Glossary
Verified educational definitions for chromatin, DNA, gene expression, epigenetics, and genetics. 181 terms shown.
A
- Accessible chromatin — Alias related to Chromatin accessibility: Chromatin accessibility describes how easily proteins can contact DNA within packaged chromatin.
- Acetylated histones — Alias related to Histone acetylation: Histone acetylation adds acetyl groups to lysines and often correlates with more accessible, active chromatin.
- Allele — An allele is an alternative version of a gene found at the same locus on homologous chromosomes.
- Anaphase — Anaphase separates sister chromatids toward opposite poles.
- Anticodon — An anticodon is the three-base tRNA sequence that base-pairs with an mRNA codon during translation.
B
C
- CDS — Alias related to Coding DNA: Coding DNA is sequence that specifies the amino-acid sequence of a protein via codons in mRNA.
- Cell — The cell is the basic unit of life; eukaryotic cells package their genome in a nucleus as chromatin.
- Cell cycle — The cell cycle is the ordered series of stages a cell passes through to grow and divide.
- Cell cycle chromatin — Alias related to Chromatin and the cell cycle: Chromatin organization changes across the cell cycle, from accessible interphase forms to condensed mitotic chromosomes.
- Cell nucleus — The nucleus is the eukaryotic organelle that houses chromosomal DNA and is the site of transcription.
- Central dogma — Teaching framework: DNA → RNA → protein information flow.
- Centromere — The centromere is the chromosome region where kinetochores assemble for spindle attachment during segregation.
- Chromatid — A chromatid is one copy of a duplicated chromosome; sister chromatids are joined before anaphase separation.
- Chromatin — Chromatin is the DNA–protein complex that packages eukaryotic genomes and helps regulate gene access.
- Chromatin accessibility — Chromatin accessibility describes how easily proteins can contact DNA within packaged chromatin.
- Chromatin and the cell cycle — Chromatin organization changes across the cell cycle, from accessible interphase forms to condensed mitotic chromosomes.
- Chromatin architecture — Alias related to Chromatin structure: Chromatin structure describes how DNA and histones are organized from nucleosomes to higher-order domains.
- Chromatin compaction — Chromatin compaction is the folding of DNA–protein fibers into denser forms, culminating in mitotic chromosomes.
- Chromatin complex — Alias related to Chromatin: Chromatin is the DNA–protein complex that packages eukaryotic genomes and helps regulate gene access.
- Chromatin condensation — Alias related to Chromatin compaction: Chromatin compaction is the folding of DNA–protein fibers into denser forms, culminating in mitotic chromosomes.
- Chromatin fiber — Alias related to Chromatin: Chromatin is the DNA–protein complex that packages eukaryotic genomes and helps regulate gene access.
- Chromatin function — Chromatin functions in packaging the genome, regulating access for transcription, and supporting replication and repair.
- Chromatin organization — Chromatin organization describes spatial and regional patterns of genome packaging in the nucleus.
- Chromatin remodeling — Chromatin remodeling uses specialized complexes to slide, eject, or restructure nucleosomes and change DNA access.
- Chromatin structure — Chromatin structure describes how DNA and histones are organized from nucleosomes to higher-order domains.
- Chromatin-remodeling complex — Chromatin-remodeling complexes are multi-protein machines that use energy to reposition or alter nucleosomes.
- Chromosome — A chromosome is an organized package of DNA and proteins that carries genetic information.
- Chromosome condensation — Chromosome condensation is the compaction of chromatin into discrete mitotic or meiotic chromosomes.
- Chromosomes — Alias related to Chromosome: A chromosome is an organized package of DNA and proteins that carries genetic information.
- Closed chromatin — Alias related to Chromatin accessibility: Chromatin accessibility describes how easily proteins can contact DNA within packaged chromatin.
- Coding DNA — Coding DNA is sequence that specifies the amino-acid sequence of a protein via codons in mRNA.
- Coding sequence — Alias related to Coding DNA: Coding DNA is sequence that specifies the amino-acid sequence of a protein via codons in mRNA.
- Codon — A codon is a three-nucleotide mRNA sequence that specifies an amino acid or a translation stop signal.
- Compact chromatin — Alias related to Heterochromatin: Heterochromatin is generally more compact, less accessible chromatin associated with reduced transcription.
- Complementary base pairing — Alias related to DNA base pairing: DNA base pairing pairs A with T and G with C, enabling complementary strands and accurate copying.
- Constitutive heterochromatin — Constitutive heterochromatin remains compact across most cell types and is often rich in repeats.
- Core promoter — Alias related to Promoter: A promoter is a regulatory DNA region where transcription machinery assembles to start transcription.
- CpG island — CpG islands are GC-rich genomic regions with elevated CpG density, often found near mammalian promoters.
- Cytokinesis — Cytokinesis divides the cytoplasm to produce two daughter cells.
D
- Deoxyribonucleic acid — Alias related to DNA: DNA stores genetic information as a sequence of nucleotide bases in a double helix.
- Diploid — Having two sets of homologous chromosomes.
- DNA — DNA stores genetic information as a sequence of nucleotide bases in a double helix.
- DNA base pairing — DNA base pairing pairs A with T and G with C, enabling complementary strands and accurate copying.
- DNA compaction — Alias related to DNA packaging: DNA packaging describes how long DNA molecules are folded with proteins to fit and function in cells.
- DNA helix — Alias related to Double helix: The double helix is the twisted-ladder structure of two complementary DNA strands.
- DNA methylation — DNA methylation is a chemical modification of DNA bases—commonly cytosine in CpG contexts—in many organisms.
- DNA mutation — A DNA mutation is a change in DNA sequence that can alter RNA and protein products or regulatory sites.
- DNA packaging — DNA packaging describes how long DNA molecules are folded with proteins to fit and function in cells.
- DNA repair — DNA repair pathways detect and correct DNA damage or replication errors to protect genome integrity.
- DNA replication — DNA replication copies the genome by using each strand as a template for a new complementary strand.
- DNA structure — DNA structure features a sugar-phosphate backbone and complementary base pairs forming a double helix.
- Dominance — Alias related to Dominant allele: A dominant allele is expressed in the phenotype even when only one copy is present in a heterozygote.
- Dominant allele — A dominant allele is expressed in the phenotype even when only one copy is present in a heterozygote.
- Double helix — The double helix is the twisted-ladder structure of two complementary DNA strands.
E
- Enhancer — An enhancer is a regulatory DNA element that increases transcription of a target gene, often from a distance.
- Epigenetic regulation — Alias related to Epigenetics: Epigenetics studies heritable gene-activity states that do not change DNA sequence.
- Epigenetics — Epigenetics studies heritable gene-activity states that do not change DNA sequence.
- Epigenome — The epigenome is the genome-wide set of epigenetic features such as DNA methylation and histone marks in a cell state.
- Euchromatin — Euchromatin is generally less compact, more accessible chromatin often enriched for active genes.
- Expression of genes — Alias related to Gene expression: Gene expression uses information in a gene to make a functional RNA or protein product.
F
G
- G1 phase — G1 is the first gap phase after mitosis/cytokinesis when the cell grows and performs normal functions before DNA replication.
- G2 phase — G2 is the second gap phase after DNA replication when the cell prepares for mitosis.
- Gene — A gene is a DNA segment that contains information for a functional product, typically an RNA or protein.
- Gene expression — Gene expression uses information in a gene to make a functional RNA or protein product.
- Gene mutation — Alias related to DNA mutation: A DNA mutation is a change in DNA sequence that can alter RNA and protein products or regulatory sites.
- Gene promoter — Alias related to Promoter: A promoter is a regulatory DNA region where transcription machinery assembles to start transcription.
- Gene regulation — Gene regulation controls when, where, and how much gene products are made.
- Gene silencing — Gene silencing is the stable reduction or shutdown of gene expression by regulatory mechanisms.
- Genes — Alias related to Gene: A gene is a DNA segment that contains information for a functional product, typically an RNA or protein.
- Genetic material complete set — Alias related to Genome: A genome is the complete genetic material of an organism or cell type under study.
- Genetic mutation — Alias related to Mutation: A mutation is a heritable change in DNA sequence that can create new alleles and affect phenotypes.
- Genome — A genome is the complete genetic material of an organism or cell type under study.
- Genome maintenance — Alias related to DNA repair: DNA repair pathways detect and correct DNA damage or replication errors to protect genome integrity.
- Genome organization — Alias related to Chromatin organization: Chromatin organization describes spatial and regional patterns of genome packaging in the nucleus.
- Genome packaging — Alias related to DNA packaging: DNA packaging describes how long DNA molecules are folded with proteins to fit and function in cells.
- Genome science — Alias related to Genomics: Genomics is the study of genomes using sequencing, comparison, and large-scale functional analysis.
- Genomic imprinting — Genomic imprinting causes certain genes to be expressed in a parent-of-origin-specific manner.
- Genomics — Genomics is the study of genomes using sequencing, comparison, and large-scale functional analysis.
- Genotype — A genotype is an organism’s genetic makeup at one or more loci—the alleles it carries.
H
- Haploid — Having one set of chromosomes.
- Heredity — Alias related to Inheritance: Inheritance is the transmission of genetic information from parents to offspring.
- Heterochromatin — Heterochromatin is generally more compact, less accessible chromatin associated with reduced transcription.
- Heterozygote — Alias related to Heterozygous: Heterozygous means having two different alleles at a locus (Aa in simple notation).
- Heterozygous — Heterozygous means having two different alleles at a locus (Aa in simple notation).
- Histone — A packaging protein that helps DNA form nucleosomes.
- Histone acetylation — Histone acetylation adds acetyl groups to lysines and often correlates with more accessible, active chromatin.
- Histone H1 — Histone H1 is a linker histone that binds linker DNA and helps stabilize higher-order chromatin folding.
- Histone H2A — Histone H2A is a core histone that pairs with H2B in the nucleosome octamer.
- Histone H2B — Histone H2B is a core histone that pairs with H2A in the nucleosome octamer.
- Histone H3 — Histone H3 is a core histone central to the nucleosome and rich in regulatory tail modifications.
- Histone H4 — Histone H4 is a highly conserved core histone that forms a tetramer with H3 in the nucleosome.
- Histone marks — Alias related to Histone modification: Histone modifications are chemical marks on histone proteins that help regulate chromatin behavior.
- Histone methylation — Histone methylation adds methyl groups to residues such as lysine; outcomes depend on site and context.
- Histone modification — Histone modifications are chemical marks on histone proteins that help regulate chromatin behavior.
- Histone proteins — Alias related to Histones: Histones are the core packaging proteins of chromatin that form the nucleosome octamer.
- Histones — Histones are the core packaging proteins of chromatin that form the nucleosome octamer.
- Homologous chromosomes — Homologous chromosomes are chromosome pairs with the same genes at corresponding loci, one from each parent.
- Homologs — Alias related to Homologous chromosomes: Homologous chromosomes are chromosome pairs with the same genes at corresponding loci, one from each parent.
- Homozygote — Alias related to Homozygous: Homozygous means having two identical alleles at a locus (AA or aa in simple notation).
- Homozygous — Homozygous means having two identical alleles at a locus (AA or aa in simple notation).
I
- Imprinting — Alias related to Genomic imprinting: Genomic imprinting causes certain genes to be expressed in a parent-of-origin-specific manner.
- Inheritance — Inheritance is the transmission of genetic information from parents to offspring.
- Interphase — Interphase is the G1, S, and G2 portion of the cell cycle when the cell grows and replicates DNA.
J
K
- Karyotype — A karyotype is a display of an organism’s condensed chromosomes arranged for analysis of number and structure.
- Karyotyping — Alias related to Karyotype: A karyotype is a display of an organism’s condensed chromosomes arranged for analysis of number and structure.
- Kinetochore — The protein structure assembled at the centromere for microtubule attachment.
L
M
- Meiosis — Meiosis is a two-division process that produces haploid cells and increases genetic variation.
- Meiotic division — Alias related to Meiosis: Meiosis is a two-division process that produces haploid cells and increases genetic variation.
- Mendelian genetics — Mendelian genetics describes inheritance patterns based on segregation and independent assortment of alleles.
- Mendelian inheritance — Alias related to Mendelian genetics: Mendelian genetics describes inheritance patterns based on segregation and independent assortment of alleles.
- Messenger RNA — Alias related to mRNA: Messenger RNA (mRNA) carries genetic coding information from DNA to ribosomes for translation.
- Metaphase — Metaphase aligns chromosomes at the metaphase plate with spindle attachments.
- Methylated histones — Alias related to Histone methylation: Histone methylation adds methyl groups to residues such as lysine; outcomes depend on site and context.
- Mitosis — Mitosis is nuclear division that segregates sister chromatids into two daughter nuclei.
- Mitotic division — Alias related to Mitosis: Mitosis is nuclear division that segregates sister chromatids into two daughter nuclei.
- mRNA — Messenger RNA (mRNA) carries genetic coding information from DNA to ribosomes for translation.
- MRNA processing — Alias related to RNA processing: RNA processing converts eukaryotic primary transcripts into mature RNAs through capping, splicing, and more.
- Mutation — A mutation is a heritable change in DNA sequence that can create new alleles and affect phenotypes.
N
- Non-coding DNA — Alias related to Noncoding DNA: Noncoding DNA does not specify protein amino-acid sequence but includes many functional regulatory and structural elements.
- Noncoding DNA — Noncoding DNA does not specify protein amino-acid sequence but includes many functional regulatory and structural elements.
- Nuclear organization — Alias related to Chromatin organization: Chromatin organization describes spatial and regional patterns of genome packaging in the nucleus.
- Nucleosome — The nucleosome is the basic repeating unit of chromatin: DNA wrapped around a histone octamer.
- Nucleosome core particle — Alias related to Nucleosome: The nucleosome is the basic repeating unit of chromatin: DNA wrapped around a histone octamer.
- Nucleosome occupancy — Alias related to Nucleosome positioning: Nucleosome positioning refers to where nucleosomes sit along DNA and how that placement affects access to sequences.
- Nucleosome positioning — Nucleosome positioning refers to where nucleosomes sit along DNA and how that placement affects access to sequences.
- Nucleosome remodeling — Alias related to Chromatin remodeling: Chromatin remodeling uses specialized complexes to slide, eject, or restructure nucleosomes and change DNA access.
- Nucleosome structure — Nucleosome structure details the histone octamer, wrapped DNA, and protruding histone tails.
- Nucleus — Alias related to Cell nucleus: The nucleus is the eukaryotic organelle that houses chromosomal DNA and is the site of transcription.
O
- Okazaki fragment — A short lagging-strand DNA piece synthesized during replication.
- Open chromatin — Alias related to Chromatin accessibility: Chromatin accessibility describes how easily proteins can contact DNA within packaged chromatin.
- Open chromatin regions — Alias related to Euchromatin: Euchromatin is generally less compact, more accessible chromatin often enriched for active genes.
- Open reading frame — A continuous codon sequence from start to stop that can encode protein.
P
- Phenotype — A phenotype is an organism’s observable traits resulting from genotype and environment.
- Promoter — A promoter is a regulatory DNA region where transcription machinery assembles to start transcription.
- Prophase — Prophase begins mitosis with chromosome condensation and spindle organization.
- Protein synthesis on ribosomes — Alias related to Translation: Translation is ribosomal synthesis of a polypeptide directed by mRNA codons.
- Protein-coding DNA — Alias related to Coding DNA: Coding DNA is sequence that specifies the amino-acid sequence of a protein via codons in mRNA.
- PTMs on histones — Alias related to Histone modification: Histone modifications are chemical marks on histone proteins that help regulate chromatin behavior.
- Punnett square — A Punnett square is a diagram that predicts offspring genotype probabilities from parental gametes.
R
- Recessive allele — A recessive allele determines phenotype only when two copies are present (in simple diploid Mendelian cases).
- Recessiveness — Alias related to Recessive allele: A recessive allele determines phenotype only when two copies are present (in simple diploid Mendelian cases).
- Regulation of gene expression — Alias related to Gene regulation: Gene regulation controls when, where, and how much gene products are made.
- Remodeler complex — Alias related to Chromatin-remodeling complex: Chromatin-remodeling complexes are multi-protein machines that use energy to reposition or alter nucleosomes.
- Repair of DNA — Alias related to DNA repair: DNA repair pathways detect and correct DNA damage or replication errors to protect genome integrity.
- Replication of DNA — Alias related to DNA replication: DNA replication copies the genome by using each strand as a template for a new complementary strand.
- Ribonucleic acid — Alias related to RNA: RNA (ribonucleic acid) is a nucleic acid used in gene expression, including mRNA, tRNA, rRNA, and more.
- Ribosomal RNA — Alias related to rRNA: Ribosomal RNA (rRNA) is a structural and catalytic core component of ribosomes.
- RNA — RNA (ribonucleic acid) is a nucleic acid used in gene expression, including mRNA, tRNA, rRNA, and more.
- RNA processing — RNA processing converts eukaryotic primary transcripts into mature RNAs through capping, splicing, and more.
- RNA synthesis from DNA — Alias related to Transcription: Transcription synthesizes RNA from a DNA template using RNA polymerase.
- Roles of chromatin — Alias related to Chromatin function: Chromatin functions in packaging the genome, regulating access for transcription, and supporting replication and repair.
- rRNA — Ribosomal RNA (rRNA) is a structural and catalytic core component of ribosomes.
S
- S phase — S phase is the synthesis phase when genomic DNA is replicated and sister chromatids are produced.
- Sequence mutation — Alias related to DNA mutation: A DNA mutation is a change in DNA sequence that can alter RNA and protein products or regulatory sites.
- Sequence-specific transcription factor — Alias related to Transcription factor: Transcription factors are proteins that bind specific DNA sequences to activate or repress transcription.
- Single nucleotide polymorphism — Alias related to Single-nucleotide variant: A single-nucleotide variant (SNV) is a DNA difference at one base position among individuals.
- Single-nucleotide variant — A single-nucleotide variant (SNV) is a DNA difference at one base position among individuals.
- Sister chromatids — Sister chromatids are the two identical copies of a duplicated chromosome produced by DNA replication.
- SNP — Alias related to Single-nucleotide variant: A single-nucleotide variant (SNV) is a DNA difference at one base position among individuals.
- SNV — Alias related to Single-nucleotide variant: A single-nucleotide variant (SNV) is a DNA difference at one base position among individuals.
- Splicing — Alias related to RNA processing: RNA processing converts eukaryotic primary transcripts into mature RNAs through capping, splicing, and more.
- Structure of DNA — Alias related to DNA structure: DNA structure features a sugar-phosphate backbone and complementary base pairs forming a double helix.
T
- Telomere — Telomeres are protective DNA–protein structures at the ends of linear eukaryotic chromosomes.
- Telophase — Telophase reforms nuclei around separated chromosome sets.
- TF — Alias related to Transcription factor: Transcription factors are proteins that bind specific DNA sequences to activate or repress transcription.
- Transcription — Transcription synthesizes RNA from a DNA template using RNA polymerase.
- Transcription factor — Transcription factors are proteins that bind specific DNA sequences to activate or repress transcription.
- Transcriptional enhancer — Alias related to Enhancer: An enhancer is a regulatory DNA element that increases transcription of a target gene, often from a distance.
- Transcriptional silencing — Alias related to Gene silencing: Gene silencing is the stable reduction or shutdown of gene expression by regulatory mechanisms.
- Transfer RNA — Alias related to tRNA: Transfer RNA (tRNA) delivers amino acids to the ribosome by matching anticodons to mRNA codons.
- Translation — Translation is ribosomal synthesis of a polypeptide directed by mRNA codons.
- tRNA — Transfer RNA (tRNA) delivers amino acids to the ribosome by matching anticodons to mRNA codons.
W
X
- X inactivation — Alias related to X-chromosome inactivation: X-chromosome inactivation silences most genes on one X chromosome in female mammals for dosage compensation.
- X-chromosome inactivation — X-chromosome inactivation silences most genes on one X chromosome in female mammals for dosage compensation.