Chapter 7:DNA Mutation, DNA repair and Transposable Elements Flashcards
Chromosomal mutations?
changes involving whole chromosomes
Point Mutations?
a change of one or a few base pairs. It may change the phenotype of the organism if it occurs within the coding region of a gene or in the sequences regulating the gene.
Gene mutations?
mutations which affect the function of genes. It can alter the phenotype by changing the function of a protein.
Mutation??
the process by which the sequence of base pairs in a DNA molecule is altered. It may result in a change to either a DNA base pair or a chromosome
A cell with a mutation is called what?
a mutant cell
There are two classifications of mutations based on the type of cell they occur in, what are they?
Somatic mutation and germ-line mutation
Somatic mutation?
- mutation happening in a somatic cell
- the mutant characteristic affects only the individual in which the mutation occurs is not passed on to the succeeding generation.
Germ-line mutation?
- a mutation in the germ line of sexually reproducing organisms
- may be transmitted by the gametes to the next generation producing an individual with the mutation in both its somatic and germ line cells.
Mutation rate?
the probability go a particular kind of mutation as a function of time
ex: # of mutations per nucleotide pair per generation
ex: number per gene per generation
Mutation frequency?
the number of occurrences of a particular kind of mutation
What are the two types of point mutations?
- Base pair substitutions
2. Base pair insertions or deletions
Base pair substitutions??
change from one base pair to another in DNA
What are the two general types of Base Pair substitutions?
- Transition mutation
2. Transversion mutation
Transition mutation???
a mutation from one purine-pyrimidine base pair to the other purine-pyrimidine base pair.
(A-T to G-C)
Transversion mutation??
a mutation form purine-pyrimidine base pair to a pyrimidine-purine base pair.
( G-C to C-G)
Where do point mutations USUALLY occur. Is that a good thing?
- noncoding region
- yes …bad if in coding region obv
Base pair substitutions in protein coding genes are also defined in terms of their effects on aa sequences in proteins. What are the four types of mutation effects?
- Missense Mutation
- Nonsense Mutation
- Neutral Mutation
- Silent Mutation