridges What determines male germ cells? - answerSRY gene on Y chromosome kicks in