homologous

adjective

ho·​mol·​o·​gous hō-ˈmä-lə-gəs 

hə-

1

a

: having the same relative position, value, or structure: such as

(1)

biology : exhibiting biological homology

(2)

biology : having the same or allelic genes with genetic loci usually arranged in the same order

homologous chromosomes

b

chemistry : belonging to or consisting of a chemical series (see series sense 6) whose successive members have a regular difference in composition especially of one methylene group

2

biology : derived from or developed in response to organisms of the same species

a homologous tissue graft

Did you know?

In his famous discussion of the panda's thumb, Stephen Jay Gould carefully explains how this thumb is not homologous to the human thumb. Although the two digits are used in much the same way (the panda's thumb is essential for stripping bamboo of its tasty leaves, the staple of the panda's diet), the panda's thumb developed from a bone in its wrist and is an addition to the five "fingers" of its paw. The tiny stirrup and anvil bones of our inner ear, however, do seem to be homologous with the bones that allow a garter snake to swallow a frog whole.

Examples of homologous in a Sentence

Recent Examples on the Web

Brain probes conducted during virtual jaunts have uncovered many points that apply to the human brain also, which is homologous to the mouse brain, Dombeck notes. —IEEE Spectrum, 9 Dec. 2023

While the similarity could be just phenomenological, this indicates a possibility that mycelium networks transform information via interaction of spikes and trains of spikes in manner homologous to neurons. —Lloyd Alter, Treehugger, 20 Oct. 2023

For example, people with prostate or ovarian cancers can use biomarker testing to see if their cancer has homologous recombination repair (HRR) mutations, and people with ovarian cancer can use this type of testing to determine if their cancer has homologous recombination deficiency (HRD). —Alice Oglethorpe, Country Living, 2 Mar. 2021

These include cutting the genome into fragments that can later be joined together or, more recently, using the ISA protocol, whereby overlapping fragments naturally come together in cells through homologous recombination: a phenomenon in which two DNA molecules exchange fragments. —Virginie Courtier, Quartz, 4 June 2021

That means that the offspring are going to have two homologous chromosomes which are reflective of very different ancestral histories. —Razib Khan, Discover Magazine, 9 July 2011

No homologous primate facial expression is known; however, some facial expressions displayed by high-status animal aggressors involve smile components. —Neuroskeptic, Discover Magazine, 28 July 2017

Again, homologous boosting is when the booster is the same vaccine type as the primary series. —Bruce Y. Lee, Forbes, 10 Oct. 2022

In general, these have shown it’s about as good as, and in some cases better than, a homologous regimen. —Rachel Gutman, The Atlantic, 14 Oct. 2021

Word History

Etymology

Greek homologos agreeing, from hom- + legein to say — more at legend

First Known Use

1660, in the meaning defined at sense 1a

Kids Definition

homologous

adjective

ho·​mol·​o·​gous hō-ˈmäl-ə-gəs 

hə-

1

: showing biological homology

a homologous wing and arm

2

: having the same or allelic genes usually arranged in the same order

a pair of homologous chromosomes

Medical Definition

homologous

adjective

ho·​mol·​o·​gous hō-ˈmäl-ə-gəs, hə- 

1

a

: having the same relative position, value, or structure: as

(1)

: exhibiting biological homology

(2)

: having the same or allelic genes with genetic loci usually arranged in the same order

homologous chromosomes

b

: belonging to or consisting of a chemical series whose members exhibit homology

2

a

: derived from or involving organisms of the same species

homologous tissue grafts

compare autologous, heterologous sense 1

b

: relating to or being immunity or a serum produced by or containing a specific antibody corresponding to a specific antigen

homologously

-lē 

adverb