In general, the biomass in an ecosystem will be greatest at the trophic level comprising.

1. secondary consumers

2. primary consumers

3. producers

4. tertiary consumers

Consider the following two statements:

l. The annual net primary productivity of the whole biosphere is approximately 170 billion tons (dry weight) of organic matter.

ll. Majority of this is contributed by the oceans as they occupy larger area of earth.

1. Both l and ll are correct and ll explains l
2. Both l and ll are correct but ll does not explain l
3. l is correct but ll is incorrect
4. l is incorrect but ll is correct

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

During the stages of succession in a given ecosystem the following changes in characteristics may be observed:
Characteristic                              Stages in ecosystem development
                                                         Early                           Late
A. Total matter                                   Low                             High
B. Species diversity                             Low                             High
C. Size of organism                             Small                           Large
D. Productivity                                    Low                              High
E. Food chains                                    Short                            Long
Which one of the characteristics, A, B, C, D or E is responsible for the apparent high degree of stability associated with a climax ecosystem?
(1) B             

(2) D               

(3) A             

(4) E

Some of the stages in the hydrarch are labelled as:
A. Marsh meadow stage
B. Reed swamp stage
C. Submerged plant stage
D. Phytoplankton stage
E. Submerged free floating plant stage
Identify the choice that represents the correct sequence of these stages:
(1) D, C, E, B and A

(2) C, E, A, B and D
(3) B, D, C, A and E

(4) D, E, C, B and A