Ecosystem — Page 4 | NEET Biology

Q31

Which of the following is expected to have the highest value (gm/m2/yr) in a grassland ecosystem?

A Secondary Production

B Tertiary Production

C Gross Production (GP)

D Net Production (NP)

Correct Answer

Option C

Solution

(c) Gross production will have the highest value as Net production subtracts respiratory utilization.

Q32

Which one of the following ecosystem types has the highest annual net primary productivity?

A tropical deciduous forest

B temperate evergreen forest

C temperate deciduous forest

D tropical rain forest.

Correct Answer

Option D

Solution

(d) Tropical rain forests have the highest net primary productivity.

Q33

The slow rate of decomposition of fallen logs is due to their

A low moisture content

B poor nitrogen content

C anaerobic environment around them

D low cellulose content

Correct Answer

Option A

Solution

(a) Low moisture content decreases number of decomposers because decomposers need optimum moisture.

Q34

About 70% of total global carbon is found in

A grasslands

B agroecosystems

C oceans

D forests

Correct Answer

Option C

Solution

(c) About 70% of total global carbon is found in oceans which regulates atmospheric CO2.

Q35

Of the total incident solar radiation the proportion of PAR is :

A about 70%

B about 60%

C less than 50%

D more than 80%

Correct Answer

Option C

Solution

(c) About 50% of total incident solar radiation forms Photosynthetically Active Radiation (PAR).

Q36

The breakdown of detritus into smaller particles by earthworm is a process called

A humification

B fragmentation

C mineralisation

D catabolism

Correct Answer

Option B

Solution

(b) The breakdown of detritus into smaller particles by earthworm is known as fragmentation.

Q37

The rate of formation of new organic matter by rabbit in a grassland, is called

A net productivity

B secondary productivity

C net primary productivity

D gross primary productivity

Correct Answer

Option B

Solution

(b) At the trophic level of consumers, the rate at which food energy is assimilated is called secondary productivity.

Q38

Match the following and select the correct option about ecosystem services, detrivores, pioneer species, natality

A & (i) & (ii) & (iii) & (iv) \

B & (iv) & (i) & (iii) & (ii) \

C & (iii) & (ii) & (iv) & (i) \

D & (ii) & (i) & (iv) & (iii) array

Correct Answer

Option D

Solution

(d) Detrivores break down detritus into smaller particles.

Pioneer species invade bare areas.

Ecosystem services are products of ecosystem processes.

Natality refers to births.

Q39

Which of the following pairs is a sedimentary type of biogeochemical cycle?

A oxygen and nitrogen

B phosphorus and sulphur

C phosphorus and nitrogen

D phosphorus and carbon dioxide

Correct Answer

Option B

Solution

(b) Phosphorus and sulphur cycles are sedimentary (non-gaseous reservoir).

Q40

The main role of bacteria in the carbon cycle involves

A photosynthesis

B chemosynthesis

C digestion or breakdown of organic compounds

D assimilation of nitrogenous compounds

Correct Answer

Option C

Solution

(c) Bacteria decompose organic compounds → release CO2 back into atmosphere.