The given age pyramid represents a:
1. Fast expanding population
2. Slowly expanding population
3. Stable population
4. Declining population
The term "detritivore" includes
1. decomposers
2. primary consumers
3. secondary consumers
4. autotrophs
Which of the following statements is/are correct?
(a) The entire sequence of communities that successively change in a given area is called sere.
(b) The natural reservoir of phosphorus is rock.
(c) Ecological pyramids do not accommodate food web.
1. Only statement (a) is correct.
2. Only statement (b) is correct.
3. All (a), (b) and (c) are correct.
4. All (a), (b) and (c) are incorrect.
In most ecosystems, all the pyramids of number, energy and biomass are upright. It indicates that
(a) Producers are more in number and biomass than the herbivores.
(b) Herbivores are less in number and biomass than the carnivores.
(c) Energy at a lower tropic level is always more than at a higher level.
Choose the correct option.
1. Only (a) is correct.
2. Only (b) is correct.
3. Both (a) and (c) are correct.
4. Both (b) and (c) are correct.
In which part of the atmosphere ‘good ozone’ is found?
1. Troposphere 2. Stratosphere
3. Ionosphere 4. Exosphere
Choose the correct types of ecological pyramid on the basis of following data of dry weights.
(i) Secondary consumer - 11 kg/
(ii) Tertiary consumer - 1.5 kg/
(iii) Primary producer - 809 kg/
(iv) Primary consumer - 37 kg/
1. Upright pyramid of biomass.
2. Inverted pyramid of biomass.
3. Inverted pyramid of energy.
4. Upright pyramid of number.
During primary succession on rocks, pioneer species are
1. Annual grasses.
2. Perennial grasses.
3. Xerophytic shrubs.
4. Lichens.
Out of total cost of various ecosystem services, the soil formation accounts for about __A__, and contribution of other services like recreation and nutrient cycling, are less than __B__ each.
In the above statement for ‘A’ and ‘B’, which option is correct?
1. A – 6%, B – 10% 2. A – 50%, B – 10%
3. A – 10%, B – 50% 4. A – 10%, B – 6%
In terrestrial ecosystem, a much larger fraction of energy flows through______
1. GFC 2. DFC
3. Parasitic food chain 4. Both 1. and 3.
Read the following statements and choose the correct option
Statement-1 :Food webs provide stability to ecosystem.
Statement-2 : Food web operates because of taste
preference for particular food and unavailability of food.
1. Only statement (2) is correct.
2. Only statement (1) is correct.
3. Both statements are correct.
4. Both statements are incorrect
Read the statements given below and choose the correct option
Statement I: Decomposition is purely an anaerobic process.
Statement II: The rate of decomposition is controlled by chemical composition of detritus and climatic factors.
1. Only statement I is correct.
2. Only statement I is incorrect.
3. Both statements I and II are correct.
4. Both statements I and II are incorrect
What is the percentage of PAR (Photosynthetically active radiation) in incident solar radiation?
1. 50% 2. > 50%
3. 0% 4. < 50%
Rate of increase in biomass by heterotrophs or consumers per unit time and area is known as
1. Gross primary productivity
2. Net primary productivity
3. Secondary productivity
4. Community productivity
How many statements are correct about decomposition ?
(A) Oxygen independent process
(B) Faster if detritus is rich in lignin and chitin
(C) Light is most important climatic factor for decomposition
(D Warm and moist environment favour decomposition
1. One
2. Two
3. Three
4. Four
Which one of the following belongs to more than one trophic level ?
1. Grasshopper
2. Insectivorous plant
3. Cow
4. Lion
Which one of the following is wrong about primary succession ?
1. Lichen is pioneer community in lithosere
2. Formation of soil does not take place
3. The establishment of new biotic community is generally slow
4. With time water body is converted into land
According to Robert Constanza, the most expensive ecological service is :-
1. Purification of air
2. Soil formation
3. Nutrient cycling
4. Climate regulation
Death of organism is the beginning of food chain in which
1. Energy and nutrient requirement is met by degrading organic matter.
2. Major conduct for energy flow is operational in aquatic ecosystem.
3. Number of trophic levels are limited.
4. Producers belong to first carefully.
Which of the following organisms are abundant in the bottom of the pond?
1. Zooplanktons and actinomycetes.
2. bacteria, fungi and flagellates.
3. Phytoplanktons and flagellates.
4. Green algae, actinomycetes and flagellates.
Ecology is basically concerned with four levels of biological organization, which one of the following is
correct representation?
1. Population Ecosystem Biome Landscape.
2. Communities Population Ecosystem Biome.
3. Organisms Population Communities Biome.
4. Species Ecosystem Communities Biome.
Ecological niche is:
1. the surface area of the ocean
2. an ecologically adapted zone
3. the physical position and functional role of a species within the community
4. formed of all plants and animals living at the bottom of a lake
Formation of tropical forests needs mean annual temperature and mean annual precipitation as:
1. 18 – 25oC and 150 - 400cm
2. 5 – 15oC and 50 – 100 cm
3. 30 – 50oC and 100 – 150cm
4. 5 – 15oC and 100 – 200 cm
Out of the total cost of various ecosystem services which of the following account for about 50 per cent?
1. Soil formation
2. Nutrient cycling
3. Climate regulation
4. Habitat for wild life
The total energy available to the third trophic level organisms if ecosystem is supported by 10 lac J light energy
1. 10 J
2. 100 J
3. 1000 J
4. 10,000 J
Pioneer communities in ecological succession are
(i) Phytoplanktons (ii) Scrubs
(iii) Floating plants (iv) Lichens
(v) Herbs
1. (i), (ii), (iii), (iv)
2. (i), (iv)
3. (i), (iv), (v)
4. (i), (ii), (v)
An ecosystem is
1. Structural unit of nature.
2. Functional unit of nature.
3. Both 1 and 2.
4. Dynamic unit of nature.
Statements - 1 : In an ecosystem naturient is never lost.
Statement - 2 : Succession starts in an area where no living organisms are present.
Options
1. Both statements are correct.
2. Only 1 statements is correct.
3. Only 2 statements is correct.
4. Both incorrect.
Find incorrect statements
1. In an aquatic ecosystem, GFC is the major conduit for energy flow.
2. In terrestrial ecosystem, DFC is is the major conduit for energy flow.
3. In nature food chain always works in isolation.
4. Even DFC & GFC is linked in nature.
Humus is
A. Dark coloured amorphous substance.
B. Highly resistant to microbial action.
1. Both A and B are correct.
2. Both A and B are incorrect.
3. A is correct but B is incorrect.
4. A is incorrect but B is correct.
The natural reservoir for phosphorus is
1. Ocean
2. Rock
3. Atmosphere
4. Living organisms