Meaning & use
homologous chromosome
Last updated
Meaning
nouncountablebiology
Either member of a matched pair of chromosomes that carry the same genes in the same order, with one copy coming from each parent.
Grammar: Usually plural or paired: a cell holds two homologous chromosomes of each type.
Patterns
- a pair of homologous chromosomes
- homologous chromosomes separate
- crossing over between homologous chromosomes
Chromosome 7 from your mother and chromosome 7 from your father are homologous chromosomes.
During meiosis, each homologous chromosome lines up beside its partner before the two are pulled apart.
The two homologous chromosomes may carry different versions of the same gene.
Word forms
| plural | homologous chromosomes |
|---|
Common combinations
- pair of homologous chromosomes
- Humans have 23 pairs of homologous chromosomes in most body cells.
- homologous chromosomes pair up
- Early in meiosis, homologous chromosomes pair up along their whole length.
- separation of homologous chromosomes
- The separation of homologous chromosomes gives each egg or sperm cell half the usual set.
- crossing over between homologous chromosomes
- Crossing over between homologous chromosomes shuffles the genes passed to offspring.
- maternal and paternal homologous chromosomes
- Each cell contains maternal and paternal homologous chromosomes that match gene for gene.
Synonyms and how they differ
- homolog
- Homolog is a shorter, mostly spoken or lab-setting form, and it can also refer to similar genes or structures, not only whole chromosomes.
- homologue
- Homologue is the British spelling of homolog and carries the same broad scientific meaning.
- chromosome pair
- Chromosome pair is a looser everyday phrase that does not stress that the two partners match in gene content.
Opposites
Word family
- homology noun
- similarity of structure or origin between parts of different organisms or molecules
- homologous adjective
- having matching structure or origin
- chromosome noun
- a threadlike structure in a cell that carries genes
- chromosomal adjective
- relating to chromosomes
Commonly confused: homologous chromosome or sister chromatid?
homologous chromosome vs sister chromatid
Sister chromatids are two identical copies of one chromosome joined together, whereas homologous chromosomes are two separate chromosomes, one from each parent, that are similar but not identical.
Practice
Which statement correctly describes a pair of homologous chromosomes?
Choose one answer.
Homologous chromosomes come one from each parent and match in gene order, though their gene versions may differ. The first option describes sister chromatids, which are identical copies.
Make it your own
Write a sentence using “homologous chromosome”, then check it and compare it with the examples above.