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 rate of formation of new organic matter by rabbits in grassland is called:
1. Net productivity
2. Secondary productivity
3. Net primary productivity
4. Gross primary productivity

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)

Vertical distribution of different species occupying different levels in a biotic community is known as:                                                                                                       
1. Stratification
2. Zonation
3. Pyramid
4. Divergence