Photoperiodism, Biology

Assignment Help:

Photoperiodism

Activity like breeding and migration in animals; flowering, seed germination in plants are regulated by the length of daily period of light and darkness. This behavioural phenomenon is known as photoperiodism. For example, plants such as radish, potatoes and spinach bloom when the light duration is more than 12 hours/day. Such plants are called long day plants. Cereal, tobacco, dahelia and many other plants bloom when light duration is less than 12 hrs/day. These are called short day plants. Such responses show that plants have built-in mechanisms for measuring the duration of illumination and darkness and hence flower in a specific seasons.

Similar photoperiodic responses are observed in animals. These may be diurnal, lunar or annual. Reproduction and migration in birds are such annual photoperiodic responses. From such responses it seems that distribution of some plants and animals may be restricted because the necessary photoperiodic stimulus is available only at certain latitudes.


Related Discussions:- Photoperiodism

How are fishes characterized, Q. Fish identity card. How are fishes charact...

Q. Fish identity card. How are fishes characterized according to examples of representing beings, skin, basic morphology, circulation, nitrogen waste, respiration, thermal control

Skeletal system - ribs, RIBS- Curved or stretched 'S' sha...

RIBS- Curved or stretched 'S' shaped bones. 12 pairs, form thoracic basket, attached by head part to vertebral column and by tail part to sternum. 7 pairs a

Preformation theory - pre-mendelian theory, Preformatio n Theory (1632-172...

Preformatio n Theory (1632-1723) (i)         Scientist 'Malpighi Swammerdam' propounded the preformation theory. This theory holds that the sex cells (sperm and ova) had the m

How can bacteria produce human insulin, Q. How can bacteria produce human i...

Q. How can bacteria produce human insulin on an industrial scale? What are the other forms of insulin made available by the pharmaceutical industry? Bacteria don't naturally sy

Phylum cnidaria (coelenterata ), PHYLUM  CNIDARIA (= COELENTERATA )       ...

PHYLUM  CNIDARIA (= COELENTERATA )         Definition and Introduction Tissue  grade eumetazoans with  a radial  symmetry .The  term  coelenterate  signifies the  presence

Explain what is fungi, Explain what is Fungi? The fungi are spore-beari...

Explain what is Fungi? The fungi are spore-bearing eukaryotic organisms without chlorophyll and having absorptive nutrition. These reproduce sexually as well asexually. Primari

Define instrument for measurement of absorbed radiation, Define Instrument ...

Define Instrument for Measurement of Absorbed Radiation? a) Photometer: This is an instrument which it designed to measure the intensity of the beam of light and usually does s

Excretion, State the excretory organelles of various organisms

State the excretory organelles of various organisms

The best describes the acid properties of guanine, Which statement best des...

Which statement best describes the acid/base properties of guanine? -at pH, guanine will be negatively charge -at pH, guanine will be neutral -it will be an effective buff

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd