Gene Mutations and DNA repair

Mutation

a change in the DNA sequence that can alter a genes function or product

Somatic Mutation

a mutation that occurs in a body (non-reproductive) cell; it only affects that individual not the offspring

Germline Mutation

a mutation that occurs in a reproductive cell and can be passed onto offspring

Point Mutation

a mutation in one nucleotide, identity of nucleotide changes

Silent Mutation

change in nucleotide that does not change amino acid specified by codon

Missense Mutation

change in the nucleotide that changes amino acid specified by codon

Nonsense Mutation

change in nucleotide that results in early stop codon

Frameshift Mutation

addition or deletion of a nucleotide

Evolutionarily Beneficial mutation

mutation that improves survival or reproduction

Neutral Mutation

a mutation that has no effect on survival or reproduction

Deleterious Mutation

a mutation that harms survival or reproduction

Evolutionary Fitness

the ability of an organism to survive and produce offspring compared to others in the population

Spontaneous Mutations

mutations that occur naturally during DNA replication or cell processes, without external cause

Induced Mutations

mutations caused by external factors, such as chemicals or radiation

Pyrimidine Or Thymine Dimers

when UV light causes two neighboring thymine bases to bind together, distorting the DNA and blocking replication

Proofreading

a process where DNA polymerase checks and corrects errors during DNA replication

Nucleotide Excision Repair (NER)

A repair system that removes a short stretch of damaged DNA and replaces it with the correct sequence using the undamaged strand as a template

Double Stranded break (DSB) Repair

Repair of DNA breaks that cut across both strands

Homologous Recombination Repair (HRR)

A DSB repair method that uses an undamaged, identical DNA sequence as a template to fix the break accurately

Non-Homologous End-Joining (NHEJ)

A DSB repair method that directly joins broken DNA ends together, often causing small insertions or deletions