What percent of energy in the sunlight availble to the primary producers is converted by them into net primary productivity ?
1. 1
2. 2
3. 5
4. 10 

Both hydrach and xerarch successions:

1. Take same time

2. Have similar sere

3. Lead to mesic conditions

4. Have same pioneer species

The second trophic level in a lake is:

1. Phytoplankton

2. Zooplankton

3. Benthos

4. Fishes

The rate of formation of new organic matter by consumers is called as:

1. Secondary productivity
2. Standing crop
3. Standing state
4. Net primary productivity

The limitations of ecological pyramids include all the following except:

1. The do not take into account the same species belonging to two or more trophic levels

2. They do not represent relationships between organisms at different trophic levels

3. They assume a simple food chain and do not consider food webs

4. Saprotrophs are not given any place in the ecological pyramids

About what percent of the global carbon is contained in the atmosphere?

1. 71

2. 49

3. 17

4. about 1

Which of the following organisms will be the first to colonize a bare rock?

1. Annual plants

2. Lichens

3. Perennail plants

4. Herbs and shrubs

Most food chains are composed of 

1. 1 or 2 species

2. 3 or 4 species

3. 9 or 10 species

4. More than 16 species

The phosphorus cycle is unusual in that it is entirely:

1. Within aquatic ecosystems

2. Within terrestrial ecosystems

3. Sedimentary

4. Gaseous

Most primary productivity in the surface water of lakes and oceans is by:
1. Floating plants
2. Red and brown algae
3. Zooplankton
4. Phytoplankton