Genetics - Mutations Flashcards
What is a mutation? Mutations collected over time cause changes to the ______? Some are spontaneous, others are a reaction w a ______.
Small-scale change in nucleotide sequence of DNA. Changes genome. May be caused by reaction w mutagen.
Examples of mutagens?
radiation: gamma, x-rays, microwaves
chemicals: tar in cigs
Mutations could have no effects (_______) or catastrophic events.
benign
What percent of human DNA is non-coding? A point mutation that has no effect on the functioning genome is called a ______ mutation.
98.5%, silent
Mutations in the coding regions could also be _______. Ex. a point mutation to GAA converts the codon to GAG but both code for Gly
silent
What is a mis-sense mutation?
A point mutation that changes a codon so that a different protein is specified
A gene can tolerate a few amino acid ______ before biological function is changed. What kind of mutation is this?
changes. Missense (single diff protein is produced)
What type of mutation coverts a codon that specifies an amino acid into a stop codon? How long is the protein? What are the effects?
Nonsense, short, catastrophic (non-functional protein)
What are the two types of frameshift mutations?
Addition or deletion of a single nucleotide that changes the entire reading frame of mRNA
The deletion of a single nucleotide (A, T, C or G) changes all the codon __________ from the change.
downstream.