Differentiation&variation Flashcards
What is epigenetics
Heritable chnage in gene function without chnage to DNA base sequence
How does methylation of DNA affect gene transcription
Addition of CH3 to cytosine base
Increased methyl groups inhibit transcription factors and enzymes needed for transcription
In what ways does epigenetics control gene expression
Tightly wound / unwound histone proteins which get chemically altered my methyls/acétyles to alter gene expression
What is a stem cell
A undiffentiated cell thag can give rise to specialised cells that can divide to produce more stem cells
What is a pluripotent cell
Unspecialised cell that can differentiate to give rise to almost any type of cell in the body, excluding totipotent cell
What are totipotent cells
Totipotent cells can give rise to/differentiate to become any cell/extra embryonic tissues
Difference between totipotent & pluripotent cells
Pluripotent cells can’t give rise to all cells / extra embryonic cells
Totipotent cells can give rise to other totipotent cells
Totipotent can give rise to a full human, pluripotent can’t
How do stem cells give rise to specialised cell [EQ STYLE]
- Idea of appropriate stimuli(chemical/hormone)
- Activation of some genes
- Activated genes are transcribed / mRNA made only at active genes
- mRNA translated on ribosomes
- Protein made
- Which determines cell structure /function
Advantages of using stem cells from patient instead of donor?
- no risk of rejection
- no immunosuppressant drugs
- less chance of infection
polygenic ?
a characteristic showing continuous variation
caused my multiple genes at different loci
sex linked disorder?
a disorder caused by faulty gene located on X/Y chromosome so it’s more likely in one gender than the other
