Biology Exam Review: DNA, RNA, and Gene Regulation

A set of flashcards covering key vocabulary and concepts related to DNA, RNA, mutations, and gene regulation in biology.

Frameshift Mutation

Insertion or deletion of base pairs that shifts the reading frame of downstream codons, changing many amino acids.

DNA Replication

The process by which DNA makes a copy of itself before cell division, involving the separation of strands and synthesis of new complementary strands.

Codon

A three-nucleotide sequence on mRNA that codes for a specific amino acid.

Operon

A group of genes regulated together, often including a promoter and an operator.

Repressor Protein

A molecule that binds to the operator of an operon to block transcription.

Inducible Operon

An operon that is usually off but can be turned on in response to an inducer.

Corepressor

A small molecule that cooperates with a repressor protein to turn off transcription.

RNA Polymerase

The enzyme that synthesizes RNA from a DNA template during transcription.

Exon

Coding sequences in mRNA that remain after splicing.

Intron

Non-coding sequences in pre-mRNA that are removed during splicing.

tRNA

Transfer RNA that carries amino acids to the ribosome during protein synthesis.

Anticodon

A three-nucleotide sequence on tRNA that is complementary to a codon on mRNA.

Stop Codon

A codon that signals the end of translation; examples include UAA, UAG, and UGA.

Semiconservative Replication

The method of DNA replication in which each new DNA molecule consists of one original and one new strand.

Lysogenic Cycle

The viral replication cycle in which the viral DNA integrates into the host genome and can remain dormant.

Bacteriophage

A virus that specifically infects bacteria.

Messenger RNA (mRNA)

A type of RNA that carries the genetic information from DNA to the ribosome for protein synthesis.

Primase

An enzyme that synthesizes a short RNA primer to initiate DNA replication.

DNA Ligase

An enzyme that connects Okazaki fragments and seals gaps in the sugar-phosphate backbone.

Mutation

A change in the DNA sequence that can lead to changes in protein function.

Antiparallel Strands

In DNA, the two strands run in opposite directions—one from 5' to 3' and the other from 3' to 5'.