Cellular control

Mutations

Changes in the DNA base sequence caused by mutagens.

Mutagens

Agents like UV, X-rays, gamma rays, radiation, and chemicals that cause changes in DNA sequences.

Point mutations

Small-scale mutations affecting a single base in DNA, including substitution, addition, and deletion.

Frameshift mutation

Caused by addition or deletion of bases, disrupting the triplet code reading during translation.

Nonsense mutation

Mutation where a codon changes into a stop codon, leading to premature termination of protein synthesis.

Missense mutation

Mutation where one amino acid is substituted for another due to a change in the DNA sequence.

Chromosomal mutations

Large-scale mutations like deletion, duplication, and translocation that affect chromosome structure and gene function.

Transcription factors

Proteins involved in transcribing DNA into RNA, regulating gene expression.

Lac operon

A group of genes controlled by the same regulatory mechanism in prokaryotes, involved in lactose metabolism.

Heterochromatin

Tightly packed DNA around histones, inhibiting transcription; can be converted to euchromatin for gene expression.

Post-transcriptional control

Processes like splicing, capping, and tailing of mRNA to produce mature mRNA for translation.

Post-translational control

Modifications to polypeptides after translation to alter protein function and structure.

Homeobox genes

Regulatory genes controlling body development, cell positioning, mitosis, and apoptosis; highly conserved across species.

Hox genes

Subset of homeobox genes found in animals, regulating body development, cell positioning, and responses to stimuli.