Fill in the blanks:

1. Plants are called as ____ because they fix carbon dioxide.
2. In an ecosystem dominated by trees, the pyramid (of numbers) is ____ type.
3. In aquatic ecosystems, the limiting factor for the productivity is ____.
4. Common detritivores in our ecosystem are ____.
5. The major reservoir of carbon on earth is ____.

Which one of the following has the largest population in a food chain?

1. Producers
2. Primary consumers
3. Secondary consumers
4. Decomposers

The second trophic level in a lake is

1. Phytoplankton
2. Zooplankton
3. Benthos
4. Fishes

Secondary producers are

1. Herbivores
2. Producers
3. Carnivores
4. None of the above

What is the percentage of photosynthetically active radiation (PAR) in the incident solar radiation?

1. 100 %
2. 50 %
3. 1-5 %
4. 2-10 %

Describe between

1. Grazing food chain and detritus food chain
2. Production and decomposition
3. Upright and inverted pyramid
4. Food chain and Food web
5. Litter and detritus
6. Primary and secondary productivity

Describe the components of an ecosystem.

Define ecological pyramids and describe with examples, pyramids of number and biomass.

What is primary productivity? Give brief description of factors that affect primary productivity.

Define decomposition and describe the processes and products of decomposition.

Give an account of energy flow in an ecosystem.

Write important features of a sedimentary cycle in an ecosystem.

Outline salient features of carbon cycling in an ecosystem.