Histone variant
A histone variant is a non-canonical histone protein that can replace a standard histone to give chromatin specialized properties.
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Chromatin remodeling
Chromatin remodeling changes nucleosome position or composition so DNA can become more or less accessible.
Histone modification
Histone modification is the chemical alteration of histone proteins that helps regulate chromatin structure and gene activity.
Insulator
A genetic insulator is a DNA regulatory element that helps separate neighboring gene-control regions.
Silencer
A silencer is a regulatory DNA element that helps reduce or shut off transcription of a target gene.
Gene expression
Gene expression is the process by which information in a gene is used to make a functional RNA or protein product.
Reaction norm
A reaction norm shows how a genotype produces different phenotypes across an environmental range.
Phenotypic plasticity
Phenotypic plasticity is the ability of one genotype to produce different phenotypes when conditions change.
Phenotype
A phenotype is the observable or measurable set of traits produced by an organism's genotype, environment, development, and life history.
Genotype
A genotype is the genetic makeup of an organism or the specific alleles it carries at one or more genetic locations.
Single-nucleotide variant
A single-nucleotide variant is a difference at one DNA base position, a small change that can be harmless, useful as a marker, or important for health.
Silent mutation
A silent mutation is a DNA change that does not alter the encoded amino acid sequence, often because the genetic code has synonymous codons.
Nonsense mutation
A nonsense mutation is a DNA change that turns an amino-acid codon into a premature stop signal, often shortening the resulting protein.
Missense mutation
A missense mutation is a DNA sequence change that alters a codon so a different amino acid is placed in a protein.
Frameshift mutation
A frameshift mutation is an insertion or deletion that changes how a coding sequence is grouped into codons, often altering every downstream amino acid.
Open reading frame
An open reading frame is a stretch of DNA or RNA that can be read as codons without an internal stop signal, making it a candidate protein-coding sequence.
Aminoacyl-tRNA synthetase
Aminoacyl-tRNA synthetases are enzymes that attach the right amino acids to the right tRNAs, making accurate translation possible.
Ribosomal RNA
Ribosomal RNA, or rRNA, is the structural and catalytic RNA at the heart of ribosomes, the cellular machines that translate mRNA into protein.
Messenger RNA
Messenger RNA, or mRNA, is the RNA copy of genetic information that ribosomes read to build proteins.
Transfer RNA
Transfer RNA, or tRNA, is the adaptor molecule that matches mRNA codons with amino acids during protein synthesis.
Codon
A codon is a three-nucleotide unit in DNA or RNA that tells the translation machinery which amino acid to add, or when to stop building a protein.
Attenuation
Attenuation is a gene-regulation strategy in which transcription is stopped early, often because a growing RNA folds differently as translation responds to nutrient levels.
Rho factor
Rho factor is a bacterial protein motor that helps terminate transcription by catching RNA polymerase on certain transcripts and releasing the RNA.
Sigma factor
A sigma factor is a bacterial transcription-initiation protein that helps RNA polymerase find the right promoters and start copying DNA into RNA.