Intro + Methods Flashcards
What are the two general phases of life?
Build up: Embryogenesis,adolescence adulthood
Gradual functional decline: Later adulthood
Who were the IVF pioneers?
- Steptoe, Robert Edwards and Jean Purdy
**Jean Purdy was the first person to observe and describe the human blastocyst stage embryo
What is the epigenesis theory?
- Aristotle
Embryos develop from microscopic entity that lacks any detailed form but somehow becomes more complex, acquires new structures within it as it grows i.e. complexity emerges gradually
What is the Pre-formation theory?
embryo begins life as a perfect microscopic form of what it will become. Proposed by Malphigi. Drew and presented to the world their descriptions of sperm.
Describe the principles of the cell theory
- Proposed in 19th century
- All organisms are composed of one or more cells
- The cell is the most basic unit of structure,function and organisation in all organisms
- All cells arise from pre-existing living cells
What is the Germ plasm determinants theory and who proposed it?
Weismann
- All germ cells contain a full array of determinants of cell identity that then become parcelled out into different lineages within the developing embryo i.e. muscle cell determinants go in to muscle lineages
What is the key thing to remember with mutants and gene expression?
all genes have the mutation but only the cell that require that protein the mutation codes for will be affected
What is paracrine communication?
transmitted from one cell to another which isn’t immediately adjacent over a diffusion gradient
what is autocrine communication?
cell signals to itself at the same time its signalling to other cells
what is juxtacrine communication?
cells physically adjacent contact via surface proteins which remain on the surface (e.g. notch signalling)
What is meant by cell signalling competence?
CELLS MUST HAVE THE CAPACITY TO PERCEIVE THE SIGNAL AND RESPOND APPROPRIATELY
What is the difference between an instructive and a permissive signal?
instructive= initiates new program
permissive = provides favorable environment for a specific program i.e. makes it easier for another cell to bind
Ways at which control of gene expression can be exerted?
Production of mRNA
Processing/stability of mRNA
Production of proteins
Activity of proteins
Why are transcription factors called cis-regulators?
they bid close to genes that they regulate , bind to enhancers upstream of the specific gene
What is Morphogenesis and what does it need?
Cell/tissue movements and changes in cell behaviour that give the developing embryo or organ its shape in 3D
Needs:
- Cell adhesion
- Cell migration
- Cell death
- Cell shape