mutation Flashcards
what is a mutagen
something that causes a permanent change to DNA
three types of mutations
- electromagnetic radiation
- chemicals
- naturally occuring
what is ectromagnetic radiation
electromagnetic radiation involves 3 dangerous ionising radiation that can produce free radicals ehich cause breakage in DNA.
what are the 3 top dangerous ionising radiation?
- UV, gamma
- x-rays
- gamma rays
how does elctromagnetic radiation caus mutations
direct:
ionising radiation frees electrons from DNA molecules. The High energy electrons can damage DNA.
indirect:
When electrons pass through cells, they interact with water and release free radicals. Radicals are highly reactive and will break strands of DNA leading to deletions, partial chromosome loss, cross-linking of DNA with itself etc. This interferes with protein synthesis.
example of mutation caused my electromagnetic radiation
skin cancer
chemicals
chemicals that will cause mutations if there is a high frequency or exposure over long periods of time
naturally occuring
exposure to microbes, plnat and animlas that can cause mutations
types of mutations
- point mutations
- chromosomal mutations
what is point mutation?
chnage in only 1 nucleotides
two types of point mutations
- substitution
- frameshift
what is substitution point mutation?
1 nucleotide is swapped out for another
what is frame shift point mutation?
mutation causing a dowmstream shift in codon reading sequence
- insertion
- deletion
what are the effects from point mutations
- silent:
no chnage to amino acid - missense:
change in amino acid creates non-functional protein - nonsense:
change in nuceotife codes for stop codon causing non-functional protein
chromosomal mutation
A mutation that affects the structure or number of chromosomes in a cell which causes genetic disorders
what are the four tpes of chromosomal mutation?
- deletion
- inversion
- translocation
- duplication
deletion
section of chromosome is removed
inversion
section of chromosome is removed, rotated 180 and reunserted
translocation
section of 1 chromosome is moved to a non-homologous chromosome (pair of chromosomes that are structues the same and carries the same gene
duplication
sectio of chromosome is doubles an dinserted increasing the number of genes
what are the two effects of chomosomal mutations
- aneuploidy
- polyploidy
what is aneuplody?
having a full extra chromosomes or missing a full chromosomes
what is polyploidy?
- more than normal set of chromosomes
what is somatic mutations?
mutations that occur in the body cells rather than in reproductive cells.
what is the location of somatic mutations?
somatic cells which are body cells - lungs, skin, liver
what is the cause of somatic mutations?
mutation occurs during interphase before mitosis
is somatic mutations heredity?
no
what are the effects of somatic mutations?
individual = development of a tumour over time
Examples of somatic mutations
Skin cancer
Brain tumour
Liver cancer
What is germ line mutations
Mutation that occur in the reproductive cells
Is germ line mutations heritary?
Yes, it is passed on to offspring, affecting every cell in the offsprings body
Example of germline mutations
Cystic fibrosis
Down syndrome
Breast cancer
what is the impact of germ line mutations?
it can lead to inherited genetic consitions and may affect future generations
coding mutations
mutations which occur in the coding dna which usually affect the type of amino acids in the polypeptide chain, resulting in an abnormal protein end-product
what does mutations in a coding dna cause?
abnormal protein end product
example of a disease caused by the mutation in coding dna
sickle cell anaemia
example of a disease caused by the mutation in coding dna
sickle cell anaemia
what is non-coding DNA?
non-coding mutations are dna’s that do not code for proteins
what are the three types of non-coding DNA?
- dna used for replicating e.g tRNA
- regulatory sequence
- repetitive dna
what is regulatory sequence DNA?
dna that controles the amount of protein produces
example of a disease that is caused from a mutation in a non-coding DNA?
Lung cancer
- mutations is caused in Regulatory sequence dna causing the exessive protein produce resulting in tumours
what is a gene pool?
Gene pool is the total collection of alleles for all genes in a population
Do gene pools chnage overtime?
yes
What are the reasoning of why gene pools change?
- gene flow
- gene drift
- mutations
- selection pressures
what is gene flow?
movement of allele population
what is gene drift?
Radom events occurring within the population
E.g deaths and births
What is selection pressures?
Any external factors which effects an organisms ability to survive
E.g temperature and food
What are the causes of genetic variation?
- Crossing over
- Independent assortment
- Random segregation
What are the three types of effect of mutations?
- Neutral effect
- Harmful effect
- Beneficial effect
