ECOSYSTEMS
2013 MARCH
1. Final community
that is in near equilibrium with environment in ecological succession is called
(1)
2. Natural
interlinked food chains are called (1)
3. A list of
organisms is given. Place them in different trophic levels. (2)
Grass, Man,
Fishes, Birds, Lion, Grasshopper, Zooplankton, Trees
2013 SAY
1. In the
equation, GPP – R = NPP; If NPP = Net
primary productivity. Explain GPP – R = NPP (2)
2. Which of the
following is a detritivore? (1)
1) Earthworm 2) Virus 3) Fox 4) Cow
2014 MARCH
1. The species
that invade a nude area are called ----------- species. In a primary succession
on rocls, the group that invade first are usually -------------- (1)
2. The rate of
biomass production in an ecosystem is called productivity. They are of 2 types,
gross primary productivity and net primary productivity. How these
productivities are related? (1)
3. A list of
different organisms in an ecosystem is given below. Arrange them in 1st,
2nd, 3rd and 4th trophic level. (2)
i. Phytoplankton ii.
Man
iii.
Fish iv. Zooplankton
2014 SAY
1.
By observing the relationship of the first pair fill
up the blanks:
a.
Grazing food chain consists of producers and
consumers whereas Detritus chain comprises dead organic matter and
---------------
b.
Nitrogen: Gaseous cycle Sulphur: ……………….. (½ + ½ =1)
2.
Field survey by a team of students recorded the
following data related to biomass of the organisms in each trophic level of an
ecosystem. Draw, name and explain the pyramid. (2)
3.
Gradual, sequential change of a given area including
species composition is known as ecological succession. If so name the first
stages of the succession in hydric area. (1)
2015 MARCH
1.
Given below are the components related to simplified
model of mineral cycling in a terrestrial ecosystem. Construct a flow chart.
[Hint:
weathering of rock] (Score: 2)
2.
Primary succession on rocks is known as Xerosere.
Answer the following related with Xerosere.
(a) Name the
pioneer community.
(b) Organic
acids have important roles in this succession. Justify. (Scores: 1 + 1 = 2)
2015 SAY
1.
By observing the relationship of first pair, fill up
the blanks.
a.
Net primary productivity = Gross primary
productivity – respiration
Gross primary
productivity is ………….
b.
Carbon: Gaseous cycle Phosphorus: ………….. (Score:
½ + ½ = 1)
2.
Field survey by a team of students recorded the
following data related to number of organisms in an ecosystem and plotted that
into a figure shown below:
Observe the
figure and explain the pyramid.
(Scores: 2)
3.
Hydrosere succession stages are given below. Arrange
them in order. (Scores: 1)
Scrub stage –
forest – submerged free floating – Marsh Meadow – Submerged stage – Reed swamp
– Phytoplankton