Ecosystem

Which one of the following processes during decomposition is correctly described ?

1. Catabolism – Last step in the decomposition under fully anaerobic condition
2. Leaching – Water soluble inorganic nutrients rise to the top layers of soil
3. Fragmentation – Carried out by organisms such as earthworm
4. Humification – Leads to the accumulation of a dark coloured substance humus which undergoes microbial action at a very fast rate

Which one of the following is a primary consumer in maize field ecosystem ?

1. Phytoplankton
2. Lion
3. Grasshopper
4. Wolf

When man eats fish which feeds on zooplankton which have eaten small plants, the producer in the chain is :

1. Zooplankton
2. Fish
3. Small plants
4. Man

The rate of formation of new organic matter by rabbit in a grassland, is called :

1. Net productivity
2. Gross primary productivity
3. Secondary productivity
4. Net primary productivity

The second stage of hydrosere is occupied by plants like

1. Vallisneria
2. Typha
3. Azolla
4. Salix

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

1. (a) deer, (b) rabbit, (c) frog, (d) rat
2. (a) squirrel, (b) cat, (c) rat, (d) pigeon
3. (a) dog, (b) squirrel, (c) bat, (d) deer
4. (a) rat, (b) dog, (c) tortoise, (d) crow

Which one of the following is not a gaseous biogeochemical cycle in ecosystem?

1. Sulphur cycle
2. Nitrogen cycle
3. Phosphorus cycle
4. Carbon cycle

Identify the possible link "A" in the following food chain: Plant insect frog "A" Eagle

1. Wolf
2. Rabbit
3. Cobra
4. Parrot

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

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

Which one of the following is not a functional unit of an ecosystem?

1. Energy flow
2. Decomposition
3. Productivity
4. Stratification