Microbiology - Mutations & Genetic Exchange (L15-16)

A collection of flashcards covering key concepts related to mutations and genetic exchange in bacteria.

What are the main types of genetic exchange mechanisms in bacteria?

Transformation, Transduction, and Conjugation.

What is a mutation?

A change in the base sequence of the nucleic acid of an organism's genome.

What is a point mutation?

A change in a single base pair that can lead to an amino acid change or no change in a polypeptide.

What are deletions and insertions in the context of mutations?

Changes in DNA that cause frameshift mutations and often result in loss of gene function.

What is an auxotroph?

A mutant that cannot synthesize a compound required for its growth due to a mutation.

What are mutagens?

Chemical, physical, or biological agents that increase the mutation rate.

What is the importance of RecA protein in genetic recombination?

RecA protein facilitates homologous recombination by combining closely related DNA sequences.

What is the Ames test used for?

To measure mutagenesis by using histidine auxotrophs to determine the effect of chemicals on mutation rates.

What are the two life cycles of a temperate virus?

The lytic cycle, where new virions are produced, and the lysogenic cycle, where the virus integrates its genome into the host.

Define transformation in bacteria.

The uptake of 'naked' DNA directly from the environment into a bacterial cell.

What is transduction?

The process of DNA transfer mediated by a bacteriophage.

What happens during bacterial conjugation?

Transfer of genetic material via direct contact between bacterial cells through a pilus.

What are frameshift mutations?

Mutations caused by deletions or insertions that shift the reading frame of the genetic code.

What does SOS regulatory system do?

Activates DNA repair processes in response to DNA damage.

What is specialized transduction?

A rare event where specific bacterial genes are incorporated into a phage during its life cycle.

What is the mutation rate range per base pair?

Mutation rates are generally seen at 10–7 to 10–11 per base pair.