GREEN HOUSE EFFECT

Infrared radiations from the Sun have short wavelength (high frequency) s they are emitted from the surface of the sun at high temperature.These radiations have more energy due to high frequency and hence they can penetrate through a glass or plastic house. But the radiations reflected or emitted from the plants in the house are of longer wavelength so they cannot penetrate through the house. So heat is retained inside the house and temperature increases.
This rise in temperate is called green house effect