BIO - F - the control of gene expression

mutations, stem cells, control of transcription and translation (epigenetics), cancer,

what is a mutation

change in the DNA sequence that can alter the expression of genes an occur during replication.

what are the types of mutations

deletion

addition 

substitution 

inversion

duplication 

translocation 

what is deletion

when an AA is removed from the sequence - causes frameshift

what is addition

when an AA is added to the sequence - causes frameshift

what is substitution

when an AA in the sequence is replaced by another AA can change the expression of one gene, but doesn’t cause frameshift 

what is inversion

a section of DNA sequence is reversed

what is duplication

section of chromosome is repeated

what translocation 

is the movement of a chromosome segment to a new position on the same or another chromosome 

what are stem cells

non-specialised cells that can differentiate into various cell types and make more of themselves 

where can stem cells be found 

meristem in plants - roots and shoots 

bone marrow - animals

what are the four different stem cells (in terms of differentiation ability)

unipotent

pluripotent

totipotent

multipotent

what does unipotent mean

can only differentiate into one type of cell

what does multipotent mean

can differentiate into a few cell types

what does pluripotent mean

can differentiate into almost any cell type, except for placental cells.

(placenta and umbilical chord)

what does totipotent mean

can differentiate into any body cell, including placenta and umbilical cord cells.