# homologous

/hɑˈmɑɫəɡəs/ (US)

Source: https://englishreference.com/word/homologous
Updated: 2026-08-27

## Senses

### 2. genetics: matching chromosomes

adjective · CEFR C1 · Technical

describing a pair of chromosomes in a cell that have the same genes in the same order.

For teachers: denoting a pair of chromosomes, one inherited from each parent, that are identical in gene sequence and structure.

- During cell division, homologous chromosomes pair up before they are separated.
- The exchange of genetic material occurs between homologous chromosomes during meiosis, ensuring genetic diversity in the resulting gametes.

### 3. chemistry: series of compounds

adjective · CEFR C2 · Technical

describing a group of chemicals that have a similar structure and follow a regular pattern.

For teachers: belonging to a series of organic compounds that differ only by a repeating unit, such as a CH2 group.

- Methane and ethane are members of the same homologous series of alkanes.
- In a homologous series, physical properties like boiling points typically increase predictably as the molecular mass of the compounds grows.

### 4. mathematics: corresponding position

adjective · CEFR C2 · Technical

describing parts of different shapes or groups that are in the same relative position.

For teachers: having the same relative position, proportion, or value within different structures or geometric figures.

- The homologous sides of these two similar triangles have a ratio of two to one.
- The mapping identifies homologous points between the two topological spaces, preserving the underlying structural relationships during the transformation.

## Examples

- The wings of a bat and a bird are homologous.
- Biologists study homologous structures to understand how different species evolved from a common ancestor.
- While the specific functions of the limbs may differ, their homologous skeletal structures provide clear evidence of a shared evolutionary lineage among vertebrates.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.