Ecosystem — Page 2 | NEET Biology

Q11

The second stage of hydrosere is occupied by plants like

A Azolla

B Typha

C Salix

D Vallisneria

Correct Answer

Option D

Solution

(d) In hydrosere: phytoplankton stage → submerged plant stage (Vallisneria, Hydrilla) → floating plant stage...

Q12

During ecological succession:

A the establishment of a new biotic community is very fast in its primary phase.

B the numbers and types of animals remain constant.

C the changes lead to a community that is in near equilibrium with the environment called pioneer community.

D the gradual and predictable change in species composition occurs in a given area.

Correct Answer

Option D

Solution

(d) Ecological succession involves gradual and predictable changes in species composition in a given area.

Q13

Which ecosystem has the maximum biomass?

A Grassland ecosystem

B Pond ecosystem

C Lake ecosystem

D Forest ecosystem

Correct Answer

Option D

Solution

(d) Forest ecosystem has the maximum biomass.

Q14

What type of ecological pyramid would be obtained with: Secondary consumer 120g, Primary consumer 60g, Primary producer 10g?

A Inverted pyramid of biomass

B Pyramid of energy

C Upright pyramid of biomass

D Upright pyramid of numbers

Correct Answer

Option A

Solution

(a) The given data shows an inverted pyramid of biomass (producers less than consumers).

Q15

Which of the following ecological pyramids is generally inverted?

A Pyramid of numbers in grassland

B Pyramid of energy

C Pyramid of biomass in a forest

D Pyramid of biomass in a sea

Correct Answer

Option D

Solution

(d) Pyramid of biomass in sea is inverted because biomass of consumers (zooplankton) is greater than phytoplankton producers.

Q16

Match the trophic levels with their correct species examples in grassland ecosystem.

A (iii) (ii) (i) (iv)

B (iv) (iii) (ii) (i)

C (i) (ii) (iii) (iv)

D (ii) (iii) (iv) (i)

Correct Answer

Option D

Solution

(d) T1-Grass; T2-Rabbit; T3-Crow; T4-Vulture.

Q17

Secondary productivity is rate of formation of new organic matter by

A Parasite

B Consumer

C Decomposer

D Producer

Correct Answer

Option B

Solution

(b) The rate of resynthesis of organic matter by the consumers is known as secondary productivity.

Q18

Which one of the following processes during decomposition is correctly described?

A Humification - Leads to accumulation of dark coloured humus which undergoes very fast microbial action

B Catabolism - Last step decomposition under fully anaerobic condition

C Leaching - Water soluble inorganic nutrients rise to the top layers of soil

D Fragmentation - Carried out by organisms such as earthworm

Correct Answer

Option D

Solution

(d) Fragmentation is breaking down detritus into smaller particles by detritivores like earthworm.

Q19

The mass of living material at a trophic level at a particular time is called :

A Standing state

B Net primary productivity

C Standing crop

D Gross primary productivity

Correct Answer

Option C

Solution

(c) Standing crop is the amount of living biomass in an ecosystem.

Q20

Most animals that live in deep oceanic waters are:

A secondary consumers

B tertiary consumers

C detritivores

D primary consumers

Correct Answer

Option C

Solution

(c) Detritivores are the organisms which feed on dead plants and animal residues.