chapter 8 flashcards

Transformation

The uptake of free DNA from the environment by a bacterial cell.

Transduction

The transfer of bacterial DNA from one bacterium to another by a bacteriophage.

Conjugation

A process where bacteria transfer DNA through direct contact, often involving a plasmid.

Plasmid

A small, circular DNA molecule that is separate from the bacterial chromosome and can replicate independently.

Hfr strain

A strain of bacteria where the F plasmid is integrated into the bacterial chromosome, allowing for the transfer of chromosomal DNA.

Transposon

Segments of DNA that can move around to different positions within a genome, also known as 'jumping genes'.

Base substitution mutation

A mutation where one nucleotide base is replaced by another, potentially altering protein synthesis.

Silent mutation

A mutation that changes a nucleotide but does not change the amino acid or function of the protein.

Missense mutation

A mutation that results in a different amino acid being incorporated into a protein.

Nonsense mutation

A mutation that results in a premature stop codon, leading to a truncated and often nonfunctional protein.

Excision repair

A DNA repair mechanism that removes damaged nucleotides and replaces them with the correct ones.

SOS response

A cellular response to extensive DNA damage, enabling bacteria to replicate their DNA even with errors but often producing mutations.

DNA polymerase proofreading

The process by which DNA polymerase checks and corrects mistakes in nucleotide incorporation during DNA replication.

Mutagen

An agent that causes genetic mutation, such as radiation or chemicals.

Thymine dimer

A type of DNA damage caused by UV light, resulting in covalent bonding of adjacent thymine bases.

Horizontal gene transfer

The transfer of genes between organisms in a manner other than traditional reproduction.

Induced mutation

A mutation that occurs due to external factors, like chemical exposure or radiation.

Frame shift mutation

Mutations that occur when nucleotides are added or deleted, altering the reading frame of the gene.