- Consider the following statements and select the correct
option stating which ones are true (T) and which ones are
false (F).
(i) Pyramid of biomass is upright in forest ecosystem and
inverted in grassland ecosystem.
(ii) Pyramid of numbers is inverted in grassland and
upright in aquatic ecosystem.
(iii) Pyramid of energy depicts the rate of energy flow or
productivity at successive trophic levels.
(iv) Ecological pyramids have no place for detritivores and
decomposers though they play important role in an
ecosystem.
(i) (ii) (iii) (iv)
(a) F F T T
(b) T F T T
(c) F T F F
(d) T F F T - Among the following, maximum productivity occurs in
(a) grassland (b) tropical forest
(c) estuaries (d) desert. - What will happen if decomposers are completely removed
from the ecosystem?
(a) There will be no energy flow.
(b) There will be an increase in the number of detritivores.
(c) Herbivores will not receive solar energy.
(d) The movement of minerals in an ecosystem will be
blocked. - Consider the following statements and select the correct
option that fill in the blanks.
I. food chain begins with host and usually
ends in parasite.
II. The sequence of successional stages on sand is known
.
III. Breaking down of detritus into small particles by
earthworm is called _____.
I II III
(a) Grazing lithosere catabolism
(b) Auxiliary psammosere fragmentation
(c) Detritus psammosere mineralisation
(d) Parasitic lithosere humification - Read the given statements and select the correct option.
Statement A : Net primary productivity is the amount of
organic matter stored by producers per unit time and per
unit area.
Statement B : Net productivity decreases with each
trophic level.
(a) Both statements A and B are correct and B is the correct
explanation of A.
(b) Both statements A and B are correct but B is not the
correct explanation of A.
(c) Statement A is correct but statement B is incorrect.
(d) Both statements A and B are incorrect. - Which of the following constitutes microecosystem?
(a) Aquarium (b) Pond
(c) Log of wood (d) Kitchen garden - Food web
(a) reduces adaptability and competitiveness of the
organisms
(b) is monophagous
(c) consists of number of food chains interlinked at various
trophic levels
(d) both (b) and (c). - The fraction of energy lost when an organism proceeds from
one trophic level to the next trophic level is
(a) 10 percent (b) 20 percent
(c) 30 percent (d) 90 percent. - Match the following and select the correct option.
Column I Column II
A. Lichen stage (i) Heteropogon
B. Moss stage (ii) Rhizocarpon
C. Shrub stage (iii) Grimmia
D. Perennial grass stage (iv) Rubus
(a) A-(ii); B-(iii); C-(iv); D-(i)
(b) A-(ii); B-(iii); C-(i); D-(iv)
(c) A-(iii); B-(iv); C-(ii); D-(i)
(d) A-(iv); B-(iii); C-(i); D-(ii) - Which of the given pyramid is always upright?
(a) Pyramid of energy (b) Pyramid of biomass
(c) Pyramid of numbers (d) Both (a) and (b) - Manthan Patel
- D.B. Rakshit Narayanan - Anna Nagar,
Chennai
October-2017
OCTOBER 2017 Winners
1-g- AMPHETAMINES 2-i- EPISTASIS
3-f- HELICOTREMA 4-j- AMENSALISM
5-e- THELYTOKY 6-d- CARYOPSIS
7-c- OSTEOMALACIA 8-h- OOPHORITIS
9-b- CHOANODERM 10-a-POLYCYTHEMIA
Winners : Sankhadeep Das, Purba Medinipur (West Bengal), Gayatri Prabhu, Bhramagiri
circle (Udupi), Abhishek Serrao, Chikmagalur, (Karnataka), Suman Kumar Ojha,
Chikanpara (West Bengal), Soumyadeep dutta