Chromosomes and Cell Division Vocabulary

A set of vocabulary flashcards summarising key genetic terms related to chromosomes, cell types, and cell division.

Locus

The specific physical location of a gene on a chromosome.

Linked genes

Genes located on the same chromosome and therefore often inherited together.

Chromosomes

Thread-like structures of condensed DNA found in the nucleus that carry genetic information.

Centromere

The chromosome region that joins sister chromatids and anchors the kinetochore during cell division.

Telomere

Protective DNA cap at each chromosome tip that prevents loss of important genetic information during replication.

Kinetochore

Protein complex at the centromere that attaches chromosomes to the spindle during cell division.

Chromatid

One of the two identical DNA strands of a replicated chromosome.

Sister chromatids

The pair of identical chromatids formed after DNA replication and joined at the centromere.

Autosomes

The 22 pairs of non-sex chromosomes that are the same in males and females.

Sex chromosomes

Chromosomes (X and Y in humans) that determine biological sex.

X chromosome

One type of human sex chromosome; females have two (XX), males have one (XY).

Y chromosome

The smaller human sex chromosome that pairs with X in males (XY).

Somatic cells

All body cells other than gametes; contain 46 chromosomes in humans.

Homologous chromosomes

A matching pair of chromosomes that have the same size, centromere position, and gene banding patterns.

Non-homologous chromosomes

Chromosomes that do not match in size, centromere position, or banding pattern (e.g., chromosome 21 vs. chromosome 11).

Karyotype

An ordered image of an individual’s chromosomes arranged in homologous pairs from largest to smallest.

Trisomy

Chromosomal condition in which three copies of a particular chromosome are present instead of two.

Monosomy

Chromosomal condition in which only one copy of a particular chromosome is present instead of two.

Gametes

Reproductive cells (sperm or ova) containing half the usual number of chromosomes.

Mitosis

Cell division that produces two genetically identical somatic cells with the same chromosome number as the original cell.

Meiosis

Cell division that produces gametes with half the original chromosome number, generating genetic variation.

Ova (Ovum)

Female gametes (egg cells) containing 23 chromosomes in humans.

Sperm

Male gametes containing 23 chromosomes in humans.

Haploid

Having one copy of each chromosome (n); characteristic of gametes.

Fertilisation

Fusion of a sperm and an ovum to form a zygote.

Zygote

The first cell of a new organism formed by fertilisation; contains 46 chromosomes in humans.