Mutations Flashcards
1
Q
what is a mutation
A
a permanent change in sequence of base pairs
2
Q
what causes mutations
A
- mistakes which escape proof-reading function
- changes in the environment - toxins in food, radiation, chemical exposure
3
Q
what are germ cells
A
reproduction, sperm or egg cells
4
Q
what do mutations in germ cells cause
A
- can lead to inherited diseases
- mutation in a single base out of three can cause loss in protein function and decrease fitness
- all children of sufferer will carry mutation
5
Q
what are somatic cells
A
all other cells in the body
6
Q
what does somatic cell mutations cause
A
- this mutation gives a rise to cancer
- mutations accumulate in cells with age
- more than one gene needs to be mutated a single cell before it is cancerous
7
Q
what are carcinogens
A
all agents cause cancer
8
Q
what can carcinogens also cause
A
mutations. (mutagens x-rays and chemicals)
9
Q
what are chemical carcinogens either
A
- direct acting- few directly attack DNA
- Indirect- largest group, activated in detoxification
10
Q
what causes detoxification
A
cytochrome P-450, ENZYMES IN LIVER ADD CHEMICAL GROUPS to allow chemical breakdown
11
Q
what is deamination
A
the loss of an amino group from cytosine and C->T change
12
Q
what is deprivation
A
loss of base pair
13
Q
how are thymine dimers formed
A
result from cross linking 2 adjacent thymine by UV Light
