Topic 8 - Genetic Mutations Flashcards
What is a mutation?
Mutations are changes in the base sequence of DNA that can occur during DNA replication or due to external factors. These change can affect the structure and function of protein and, in some cases, the phenotype of an organism.
What is a substitution mutation?
A single base is replaced by another.
What is a silent mutation?
No change in the amino acid due to the degenerate nature of the genetic code.
What is a missense mutation?
A different amino acid is produced, potentially altering the protein’s structure and function.
What is a nonsense mutation?
The mutation introduces a stop codon, resulting in a truncated, non-functional protein.
What is an insertion mutation?
One or more nucleotides bases are added to the sequence.
What is a deletion mutation?
One or more nucleotide bases are removed from the sequence.
What is a frame shift?
Altered reading frame of the genetic code, which typically leads to a completely different and non-functional protein.
What is a duplication mutations?
One or more bases are repeated, leading to a frameshift and abnormal protein production.
What is an inversion mutation?
A segment of DNA is removed, reversed, and reinserted into the same location. This alters the order of bases, potentially affecting the amino acids coded.
What is a translocation mutation?
A segment of DNA from one chromosome is removed and inserted into another chromosome. Often results in major changes to the organisms phenotype and can disrupt gene regulation.
What is a spontaneous mutation?
Errors during DNA replication, which occur naturally.
What are induced mutations?
Radiation: UV or ionising radiation can break DNA strands or alter bases.
Chemicals: mutagens like benzene or abestos can cause base change or DNA damage.
Viruses: some viruses insert their genetic material into the host DNA, causing mutations.
What are neutral mutations?
No effect on the organisms survival or reproduction.
What are harmful mutations?
Lead to diseases or decreased survival.
What are beneficial mutations?
Provide an advantage in certain environments, driving evolution.
