Addition of which of the following can prevent leaching of minerals?
1. humus
2. mycorrhizae
3. rhizobia
4. calcium

Frog feeding on an herbivorous insect is:

Decomposers are   
1. Animalia and Monera
2. Protista and Animalia
3. Fungi and Plantae
4. Bacteria and Fungi

Which pair is mismatched  
1. Tundra –Permafrost
2. Savanna – Acacia trees
3. Prairie–Epiphytes
4. Coniferous forest – Evergreen trees

Highest value in g/${\mathrm{m}}^2$/yr of a grassland ecosystem would be 
1. Gross primary production
2. Net primary production
3. Secondary production
4. Tertiary production

An easily disturbed ecosystem which can recover after some time after the stoppage of  damaging factor is of
1. Low stability and high resilience
2. High stability and high resilience
3. Low stability and low resilience
4. High stability and low resilience

Which of the following is not used for construction of ecological pyramids  
1. Fresh weight
2. Dry weight
3. Number of individuals
4. Rate of energy flow

Highest annual net primary productivity is of  
1.Tropical deciduous forest
2. Temperate evergreen forest
3. Temperate deciduous forest
4. Tropical rain forest

Which one of the following types of organisms occupy more than one trophic level in a pond ecosystem.
1. Frog
2. Phytoplankton
3. Fish
4. Zooplankton

The biomass available for consumption by the herbivores and the decomposers is called   
1. Secondary productivity
2. Standing crop
3. Gross primary productivity
4. Net primary productivity