61. Pyramid of numbers in a pond ecosystem is
A
irregular
B
inverted
C
upright
D
spindle shaped
Answer :
upright
62. The second stage of hydrosere is occupied by plants like
A
Azolla
B
Typha
C
Salix
D
Vallisneria
Answer :
Vallisneria
63.
Given below is a simplified model of phosphorus cycling in a terrestrial ecosystem with four blanks (A-D). Identify the blanks:-
A
B
C
D
a.
Rock
Detritus minerals
Litter fall
Producers
b.
Litter fall
Producers
Rock
Detritus minerals
c.
Detritus minerals
Rock
Producers
Litter fall
d.
Producers
Litter fall
Rock
Detritus minerals
A
a
B
b
C
c
D
d
Answer :
c
64. Which of the following is the most stable ecosystem?
A
Forest
B
Desert
C
Mountain
D
Ocean
Answer :
Ocean
65. Which of the following ecological pyramids is generally inverted?
A
Pyramid of numbers in grassland
B
Pyramid of energy
C
Pyramid of biomass in a forest
D
Pyramid of biomass in a sea
Answer :
Pyramid of biomass in a sea
66. In an ecosystem, which one shows one-way passage
A
free energy
B
carbon
C
nitrogen
D
potassium
Answer :
free energy
67. Food chain in which micro-organisms breakdown the food formed by primary producers is
A
parasitic food chain
B
detritus food chain
C
consumer food chain
D
predator food chain
Answer :
detritus food chain
68. Second most important trophic level in a lake is
A
Zooplankton
B
Phytoplankton
C
Benthos
D
Neuston
Answer :
Zooplankton
69. Which of the following is a characteristic feature of cropland ecosystem ?
A
Absence of soil organisms
B
Least genetic diversity
C
Absence of weeds
D
Ecological succession
Answer :
Least genetic diversity
70. Which one of the following processes during decomposition is correctly described?
A
Humification-Leads to the accumulation of a dark coloured substance humus which undergoes microbial action at every fast rate
B
Catabolism-Last step decomposition under fully anaerobic condition
C
Leaching-Water soluble inorganic nutrients rise to the top layers of soil
D
Fragmentation-Carried out by organisms such as earthworm
Answer :
Fragmentation-Carried out by organisms such as earthworm