Ecosystem Questions — NEET Biology

Q1

Secondary Succession takes place on/in :

A Degraded forest

B Newly created pond

C Newly cooled lava

D Bare rock

Correct Answer

Option A

Solution

(a) Secondary succession takes place in disturbed areas having poor vegetation.

Q2

Mass of living matter at a trophic level in an area at any time is called

A standing crop

B detritus

C humus

D standing state

Correct Answer

Option A

Solution

(a) Standing crop: total mass/quantity of organisms at a trophic level at a given time.

Q3

Pyramid of numbers in a grassland ecosystem is

A always inverted

B always upright

C both A and B

D spindle-shaped

Correct Answer

Option B

Solution

(b) In grassland, numbers decrease at each successive trophic level → upright pyramid.

Q4

Greatest producers of organic matter are

A crop plants

B forests

C plants of the land area

D phytoplankton of oceans

Correct Answer

Option D

Solution

(d) Phytoplanktons (algae) of oceans are the highest producers of organic matter.

Q5

Upper part of sea/aquatic ecosystem contains

A plankton

B nekton

C plankton and nekton

D benthos

Correct Answer

Option A

Solution

(a) Plankton passively float in upper water. Nekton actively swim. Benthos lead sedentary life on sea bottom.

Q6

In an ecosystem, which one shows one-way passage

A free energy

B carbon

C nitrogen

D potassium

Correct Answer

Option A

Solution

(a) Energy flows unidirectionally (one-way); nutrients (C, N, P) cycle.

Q7

Pneumatophores are characteristic of plants growing in

A saline soils

B sandy soils

C marshy places and salt lakes

D dryland regions

Correct Answer

Option C

Solution

(c) Plants in salty marshes develop special roots for respiration called pneumatophores.

Q8

In relation to Gross primary productivity and Net primary productivity of an ecosystem, which statement is correct?

A Gross primary productivity is always more than net primary productivity

B Gross primary productivity and Net primary productivity are one and same

C There is no relationship between Gross primary productivity and Net primary productivity

D Gross primary productivity is always less than net primary productivity

Correct Answer

Option A

Solution

(a) Net primary productivity = GPP - respiration. Hence, GPP is always more than NPP.

Q9

Natural reservoir of phosphorus is

A Animal bones

B Rock

C Fossils

D Sea water

Correct Answer

Option B

Solution

(b) Phosphorus reservoir: phosphate rocks (sedimentary cycle).

Q10

Increase in concentration of the toxicant at successive trophic levels is known as :

A Biodeterioration

B Biotransformation

C Biogeochemical

D Biomagnification

Correct Answer

Option D

Solution

(d) Biomagnification means increase in concentration of toxins through the trophic levels of a food chain.