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

Which of the following is the functional unit of nature?
a. A plant
b. An animal
c. Ecosystem
d. Environment

Identify the odd one out?
a. Forest
b. Grassland
c. Desert
d. Wetland

Which of the following is not a man-made ecosystem?
a. Pond
b. Crop-field
c. Swimming pool
d. Both ‘a’ and ‘c’

Vertical distribution of different species occupying different levels is called as-
a. Vertification
b. Stratification
c. Succession
d. Layering

Which vertical strata is occupied by trees in a forest?
a. Top
b. Middle
c. Bottom
d. Any of the above.

Which of the following could affect the rate of function of a pond?
a. The solar input
b. The cycle of temperature
c. Day-length
d. All of the above

The basic requirement for any ecosystem to function and sustain is
a. Enormous amount of water
b. Constant input of solar energy
c. Fertile soil
d. Oxygen

The amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis is called as-
a. Biomass production
b. Primary production
c. Secondary production
d. Assimilation