Mutation Flashcards
Chapter 4
What is a mutation?
A heritable change in an organism’s DNA sequence that may lead to altered phenotype.
What is a mutant?
An organism with a mutation, potentially showing a change in phenotype.
What is the wild type?
The phenotype most commonly observed in nature.
What is a point mutation?
A mutation that affects a single base in the DNA sequence.
What are the classes of point mutations?
Substitution, insertion, and deletion.
What is a substitution mutation?
A mutation where one base is replaced by another.
What is an insertion mutation?
The addition of one or more bases into the DNA sequence.
What is a deletion mutation?
The removal of one or more bases from the DNA sequence.
What is a silent mutation?
A mutation that does not alter the amino acid sequence of the protein.
What is a missense mutation?
A mutation that results in a different amino acid being incorporated into the protein.
What is a conditional mutation?
: A missense mutation whose effects are apparent only under certain conditions.
What is a nonsense mutation?
A mutation that converts an amino acid codon into a stop codon, producing a truncated protein.
What causes a frameshift mutation?
Insertions or deletions not in multiples of three, altering the reading frame of mRNA.
Why are frameshift mutations problematic?
hey change every amino acid after the mutation and often result in nonfunctional proteins.
What are spontaneous mutations?
Mutations caused by errors during DNA replication.
