Match the following: (a) Maize (i) Intercrop (b) Wheat (ii) Rabi crop (c) Trifolium (iii) Kharif crop (d) Blue-green alga (iv) Nitrogen fixing organism

(a) - (iii) Based on the seasons, the crops are categorised into Kharif crops and Rabi crops. The crops that are grown in the rainy season between June and October are called Kharif crops. A few examples of Kharif crops are maize, paddy and cotton. (b) - (ii) The crops that are grown only in winter (October to January/April) are generally called "Rabi crops". These are also known as winter season crops. Since wheat is suitable to grow in a temperate climate i.e., in a warm climate, Rabi season is the best season to cultivate it. (c) - (i) Intercropping is the process of planting a crop in between two major crops in a field such as planting Trifolium after Kharif and before Rabi. It is related to crop rotation because mostly, leguminous plants are grown in between two cereal crops to enrich the soil with nitrogenous nutrition. (d) - (iv) Air nitrogen is fixed into nitrites (compounds of nitrogen) by electrical sparks, nitrogen-fixing bacterium ( Rhizobium ) and some blue-green algae living in moist soil. The nitrogen fixed by the lightning, bacterium and blue-green algae goes into solution with water in the soil and is used as food by the plants. (a) Maize (iii) Kharif crop (b) Wheat (ii) Rabi crop (c) Trifolium (i) Intercrop (d) Blue-green alga (iv) Nitrogen fixing organism

Match the technical term with the process: Technical terms Process (a) nitrification (i) fixing air nitrogen (b) denitrification (ii) decay of dead by microbes (c) nitrogen fixation (iii) plants eaten and digested by animals (d) nitrogen assimilation (iv) nitrogen being released from decaying matter by microbes

(a) - (ii) The conversion of dead decaying matter into ammonia and then into nitrites and nitrates by nitrifying microbes is called nitrification. (b) - (iv) The conversion of nitrites and nitrates from decaying organic matter into gaseous nitrogen by denitrifying microbes is called denitrification, i.e., the release of nitrogen into the air by the action of bacteria on decaying matter. (c) - (i) The conversion of air nitrogen into nitrites and nitrates by nitrogen-fixing microorganisms is called nitrogen fixation i.e., it is the process of combining oxygen with nitrogen to form nitrogen compounds such as nitrites and nitrates. (d) - (i) In nitrogen assimilation, the atmospheric nitrogen is absorbed by Rhizobium bacteria which converts it into proteins. These bacteria are present at the roots of the plants. Here, the plant body is eaten by animals and nitrogen gets into the body of the animals. Technical terms Process (a) nitrification (ii) decay of dead by microbes (b) denitrification (iv) nitrogen being released from decaying matter by microbes (c) nitrogen fixation (i) fixing air nitrogen (d) nitrogen assimilation (iii) plants eaten and digested by animals

E M B I B E

SCIENCE For Class VIII>Chapter 1 - Crop Production and Food from Animals>EXERCISES>Q 3

MEDIUM

8th CBSE

IMPORTANT

Earn 100

Differentiate between the following:
Pesticide and weedicides.

Important Questions on Crop Production and Food from Animals

MEDIUM

8th CBSE

IMPORTANT

SCIENCE For Class VIII>Chapter 1 - Crop Production and Food from Animals>EXERCISES>Q 4

Differentiate between the following:
Mixed farming and mixed cropping.

HARD

8th CBSE

IMPORTANT

SCIENCE For Class VIII>Chapter 1 - Crop Production and Food from Animals>EXERCISES>Q 5

Differentiate between the following:
Nitrification and denitrification.

MEDIUM

8th CBSE

IMPORTANT

SCIENCE For Class VIII>Chapter 1 - Crop Production and Food from Animals>EXERCISES>Q 6

Differentiate between the following:
Plantation and a cereal crop.

EASY

8th CBSE

IMPORTANT

SCIENCE For Class VIII>Chapter 1 - Crop Production and Food from Animals>EXERCISES>III

Match the following:

(a) Maize	(i) Intercrop
(b) Wheat	(ii) Rabi crop
(c) Trifolium	(iii) Kharif crop
(d) Blue-green alga	(iv) Nitrogen fixing organism

MEDIUM

8th CBSE

IMPORTANT

SCIENCE For Class VIII>Chapter 1 - Crop Production and Food from Animals>EXERCISES>Q IV

Match the technical term with the process:

Technical terms	Process
(a) nitrification	(i) fixing air nitrogen
(b) denitrification	(ii) decay of dead by microbes
(c) nitrogen fixation	(iii) plants eaten and digested by animals
(d) nitrogen assimilation	(iv) nitrogen being released from decaying matter by microbes