Fungi give support to the algae, give protection and help in absorption of water while algae provide food to fungi which is achlorophyllous.
No one is harmed but both are benefitted by each other.11.
The regulation of water resources to prevent flood will help not only in soil conservation but also supply an adequate water supply in the period of drought.10.
The relation between algae and fungi in lichen is (a) symbiosis(b) parasitism(c) commenalism(d) protocooperation. (a): Algae and fungi in a lichen show symbiotic relationship.
Soil conservation is (a) conversion of sterile soil into fertile one(b) aeration of soil(c) erosion of soil(d) protection against loss. (d): Soil conservation is to conserve fertile soil from the losses like heavy rainfall, drainage, high wind, flood, draught etc.
Soil is the top cover of the earth in which plants can grow.
Green house effect is warming due to (a) infra-red rays reaching earth(b) moisture layer in atmosphere(c) increase in temperature due to increase in carbon dioxide concentration of atmosphere(d) ozone layer of atmosphere. (c): The mean global temperature rise by 2° – 6°c and the concentration of carbon dioxide increases in the troposphere upto 600 ppm.
Hence, the surface of the earth becomes warm which causes global warming.
Major aerosol pollutant in jet plane emission is (a) sulphur dioxide(b) carbon monoxide(c) methane(d) fluorocarbon. (d): Aerosols are chlorofluoro-hydrocarbon compounds released into air with force in the form of vapour.
Main source of aerosols is the emission of jet planes, where fluorocarbons are used.