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photoperiodism
4 dictionary results for: Photoperiodism
Dictionary.com Unabridged (v 1.1) - Cite This Source - Share This
pho·to·pe·ri·od·ism 
[foh-tuh-peer-ee-uh-diz-uhm] Pronunciation Key
[foh-tuh-peer-ee-uh-diz-uhm] Pronunciation Key –noun Biology.
| the response, as affecting growth or reproduction, of an organism to the length of exposure to light in a 24-hour period. |
Dictionary.com Unabridged (v 1.1)
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.
American Heritage Dictionary - Cite This Source - Share This
| pho·to·pe·ri·od·ism
(fō'tō-pîr'ē-ə-dĭz'əm) Pronunciation Key
n. pl. pho·to·pe·ri·od·isms also pho·to·pe·ri·o·dic·i·ties The response of an organism to changes in its photoperiod, especially as indicated by vital processes. |
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The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2006 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2006 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
The American Heritage Science Dictionary - Cite This Source - Share This
| photoperiodism (fō'tō-pîr'ē-ə-dĭz'əm) also photoperiodicity
(fō'tō-pîr'ē-ə-dĭz'əm) Pronunciation Key
The response of an organism to changes in its photoperiod, especially as indicated by vital processes. For example, many plants exhibit photoperiodism by flowering only after being exposed to a set amount of daylight, as by requiring either a long or short day to flower. Plant growth, seed germination, and fruiting are also affected by day length. Photoperiodic responses in plants are regulated by special pigments known as phytochromes. In animals, migration, mating, amount of sleep, and other behaviors are also photoperiodic. In many animals, photoperiodism is regulated by the hormone melatonin. |
The American Heritage® Science Dictionary
Copyright © 2002 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Copyright © 2002 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
American Heritage Stedman's Medical Dictionary - Cite This Source - Share This
photoperiodism pho·to·pe·ri·od·ism (fō'tō-pĭr'ē-ə-dĭz'əm) or pho·to·pe·ri·o·dic·i·ty (-pĭr'ē-ə-dĭs'ĭ-tē)
n.
The response of an organism to changes in its photoperiod, especially as indicated by vital processes.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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