Wednesday, 4 November 2015

ECOLOGY-ECOSYSTEM : ASSIGNMENT


CLASS-XII

ASSIGNMENT

ECOLOGY-ECOSYSTEM

 

Q.(1)                        Name the pioneer species organism on bare rocks and water body.

How do these species help in establishing the next type of Vegetation.

 

Q.(2)           Under what circumstances secondary succession begins? Why does it proceed faster than primary succession?

 

Q.(3)           What functions do detritivors play in ecosystems? Explain the significance of humification and mineralisation in a decomposition cycle?

 

Q.(4)           Compare the grazing food chain and detritus food chain in aspect of their  (a)origin  (b)  Energy status.

 

 

Q.(5)           Differentiate between primary and secondary succession.

 ( Any four points)

 

Q.(6)          What is meant by ecological succession? How does it occur? Explain.

 

 

 Q.(7)         Name the type of food chains responsible for the flow of larger fraction of energy in an aquatic and terrestrial ecosystem respectively. Mention difference between the food chains.

                  (Hint-Aquatic (GFC) Terrestrial (DFC) ).

 

Q.(8)          Write down the difference between net primary productivity and GPP.

 

Q.(9)          (a)  Draw pyramid of numbers of a situation where a large population of insect feed upon a big tree. The insects in turn are eaten by small birds which in turn are fed up by big birds.

                  (b)  Differentiate giving reason between the pyramid of biomass of above situation and pyramid of numbers you have drawn.

 

 

 

 

 

 

Q.(10)        Identify the type of the given ecological pyramid and give one example each of pyramid of numbers and pyramid of biomass in such cases.

                  Ans.     Inverted pyramid.

                  Inverted pyramid of biomass in lake.

- - - - - - Phytoplankton - - - - - - -zooplankton- - - - - - -fishes.

Inverted pyramid of Numbers.

Tree - - - - - - Insects - - - - - - - Birds.

 

Q.(11)        The energy flow in ecosystem follows second law of thermodynamics. Explain (LA  Questions)

 

Q.(12)        Distinguish between

                  (a)        Production and decomposition.

                  (b)        Upright and inverted pyramid.

                  (c)        Food chain & food web.

                  (d)        Litter and detritus.

                  (e)        Fragmentation and leaching.

                  (f)        Hydrarch succession and Xerarch  succession.
            (g)        Carbon cycle and phosphorous cycle

No comments:

Post a Comment