photoperiod

[ foh-tuh-peer-ee-uhd ]

noun

, Biology.

1. the interval in a 24-hour period during which a plant or animal is exposed to light.

photoperiod

/ ˌfəʊtəʊˈpɪərɪəd /

noun

1. See photoperiodism
   the period of daylight in every 24 hours, esp in relation to its effects on plants and animals See also photoperiodism

photoperiod

/ fō′tō-pîr′ē-əd /

1. The duration of an organism's daily exposure to light, considered especially with regard to the phenomena of photoperiodism.

Derived Forms

• ˌphotoˌperiˈodically, adverb
• ˌphotoˌperiˈodic, adjective

Other Words From

• pho·to·pe·ri·od·ic [foh-t, uh, -peer-ee-, od, -ik], photo·peri·odi·cal adjective
• photo·peri·odi·cal·ly adverb

Word History and Origins

Origin of photoperiod¹

First recorded in 1915–20; photo- + period

Example Sentences

Broad limits to functional reproductive activity seem to be set by the photoperiod—neuroendocrine system.

From Project Gutenberg

These captives had been kept for several months at a temperature of 21 degrees Centigrade, and on a daily photoperiod of 15 hours.

From Project Gutenberg

The mice were kept in a room in which temperature and photoperiod were controlled.

From Project Gutenberg

In general, Tb's showed a marked circadian cycle in phase with photoperiod.

From Project Gutenberg