Mutations Flashcards
multicellular organisms have two types of mutations,
name them :
-somatic mutations
-germ-line mutations
Alterations of DNA nucleotide sequence are of two types;
(1) point mutations-mutations of single genes
(2)chromosomal mutations- changes in arrangements of chromosomal DNA segments
transitions definition;
base changes to the same type of base
transversions
base changes to different types of bases
insertion
mutations in which extra base pairs are inserted into a new place in the DNA
delection
mutations in which a selection of DNA is lost/deleted
frameshift
since protein-coding DNA is divided into codons, insections and delections can alter the ORF
rearrangements
duplications, inversions and translocations
what is genetic variation?
-a SNP (single nuclectide polymorphism) is a change in which a single base in DNA differs from the usual base at that position
complete loss of protein causes?
loss-of-function
reduction of proteins’ ability to work causes?
gain-of-function
haploinsufficency definition?
-one copy is not enough
- defective gene interfers with function of ‘wild type’ copy
how do point mutations occur?
through mistakes during DNA replication or by environmental mutagens
DNA can break and reform causing 4 types of mutations;
1-delections
2-duplications
3-inversions
4-translocations
what are two environmental causes of DNA damage and repair?
-radiation
-carcinogens
