Gene Mutations and DNA Repair

These flashcards summarize key concepts related to gene mutations and DNA repair mechanisms based on lecture notes.

What is a mutation?

A process that causes a change in DNA or chromosome structure.

What are somatic mutations?

Mutations that occur in body cells except gametes and are not passed to offspring.

What are germline mutations?

Mutations that occur in gametes and can be passed on to offspring.

Which mutations are more influential in evolutionary biology?

Germline mutations, as they can be passed on to offspring.

What is a point mutation?

A mutation in one nucleotide that can change the identity of that nucleotide.

What is a silent mutation?

A mutation that does not change the phenotype.

What is a missense mutation?

A mutation that changes the phenotype by altering one amino acid in the protein.

What is a nonsense mutation?

A mutation that results in an early stop codon, stopping translation prematurely.

What is a frameshift mutation?

A mutation caused by the addition or deletion of a nucleotide, changing the entire downstream code.

What causes mutations?

Mutations can be caused by spontaneous errors in replication or induced by agents like UV radiation.

What is nucleotide excision repair (NER)?

The process that removes and replaces damaged nucleotides, such as thymine dimers.

What is the effect of the mutation causing sickle-cell anemia?

It causes red blood cells to become sickle-shaped due to a missense mutation in the β globin gene.

What is homologous recombination repair (HRR)?

A repair process where homologous DNA is used as a template to fix double-stranded breaks.

What is non-homologous end joining (NHEJ)?

A repair mechanism that rejoins double-stranded breaks without a template.