homologous

[ huh-mol-uh-guhs, hoh- ]

adjective

1. having the same or a similar relation; corresponding, as in relative position or structure.
2. corresponding in structure and in origin, but not necessarily in function:

   The wing of a bird and the foreleg of a horse are homologous.

3. having the same alleles or genes in the same order of arrangement:

   homologous chromosomes.

4. Chemistry. of the same chemical type, but differing by a fixed increment of an atom or a constant group of atoms:

   Methyl and ethyl alcohols are homologous.

5. Immunology. pertaining to an antigen and its specific antibody.

homologous

/ ˌhɒm-; həʊˈmɒləɡəs; hɒ-; ˌhəʊməˈlɒdʒɪkəl /

adjective

1. having a related or similar position, structure, etc
2. chem (of a series of organic compounds) having similar characteristics and structure but differing by a number of CH 2 groups
3. med
   1. (of two or more tissues) identical in structure
   2. (of a vaccine) prepared from the infecting microorganism
4. biology (of organs and parts) having the same evolutionary origin but different functions Compare analogous

   the wing of a bat and the paddle of a whale are homologous

5. maths (of elements) playing a similar role in distinct figures or functions

homologous

/ hə-mŏl′ə-gəs /

1. Similar in structure and evolutionary origin but having different functions, as a human's arm and a seal's flipper.
2. Being one of a pair of chromosomes, one from the female parent and one from the male parent, that have genes for the same traits in the same positions. Genes on homologous chromosomes may not have the same form, however. For example, one chromosome in a pair of homologous chromosomes may contain a gene for brown eyes, and the other a gene for blue eyes. Human females have 23 pairs of homologous chromosomes (including the two X chromosomes), while human males have 22 because the Y chromosome is not paired.
3. Belonging to or being a series of organic compounds, each successive member of which differs from the preceding member by a constant increment, especially by an added CH 2 group. The alkanes (methane, ethane, propane, and others) are a homologous series of compounds.
4. Involving organisms of the same species, as in grafted body tissues.

Derived Forms

• ˌhomoˈlogically, adverb

Other Words From

• nonho·molo·gous adjective
• unho·molo·gous adjective

Word History and Origins

Origin of homologous¹

1650–60; < Medieval Latin homologus < Greek homólogos agreeing, equivalent to homo- homo- + -logos proportional, equivalent to log- (stem of lógos proportion; logos ) + -os -ous

Example Sentences

The main novelty of this discovery is that the new compound, alongside the previous one, forms what's known as a 'homologous series.'

From Science Daily

Worth noting, this work presents the first homologous series based on defect ordering found for hybrid organic-inorganic perovskites.

From Science Daily

Typically, most animal and plant species exhibit a minimum of one and a maximum of three crossovers per a pair of homologous chromosomes.

From Science Daily

Tumor molecular characteristics were analyzed before treatment, and patients were categorized into biomarker-matched or -unmatched treatment cohorts based on ATM alterations, homologous recombination repair defects, STK11/LKB1 alterations, or high CD73 expression.

From Science Daily

Chromosomes come in pairs called homologous chromosomes that carry the genes we inherited from each of our parents -- one from our mom, one from our dad.

From Science Daily