Which ecosystem has the maximum biomass?

(1) Forest ecosystem 

(2) Grassland ecosystem 

(3) Pond ecosystem 

(4) Lake ecosystem 

Which one of the following is a characteristic feature of cropland ecosystem?

(1) Least genetic diversity

(2) The absence of weeds

(3) Ecological succession

(4) The absence of soil organisms

Identify the possible link A in the following food chain

Green plant -> Insect -> Frog -> A -> Eagle

1. rabbit                         

2. wolf

3. cobra                         

4. parrot

The correct sequence of plants in a hyrdosere is 

1. Oak→Lantana →Scirpus→Pistia→Hydrilla→Volvax
2. Volvax→Hydrilla→Pistia→Scirpus→Lantana→Oak
3. Pistia→Volvax→Scirpus→Hydrilla→Oak→Lantana
4. Oak →Lantana→Volvax→Hydrilla→Pistia→Scirpus

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

1. Littoral

2. Limnetic

3. Benthic

4. Profundal