MBG Chapter 13 DNA mutation and Repair Flashcards
What is a mutation?
The process by which the change to genetic material occurs
What is a mutant?
An organism that exhibits a novel phenotype (usually by mutation)
What type of mutations are there?
Changes in chromosome number and structure
Point mutations or changes at specific sites in a gene
What are the characteristics of mutations?
All sources of genetic variation
Mutations occur in all organisms
recombination mechanisms rearrange genetic variability into new gene combinations
Natural selection preserves the combination best adapted to the existing environment
What is somatic mutation?
Only occur in the descendants of the cell but not transmitted into progeny
What is germinal mutation?
occurs in gametes and will be passed down to the progeny
What is spontaneous mutation?
Occur without a known cause due to inherent metabolic errors of unknown agents in the environment
What is induced mutation?
Result from exposure of organism to mutagens
What is the frequency of spontaneous mutation?
Doesn’t happen often because there are mechanisms that keep mutations away
What are silent mutations?
no effect on the phenotype of the organism
What is a neutral mutation?
A change to a similar amino acid (Alanine to Glycine- both have similar chemical properties)
What are the two types of mutations that impairs function?
Missense and non sense
What is a missense mutation?
Function is impaired by amino acid change
What is nonsense mutation?
function is impaired by premature termination
What is a frameshift mutation?
Insertions or deletions that disrupt the translation reading frame
