Photosynthesis is absent in 

1. aphotic layer                 

2. photic layer        

3. benthic layer                 

4. pelagic layer.

The given type of ecological pyramid represents

1. pyramid of numbers in tree ecosystem

2. pyramid of biomass in a fallow land 

3. pyramid of biomass in a lake

4. energy pyramid in a spring

Which of the following zones of a lake is habitat for snails, slugs and microorganisms?

1. Littoral

2. Limnetic

3. Benthic

4. Profundal

Mr. X is eating curd/yoghurt. For this food intake in a food chain he should be considered

as occupying

1. first trophic level

2. second trophic level

3. third trophic level

4. fourth trophic level.

What is PAR range?

(1) 200 nm - 800 nm          

(2) 400 nm - 700 nm

(3) 350 nm - 550 nm         

(4) 600 nm - 100 nm

The bacteria which attack dead animals are 
(1) first link of the food chain and are known as primary producers.

(2) Second link of the food chain and are herbivorous

(3) third link of the food chain and are tertiary consumers

(4) the end of food chain and are decomposers.

Animals take phosphorous from 
(1) water 

(2) plants

(3) rock 

(4) soil.

Most animals that live in deep oceanic waters are

(1) Tertiary consumers

(2) Detritivores

(3) Primary consumers

(4) Secondary consumers

Keystone species deserve protection because these

(1) are capable of surviving in harsh environmental conditions

(2) indicate presence of certain minerals in the soil

(3) have become rare due to overexploitation

(4) play an important role in supporting other species.

Energy flow in an ecosystem is 

(1) unidirectional

(2) bidirectional

(3) multi-directional

(4) All the these