Development II Flashcards
Define fate map and what it tells us
Answers the question “if left undisturbed in the embryo, what will this cell become” ?
Part of descriptive embryology, does not invovled any cell manipulation.
Define specification map and what it shows us
Specification map tells us what happens to a cell if it is isolated from its neighbours. Thus this tells us what a cell
Define determined
A cell is said to be determined if it still develops according to its fate after being re-located to a new location within the cell.
Define competence
Competence is the type of
Define induction
Induction is the abi
Define and explain descriptive embryology
descriptive embryology is allowing cells to develop and observing what structures they form.
State three key structures of the egg
Ectoderm
Endoderm
Mesoderm
What is the ectoderm
Skin and nervous tissue
What is the endoderm
Lungs and digestive tissue
What is the mesoderm
Notochord, muscles and blood.
List the key stages in development of a embryo
Zygote B cells stage Blastula Gastrula Neurula
What is the Xenopus laevis
Frog
Very important model organsim for developmental biologists,
Explain the features of Xenpous Laevis that makes it such an ideal model organism for developmental biologists
i) Has very large oocytes
ii) frog oocyte has inherent asymmetry.
What does the specification map show?
The specification map describes which cells are commited to a certain fate.
What does the equivalency of the fate and specification map tell us
If the fate and specification maps match it shows that cells rely on cell-cell communication. (This is regulative development)
Define and explain regulative development
Cells rely on cell-cell communication.
Define and explain mosaic development
Mosaic development is the autonomous development of the cells fate. Fate is determined by cytoplasmic factors contained within the cell itself called cytoplasmic determinants.
These cells will form a fated structure even if transported to a new location
Explain why non-equibalency of the fate map and specification map is evidence for mosaic development
Cells undergoing mosaic development decide their own fate due to asymmtetric distribution of cytoplasmic determinants (inside themselves). Thus these cells form fated structure even if transported to a new location. When specification maps and fate maps do not match, this means communication between cells is not required.
When does regulative development typically occur
During the early gastrulation stage when cells are induced to form different structures according to cell-cell signalling interactions in a specific region of the embryo.
Outline the Organizer experiment 1924
Spemann-Mangold organizer is a group of cells responsible for the induction of neural tissues during embryonic development in amphibians.
What does the spemann mangold organizer refer too?
Refers to the population of cells in a frog embryo that establishes the dorsal-ventral and AP axis
State the role of the organizer cells, and where they are located in the frog embryo
i) S-M organizer cells are located in the dorsal-blastopore lip.
ii) f(x) is to induce neural tissues during embryonic development.
Dorsal
Towards the back and away from the stomach
Ventral
Towards the stomach. Ventral surfaces include chest, abdomen, shins, palms and soles.
