Does light factor affect distribution of organisms? Write a brief note giving suitable examples of eir plants or animals. 

Light is an important factor in determining the distribution of organisms. We know that green plants need sunlight to carry out photosynthesis and hence distribution of green plants is highly dependent on the amount of illumination. This is the reason, tropics are having dense plant cover but poles have negligible plants. Moreover, plants also need sunlight for flowering. This phenomenon is called photoperiodism. Hence, on the basis of photoperiodism plants are categorised as short day plants, long day plants and day neutral plants. The area near equator get long duration of light as compared to area near poles. Thus. this affect distribution of plants on earth.
Animals too depend on light and show certain behavioural pattern on the basis of diurnal and seasonal variations in light. Many animals get up early in the morning and start foraging. The nocturnal animals remain active during night only. e.g. owl. Reproductive and migratory activities are also governed by the amount and period of illumination in many animals.