DIRECTIONS for Q. 35: Given question contain STATEMENT-1 (Assertion) and STATEMENT-2 (Reason) and has 4 choices (a), (b), (c) and (d) out of which ONLY ONE is correct.

Statement 1:Netprimary productivity is gross primary productivity minus respiration.
Statement 2: Secondary productivity is produced by heterotrophs

Statement- 1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement -1
Statement -1 is True, Statement -2 is True ; Statement-2 is NOT a correct explanation for Statement - 1
Statement - 1 is True, Statement- 2 is False
Both the Statements are False

Solution

Net primary productivity is the rate of organic matter built up or stored by producers in their bodies per unit time and area. Net productivity is equal to gross primary productivity minus loss due to respiration and other reasons. Rate of increase in energy containing organic matter or biomass by heterotrophs or consumers per unit time and area is known as secondary productivity.

Which of the following include (s) ecosystem services ?
1.Purification of air and water by forests
2.Forests mitigate droughts and flood
3.Forests act as storehouse of carbon
4.Forests influence hydrological cycle

1 and 3
1 and 4
1, 2 and 3
All of these

Solution

Healthy ecosytems provide a wide range of economic,environmental and aesthetic goods and services.Ecosystem services refer to the product of ecosystem processes. Forests maintain biodiversity and generate fertile soils.

Food chains differ from food webs in that
1.food chains are single sequence of who eats whom in a community.
2.food chains better represent the entire community.
3.food webs represent the complex interaction among food chains.
4.food chain is the flow of energy in a population.

1 and 3
1 and 4
1, 2 and 3
1, 2, 3 and 4

Match column – I with column -II and choose the correct option.

A→(c); B→(b); C→(d); D→(a)
A→(c); B→(a); C→(d); D→(b)
A→(a); B→(c); C→(b); D→(d)
A→(b); B→(c); C→(d); D→(a)

Find out the pairs which are correctly matched.

A→(c); B→(b); C→(d); D→(a)
A→(c); B→(a); C→(d); D→(b)
A→(a); B→(c); C→(b); D→(d)
A→(b); B→(c); C→(d); D→(a)

Which of the following statements is not a major concern about our altering of the carbon cycle?

The Greenland and Antarctic ice caps are expected to melt if global warming continues.
High-sulphur fuels are used by power plants because they are less expensive than low-sulphur fuels.
The increase in atmospheric CO₂ exceeds the ability of the oceans to absorb the increase.
CO₂ is a gas that traps infrared radiation

Solution

The use of high-sulphur coal has more to do with acid precipitation than it does with global warming.

Which ecosystem does not show variations dependent upon geographic location and rainfall?

Marine ecosystem
Fresh water ecosystem
Desert ecosystem
Tropical ecosystem

Which of the following in an ecosystem exhibits one way flow rather than cyclic flow ?

Potassium
Carbon
Free energy
Nitrogen

Phosphorus usually becomes a limiting factor at certain times of the year in

Aquatic ecosystem
Grassland ecosystem
Forest ecosystem
All of the above

Find out the correct order of succession levels in Xerarch

Lichen moss stage, Annual herb stage, Perennial herb stage, Scrub stage, Forest
Annual herb stage, Perennial herb stage, Lichen moss stage, Scrub stage, Forest
Perennial herb stage, Annual herb stage, Perennial Scrub stage, Lichen moss stage, Forest
Scrub stage, Forest, Annual herb stage, Lichen moss stage, Scrub stage, Forest

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