Given below is an imaginary pyramid of numbers. What could be one of the possibilities about certain organisms at some of the different levels?                                                 

 
 

1.	Level PC is "insects" and level SC is "small insectivorous birds".
2.	Level PP is "phytoplanktons" in sea and "Whale" on top level TC
3.	Level PP is "pipal trees" and level SC is "sheep".
4.	Level PC is "rats" and level SC is "cats".

Which one of the following is not a functional unit of an ecosystem 
1. Energy flow
2. Decomposition
3. Productivity
4. Stratification

The upright pyramid of number is absent in      
1. Pond
2. Forest
3. Lake
4. Grassland

Identify the likely organisms (a), (b), (c) and (d) in the food web shown below:     

Options

The second stage of hydrosere is occupied by plants like :   
1. Azolla
2.Typha
3.Salix
4. Vallisneria

Natural reservoir of phosphorus is :    
1. Animal bones
2. Rock
3. Fossils
4.Sea water

Secondary productivity is rate of formation of new organic matter by:  
1. Parasite
2. Consumer
3. Decomposer
4. Producer

If 20 J of energy is trapped at producer level, then how much energy will be available to peacock as food in the following chain?                                                                        
plant → mice → snake → peacock
1. 0.02 J
2. 0.002 J
3. 0.2 J
4. 0.0002 J

Given below is a simplified model of phosphorus cycling in a terrestrial ecosystem with four blanks (A-D). Identify the blanks.                                                            

Options :

Match the following and select the correct option :  
(a) Earthworm                       (i) Pioneer species
(b) Succession                      (ii) Detrivore
(c) Ecosystem service           (iii) Natality
(d) Population growth            (iv) Pollination

     a       b       c      d
1. (i)      (ii)    (iii)    (iv)
2. (iv)     (i)    (iii)    (ii)
3. (iii)     (ii)   (iv)    (i)
4. (ii)      (i)    (iv)    (iii)