Ecosystem

Question 1

Factors affecting primary productivity

Answer 1

1.Environmental factors
(i) Sunlight
(ii) Temperarure
(iii) moisture
2. Nutrients Available
3. Photosynthesis efficiency

Question 2

Steps in Decomposition

Answer 2

(i) Fragmentation
(ii) Leaching
(iii) Catabolism
(iv) Humification
(v) Mineralisation

Question 3

Fragmentation

Answer 3

Process of breaking down detritus into smaller particles done by earthworms.

Question 4

Leaching

Answer 4

Process of water soluble inorganic nutrients getting washed down into the soil and precipitate as unavailable salts.

Question 5

Catabolism

Answer 5

The enzymatic action of fungus and bacteria on detritus into simple inorganic substances.

Question 6

Humification

Answer 6

Process of accumulation of dark amorphous substances called Humus that is highly resistant to microbial activity and undergoes decomposition at a very slow rate. Humus being colloidal is a reservoir of nutrients.

Question 7

Mineralization

Answer 7

The process of further degradation of humus by some microbial activity to release inorganic substances

Question 8

Factors affecting decomposition

Answer 8

1.Chenical composition of detritus
2.Climatic factors

Question 9

When is rate of decomposition slow?

Answer 9

When the detritus is risk in lignin and chitin
Low temp and
anaerobiosis inhibit decomposition

Question 10

When is rate of decomposition fast?

Answer 10

• When detritus is rich in nitrogen and water soluble substances like sugars
• Warm and most environment

Question 11

Food chain

Answer 11

The transfer of energy from producers to consumers through organisms

Question 12

Food web

Answer 12

A number of food chains are interconnected with each-other forming a web-like pattern is called food web

Question 13

Standing crop

Answer 13

Certain mass of living material at that particular time in the trophic level

Question 14

2nd law of thermodynamics in energy flow in ecosystem

Answer 14

Energy is transferred in an ecosystem in the form of food with energy loss as heat during metabolic activities and only a small fraction becomes stored as biomass. Constant supply of energy is needed.

Question 16

Limitations of ecological pyramids

Answer 16

1. Never takes into account of same species in 2 or more trophic levels
   2.