Genetic variation Flashcards
Form of variation without mutation?
Crossing over
Term for chromosomes after crossing over?
Recombinant
Mutations?
Heritable changes in genetic material not due to genetic recombination
Can mutations in gametes be passed on?
Very small chance but not 0
Point mutations?
Changes in single base/small piece of genetic material
Purines?
A & G
Pyrimidines?
C and T
Transitions?
A to G or C to T
Transversion?
purine to pyrimidine
Transversions or transitions most common?
Transitions
Which quality of the genetic code means some changes don’t alter the amino acid?
It is redundant
Highly redundant amino acid?
Arginine
Amino acid only coded for by ATG?
Methyline
Non-synonymous change?
Amino acid changed
Synonymous change?
Amino acid doesn’t change
Most likely change?
Synonymous
Least likely change?
Removal of a start/addition of a stop codon
Mutation with serious consequences for protein?
Removal of a start/addition of a stop codon
Do mutations happen more often at synonymous site?
No - they’re just more likely to be tolerated & maintained in population at a synonymous site
Do all non-synonymous changes have serious consequences for the protein?
Some are minor & can be tolerated
Phenotype for sickle cell anaemia? (4)
- abnormal beta chains
- haemoglobin stick together & form chains
- sickle shaped deoxygenated red blood cells
- reduced life expectancy
Genotype for sickle cell anaemia? (3)
- amino acid 6
- base position 2
- GGA to GTA (Glu to Val)
What type of DNA do INDELs typically occur at?
Repetitive sections of DNA
Are INDELs common in genomes?
Yes
Why are INDELs common in genomes?
Only small proportion of genomes genes - repetitive DNA tends not to be in genes
Minisatellites?
10 to 15 base pairs in length
Microsatellites?
1 to 5 base pairs in length
Genetic fingerprinting? (3)
- sections of DNA that vary in size
- apply current
- small sections migrate further in agarose gel than larger
What can genetic fingerprinting be used for?
paternity tests, forensics, conservation genetics