Which vertical strata is occupied by trees in a forest?
Top
Middle
Bottom
Any of the above.
Which of the following could affect the rate of function of a pond?
The solar input
The cycle of temperature
Day-length
All of the above
The basic requirement for any ecosystem to function and sustain is
Enormous amount of water
Constant input of solar energy
Fertile soil
Oxygen
The amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis is called as-
Biomass production
Primary production
Secondary production
Assimilation
Primary production is expressed in terms of-
Grams
Grams/year
Gram/m2
Gram/m2/year
What do you mean by Productivity?
Rate of biomass production
Amount of biomass production
Biomass produced in an area
Biomass produced in a time period
Secondary productivity is defined with respect to-
Producers
Consumers
Ratio of producers and consumers
Trophic level
Primary productivity of an terrestrial ecosystem depends upon
Photosynthetic capacity of plants.
A variety of environmental factors,
Availability of nutrients
All of the above.
What is the annual net primary productivity of the whole biosphere
160 billion tons
170 billion tons
177 billion tons
190 billion tons
Which of the following contributes the maximum to the net primary productivity?
Ocean ecosystem
Land ecosystem
Pond ecosystem
Man-made ecosystem
Why do we call the earthworm as the farmer’s friend?
It eats the pests
It prevents the growth of weeds
Makes the soil fertile by burrowing
They help in the breakdown of complex organic matter as well as in loosening of the soil.
Which of the following is not a step in the process of decomposition?
Fragmentation
Leaching
Anabolism
Humification.
What is the process by which Detritivores break down the detritus into smaller particles.?
Degradation
Decomposition
What does the process of leaching refers to-
Accumulation of a dark coloured amorphous substance
Organic solvents reabsorbed by the plants
Inorganic solvents get precipitated out of the soil
Water soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts.
In the process of decomposition ‘catabolism’ is performed by-
Earthworms
Bacteria
Bacteria and fungi
Fungi
Which of the following is the substrate in the process of mineralisation?
Detritus
Humus
Organic matter
None of the above
Which of the following does not affect rate of decomposition?
Substrate composition
Soil moisture
Temperature of soil
CO₂
Decomposition would be fast if the detritus contains-
Cellulose
Lignin and chitin
Nitrogen and water soluble sugars
Cellulose and pectin
Which of the following promotes the process of decomposition?
Warm and moist environment
low temperature
Anerobiosis
Lignin and chitin rich detritus
What is the source of energy for all ecosystems on Earth?
Sun
Hydrothermal vents
Lava
Both ‘1’ and ‘2’
What percentage of the incident solar radiation is photosynthetically active radiation (PAR)?
50%
Less than 50%
More than 50%
10%
What proportion of the PAR (photosynthetically active radiation) is captured by plants?
1 - 10%
2 - 10%
5 - 15%
5 - 25%
Which are the primary consumers in a grazing food chain?
Carnivores
Herbivores
Detrivores
Omnivores
What do secondary carnivores refer to?
Animals at second trophic level
Those animals that depend on the herbivores for food
Those animals that depend on the primary carnivores for food
Those animals that depend on the secondary herbivores for food
The detritus food chain (DFC) begins with________________. It is made up of decomposers which are ______________organisms, mainly________________. They meet their energy and nutrient requirements by degrading ______________.
detritus, heterotrophic, earthworm and dead organic matter.
dead organic matter, heterotrophic, fungi and bacteria, dead organic matter.
dead organic matter, autotrophic, fungi and plants, dead organic matter.
grass, heterotrophic, fungi and bacteria, dead organic matter.
What is the major conduit for energy flow in an aquatic ecosystem?
Grazing food chain
Detritus food chain
Identify the odd one out.
Cockroach
Crow
Humans
Goat
“Detritus food chain may be connected with the grazing food chain at some levels” this is evident from(i). Some of the organisms of DFC are prey to the GFC animals(ii). In a natural ecosystem, some animals like cockroaches, crows, etc., are omnivores.(iii). Some of the organisms of GFC are facultative decomposers
i and iii
i and ii
ii and iii
i only
What do you mean by a foodweb?
Group of food chains.
Food chains present in a particular area
Natural interconnection of food chains
Food chains formed by members of a genus
Based on the source of organism’s nutrition or food, they occupy a specific place in the food chain that is known as-
Strata
Sere
Chain level
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