Mutations Flashcards
What is a mutation?
Permanent change in DNA of a cell
What is point mutation?
Change in nucleotide sequence
What is chromosomal mutation?
Change in gene position
Are mutations in somatic cells passed down in generations?
No
Is cancer caused by somatic mutations?
Yes
Are germ line mutations passed down generations?
Yes
What are the types of point mutation?
Base pair substitution (silent, missense, nonsense(stop codon))
Base pair deletion/insertion (extra AA, frameshift missense, immediate nonsense(stop codon))
What causes sickle cell anaemia?
A single nucleotide substitution in haemoglobin has a large negative effect
What is spontaneous cause of mutation?
through DNA replication - inherent instability in DNA
What is indices cause of mutation?
Chemical eg X-ray or UV
What are the three types of chemical agents that act of DNA and can result in mutations?
Chemicals that resemble DNA based but pair incorrectly when incorporated with DNA
Chemicals that’s remove the amino group from adenine or cytosine OR add hydrocarbon groups to nucleotide bases
Intercalating agents
What are the types of physical agents which cause mutations?
Ionisation
Ultraviolet radiation
What are 3 main causes of cancer?
Carcinogens
UV
Smoking
Is benzpyrene a mutagen?
No but it is converted to one in the body
What does the Ames rest identify?
Potential mutagens
