Chromosomes

Chromosome

A unique DNA molecule in a cell

Gene

A specific DNA segment that codes for a protein or functional RNA

Prokaryote

An organism with a single, circular chromosome

Eukaryote

An organism with multiple, linear chromosomes

Genome

The total genetic material of an organism

Genome Size

The total amount of DNA in an organism's genome

Gene Number

The total number of genes in an organism's genome

Euchromatin

The less condensed and transcriptionally active region of a eukaryotic chromosome

Heterochromatin

The highly condensed and transcriptionally inactive region of a eukaryotic chromosome

Centromere

The region of a chromosome that holds the two sister chromatids together

Telomere

The protective cap at the ends of chromosomes

Nucleosome

The basic structural unit of chromatin, consisting of DNA wrapped around histone proteins

Histone Proteins

Proteins that help package DNA into nucleosomes

Chromatin

The complex of DNA and proteins that make up chromosomes

Chromosome Compaction

The process of condensing and organizing chromosomes in the nucleus

Polyploidy

The condition of having more than two complete sets of chromosomes

Aneuploidy

The condition of having an abnormal number of chromosomes

Karyotype

The arrangement of chromosomes pairs by length

Autopolyploid

A polyploid with all chromosomes derived from a single ancestral species

Allopolyploid

A polyploid with complete sets of chromosomes from two or more different ancestral species

Monosomy

The condition of missing one copy of a chromosome

Trisomy

The condition of having one extra copy of a chromosome

Euploid

Having an equal number of each chromosome

Diploid

Having two copies of each chromosome

Haploid

Having one copy of each chromosome

Sex Chromosome

A chromosome involved in determining the sex of an organism

X Inactivation

The process in female mammals where one X chromosome is inactivated to achieve dosage compensation

Barr Body

The inactivated X chromosome in female mammals