Match the following columns (I) and (II): Column I Column II (a) Conversion of nitrogen to ammonia (i) CFCs (b) Number of elements of oxygen in one molecule (ii) Nitrosomonas (c) Conversion of complex organic compounds (proteins) into ammonia (iii) 150% (d) Nitrite to Nitrate (iv)Nitrobacter (e) Formation of N2 from nitrates and nitrites (v) Nitrogen fixation (f) Ozone layer depletion (vi) CO2 (g) Ammonia to Nitrite (vii) 40 km (h) Percentage of humus in normal soil (viii) Denitrification (i) Gas that constitute the maximum percentage of greenhouse gases (ix) 2 (j)Thickness of ozone layer is about (x) 120 km (xi) Ammonification (xii) 3

(a) — (v) Several bacteria such as Rhizobium etc. are involved in the process of fixation of nitrogen to the soil and make it available for the plants. (b) — (ix) Oxygen is a diatomic molecule which is used by humans for inhalation and is released by plants as a by-product of photosynthesis. In the atmosphere, it is found as a gas. (c) — (xi) The proteins are broken down by the plants and are converted to ammonia . (d) — (iv) Conversion of nitrite to nitrate is a step in the process of nitrogen fixation which is done by the bacteria Nitrobacter and that process is called nitrification . (e) — (viii) Pseudomonas is involved in the denitrification process. This process is important to maintain the nitrogen percentage of the atmosphere. These bacteria can perform under anaerobic condition. (f) — (i) Ozone is present in the stratosphere. The ozone layer is depleting by the CFC gas. This gas is emitted by the refrigerator, air conditioners, etc. (g) — (ii) Conversion of ammonia to nitrite is an important step in the process of nitrogen fixation. This is an aerobic process. This process is done by a group of bacteria that belongs to a genus Nitrosomonas. (h) — (iii) The amount of humus determines the fertility of the soil. Humus is an inorganic material. Manures, but not fertilizers, add humus in the soil. It helps in holding of water in the soil. (i) — (vi) The greenhouse gases help to entrap the heat of the environment and maintain a sustainable temperature. These gases result in the greenhouse effect. (j) — (vii) The ozone layer helps to protect the Earth from the harmful UV rays. This layer is about 40km thick. Column I Column II (a) Conversion of nitrogen to ammonia (v) Nitrogen fixation (b) Number of elements of oxygen in one molecule (ix) 2 (c) Conversion of complex organic compounds (proteins) into ammonia (xi) Ammonification (d) Nitrite to Nitrate (iv)Nitrobacter (e) Formation of N2 from nitrates and nitrites (viii) Denitrification (f) Ozone layer depletion (i) CFCs (g) Ammonia to Nitrite (ii) Nitrosomonas (h) Percentage of humus in normal soil (iii) 150% (i) Gas that constitute the maximum percentage of greenhouse gases (vi) CO2 (j)Thickness of ozone layer is about (vii) 40 km

E M B I B E

Secondary Biology FIrst And Second Term of CLASS IX>Chapter 5 - Natural Resources>Diagrammatic Questions>Q 3

MEDIUM

9th CBSE

IMPORTANT

Earn 100

Draw a neat and well-labelled diagram of the nitrogen cycle.

Important Questions on Natural Resources

MEDIUM

9th CBSE

IMPORTANT

Secondary Biology FIrst And Second Term of CLASS IX>Chapter 5 - Natural Resources>Match The Following>Q 1

Match the following columns (I) and (II):

Column I	Column II
(a) Conversion of nitrogen to ammonia	(i) CFCs
(b) Number of elements of oxygen in one molecule	(ii) Nitrosomonas
(c) Conversion of complex organic compounds (proteins) into ammonia	(iii) 150%
(d) Nitrite to Nitrate	(iv)Nitrobacter
(e) Formation of N2 from nitrates and nitrites	(v) Nitrogen fixation
(f) Ozone layer depletion	(vi) CO2
(g) Ammonia to Nitrite	(vii) 40 km
(h) Percentage of humus in normal soil	(viii) Denitrification
(i) Gas that constitute the maximum percentage of greenhouse gases	(ix) 2
(j)Thickness of ozone layer is about	(x) 120 km
	(xi) Ammonification
	(xii) 3