photo-patch test pho·to-patch test (fō’tō-pāch’)
A test for contact photosensitization in which a patch containing the suspected sensitizer is applied to the skin for 48 hours; if there is no reaction, the area is exposed to a reddening dose of ultraviolet light; if the reaction is then positive, a more severe reaction develops at the patch site than in surrounding skin.
[foh-top-uh-thee] /foʊˈtɒp ə θi/ noun 1. movement of an organism in response to the intensity of light, especially away from the source of light. 2. any condition or disease produced by the effect of light, especially in excessive amounts.
photoperceptive pho·to·per·cep·tive (fō’tō-pər-sěp’tĭv) adj. Capable of receiving and perceiving light.
[foh-tuh-peer-ee-uh d] /ˌfoʊ təˈpɪər i əd/ noun, Biology. 1. the interval in a 24-hour during which a plant or animal is exposed to light. /ˌfəʊtəʊˈpɪərɪəd/ noun 1. the period of daylight in every 24 hours, esp in relation to its effects on plants and animals See also photoperiodism photoperiod pho·to·pe·ri·od (fō’tō-pĭr’ē-əd) n. The duration of […]
[foh-tuh-peer-ee-uh-diz-uh m] /ˌfoʊ təˈpɪər i əˌdɪz əm/ noun, Biology. 1. the response, as affecting growth or reproduction, of an organism to the length of exposure to light in a 24-hour period. /ˌfəʊtəʊˈpɪərɪəˌdɪzəm/ noun 1. the response of plants and animals by behaviour, growth, etc, to photoperiods n. 1920, from photoperiod (1920, from photo- + period) […]