ECOSYSTEMS
2016 MARCH
1.
Nutrients
are never lost from the ecosystems and are recycled. Write about
a)
Gaseous
cycle
b)
Sedimentary
cycle (Scores:1+1)
2.
On earth,
life exists even in extreme and harsh conditions. Mention any two major biomes
in India. (Score:
1)
3.
Ecological
pyramids are usually upright. Meanwhile some, pyramid of biomass is inverted.
Explain the reason. (Scores: 2)
2016 SAY
1.
(a) Biogeochemical cycle is an important phenomenon
in very ecosystem. Describe phosphorus cycle. (Scores: 3)
OR
(b) The plant
communities in a given area show successive changes. Mention the stages of
succession in a xerosere.
2.
Earthworms are commonly referred as farmers’
friends. Define fragmentation. (Score 1)
MARCH 2017
1.
The
different stages of primary succession in water are represented below. Fill the
gaps that are unfilled.
(a) Phytoplankton
(b) ……………..
(c) Submerged free floating plant stage
(d) ……………..
(e) ……………..
(f) Shrub stage
(g) …………….. (Scores: ½ X 4 = 2)
2.
An
ecosystem consists of the following population:
Phytoplankton
Man
Fish
Zooplankton
Draw a
food chain denoting each trophic level. (Scores:
½ X 4 = 2)
MARCH 2018
1.
The
products of ecosystem processes are named as ecosystem services. list out any
four such services.
2.
Pyramid of
energy is never been inverted. Why?