The control of gene expression Flashcards
What are 6 types of gene mutation?
addition, deletion, substitution, inversion, duplication and translocation of bases
What is addition?
Addition of one or more nucleotides
What is deletion?
Removal of one ore more nucleotides
What is substitution?
Nucleotide is replaced by another nucleotide
What is inversion?
Sequence of bases is separated and attached in reverse order
What is duplication?
One or multiple bases is repeated
What is translocation?
A piece of DNA breaks off and doesn’t reattach to itself or its homologous pair
Do all mutations lead to a non-functioning protein?
Some mutations may only affect a single codon, changing a single amino acid in a protein, therefore the protein may remain functional.
What type of mutation leads to non-functioning proteins?
insertions and deletions lead to frameshift mutations - changes all codons and amino acids downstream mutation
What is mutation rate affected by?
mutagenic agents such as alpha and gamma rays, UV light - can be chemical, biological or physical.
What are stem cells?
Undifferentiated cells that can express all of their genes and divide by mitosis
What is cell differentiation?
When cells become specialised for different functions
What is a totipotent stem cell?
Can divide and differentiate into any type of cell
