Lesson 1.2: Genetic Mutations

What are mutations?

these are any heritable change in the DNA that may have different consequences to an organism or its descendants

What causes mutations?

errors in DNA replication, recombination, or repair can cause changes in local DNA sequences or large-scale genome rearrangements

What are gene mutations?

these are changes in a single nucleotide, the insertion or deletion of one or more bases, or the rearrangement of larger sections of DNA

What are chromosomal mutations?

these are changes in the structure or number of entire chromosomes

What are mutagens?

these are agents that can induce mutations in the genetic material of an organism

What are chemical mutagens?

these are naturally occurring or synthetic chemicals that can cause mutations, which include base analogues, alkylating agents, deaminating agents, and intercalating agents

What are physical mutagens?

these induce mutations through physical means, thus directly damaging the DNA structure or interfering with the processes involved in DNA replication and repair, which includes ionizing radiation and ultraviolet radiation

What are environmental mutagens?

these are common pollutants and carcinogens in the environment that can cause mutations, which includes polycyclic aromatic hydrocarbons (PAH) and heterocyclic amines (HCAs)

What is a point mutation?

this type of gene mutation involves a change in a single base pair within the DNA sequence

What is a frameshift mutation?

this type of gene mutation involves the insertion or deletion of one or more base pairs

What is silent mutation?

this is a type of point mutation which results in a synonymous codon

What is nonsense mutation?

this is a type of point mutation which results in an early stop codon

What is a missense mutation?

this is a type of point mutation which results in a different amino acid

What is a frameshift mutation by insertion?

this is when a additional base pairs are inserted, which results a shift to the right and a different amino acid being coded

What is a frameshift mutation by deletion?

this is when one or more base pairs are lost, which results in a shift to the left and a protein missing one or two amino acids