Homologní

Homologní is a Czech adjective used in biology and chemistry to describe relationships arising from a common origin or from a regular, repeating pattern in a series of related forms. In biology, it is applied to homologní chromozomy, homologní struktury and homologní geny; in chemistry, to homologní řada or homologní sloučeniny, where members differ by a repeating unit such as CH2.

In genetics, homologní chromozomy are chromosome pairs in diploid organisms that carry the same genes at the same loci, one inherited from each parent. They pair during meiosis and may exchange genetic material through crossing over. Homologní struktury are anatomical features that originate from the same embryonic structure, such as the forelimbs of humans, bats and whales, which have similar bone plans but different functions.

Homologní geny are genes descended from a single ancestral gene; this category includes orthologs across species and paralogs within a genome, reflecting divergent evolutionary paths.

In chemistry, a homologní řada comprises compounds with a common functional group and a repeating unit, most often a CH2 group, so that properties change gradually with increasing chain length. The term contrasts with analogous similarities (analogies) that arise without a shared ancestry.