Question: From NCERT NEET Derived PYQ
At the trophic level of consumers, the rate at which food energy is assimilated, is called:
1. Secondary productivity
2. Gross primary productivity
3. Net primary productivity
4. Net secondary productivity
Answer ▽
1. Secondary productivity
In a food chain, energy stored at the producer level is called as primary productivity. Energy stored at the consumer level is called as secondary productivity. It is the rate of energy storage at consumer level. Consumer level includes herbivores, carnivores and decomposers. Gross primary productivity is the rate of photosynthesis. Net primary productivity is the rate of storage of organic matter except which is utilized for the respiration by plants. Net productivity is the rate of storage of organic matter which is not used by the consumers,
Thus, the correct answer is 'Secondary productivity.'
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Question: From NCERT NEET Derived PYQ
Which trophic level is incorrectly defined?
1. Carnivores- secondary or tertiary consumer
2. Decomposer- microbial heterotrophs
3. Herbivores - primary consumer
4. Omnivores - Molds, yeast and mushrooms
Answer ▽
4
😁mushroom is a carnivore.
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Question: From NCERT NEET Derived PYQ
Consider the following two statements:
l. The annual net primary productivity of the whole biosphere is approximately 170 billion tons (dry weight) of organic matter.
ll. Majority of this is contributed by the oceans as they occupy larger area of earth.
1. Both l and ll are correct and ll explains l
2. Both l and ll are correct but ll does not explain l
3. l is correct but ll is incorrect
4. l is incorrect but ll is correct
Answer ▽
3. l is correct but ll is incorrect
The annual net primary productivity of the whole biosphere is approximately 170 million tons (dry weight ) of organic matter.
Of this, despite occupying about 70 percent of the surface, the productivity of oceans are only 55 million tons.
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Question: From NCERT NEET Derived PYQ
Assertion: The annual net primary productivity of the whole biosphere is approximately 170 million tons (dry weight ) of organic matter.
Reason: Of this, despite occupying about 70 percent of the surface, the productivity of oceans are only 55 million tons.
Answer ▽
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Question: From NCERT NEET Derived PYQ
Both hydrach and xerarch successions:
1. Take same time
2. Have similar sere
3. Lead to mesic conditions
4. Have same pioneer species
Answer ▽
3. Lead to mesic conditions
Xerach succession takes place in dry areas and the series progress from xeric to mesic condition. Hence, both hydrach and xerach succession leads to medium water conditions (mesic).
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Question: From NCERT NEET Derived PYQ
The rate of formation of new organic matter by consumers is called as:
1. Secondary productivity
2. Standing crop
3. Standing state
4. Net primary productivity
Answer ▽
1. Secondary productivity
Primary productivity is the rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances.
The rate at which the consumers convert the chemical energy of their food into their own biomass is called secondary productivity.
A standing crop is the total dried biomass of the living organisms present in a given environment.
Net primary production is the rate at which all the plants in an ecosystem produce net useful chemical energy.
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Question: From NCERT NEET Derived PYQ
The limitations of ecological pyramids include all the following except:
1. The do not take into account the same species belonging to two or more trophic levels
2. They do not represent relationships between organisms at different trophic levels
3. They assume a simple food chain and do not consider food webs
4. Saprotrophs are not given any place in the ecological pyramids
Answer ▽
2. They do not represent relationships between organisms at different trophic levels
pyramid is a graphical representation of the relation between the different living organisms and number of organisms, biomass, and productivity at various trophic levels in an ecosystem and these types of pyramids are known as ecological pyramids.
Three main kinds of ecological pyramids are of energy, biomass, and numbers.
Some limitations of the pyramids are:-
a) More than one species may occupy multiple trophic levels in case of food web.b) Pyramids do not consider the possibility of the existence of the same species at different levels.
c) The saprophytes are not considered in any of the pyramids.
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Question: From NCERT NEET Derived PYQ
Which of the following is not a limitation of the pyramid?
a) It does not take into account the same species belonging to two or more trophic level
b) It does not accommodate a food chain
c) It does not accommodate a food web
d) None of these
Answer ▽
correct option is A- It does not take into account the same species belonging to two or more trophic levels.
pyramid is a graphical representation of the relation between the different living organisms and number of organisms, biomass, and productivity at various trophic levels in an ecosystem and these types of pyramids are known as ecological pyramids.
Three main kinds of ecological pyramids are of energy, biomass, and numbers.
Some limitations of the pyramids are:-
a) More than one species may occupy multiple trophic levels in case of food web.
b) Pyramids do not consider the possibility of the existence of the same species at different levels.
c) The saprophytes are not considered in any of the pyramids.
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Question: From NCERT NEET Derived PYQ
Most food chains are composed of
1. 1 or 2 species
2. 3 or 4 species
3. 9 or 10 species
4. More than 16 species
Answer ▽
2. 3 or 4 species
Ecosystems with fewer species may have a food chain with three trophic levels.
The first trophic level are the primary producers. The next three trophic level are called the consumers.
So the correct option is '3 or 4 species'.
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Question: From NCERT NEET Derived PYQ Vertical distribution of different species occupying different levels in a biotic community is
known as
1. divergence
2. stratification
3. zonation
4. pyramid
Answer ▽
2. stratification
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Question: From NCERT NEET 2015 Derived PYQ
Secondary succession takes place on/in
(1) bara rock
(2) degraded forest
(3) newly created pond
(4) newly cooled lava
Answer ▽
(2) degraded forest
In an ecological community, the process of succession changes the structure of the species, over a time period.
In an ecosystem, there are mainly two types of succession, namely primary and secondary. There is a marked difference in the types of ecosystems, both these succession patterns occur.
During secondary succession, there is a development of a community on an ecosystem that was previously occupied or colonized. The ecosystem would have been damaged or destroyed. The areas where this kind of succession takes place will be a woodland, after continuous felling of trees. Or a grassland affected by the fire. During secondary succession, the ecosystem tries to rejuvenate the lost resources. Thus from the above-given options, the example for secondary succession to take place is a degraded forest.
The process of secondary succession is more rapid and less time consuming than primary succession. This is due to the fact that the soil already contains organic matter which makes it easier for life to develop again.
Considering the other given options:
A newly created pond is an example of primary succession since it is a new habitat and life is yet to be formed in it for the first time. Thus secondary succession cannot take place in it.An area with newly cooled lava cannot be the site for secondary succession, since it was not inhabitable before cooling down. Thus it is also an example for primary succession.
Bare rock is also an example of an ecosystem with primary succession since life is yet to be formed by utilizing the organic materials on it.
Thus by considering the given options, the most appropriate one was found to be 2, that is, secondary succession takes place in a degraded forest.
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Question: From NCERT NEET 2015 Derived PYQ The mass of living material at a tropic level at a particular time is called
(1) gross primary productivity
(2) stading state
(3) net primary producitivity
(4) standing crop
Answer ▽
(4) standing crop
Solution
The total dried biomass of living organisms present at a trophic level at a particular time is known as standing crop.
Standing state is the amount of inorganic (non-living) nutrients present at any time in the soil or water of ecosystem.
The gross primary productivity is the total organic matter synthesised by producers during photosynthesis per unit time and area
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Question: From NCERT NEET 2014 Derived PYQ
If 20 J of energy is trapped at producer level, then how much energy will be available to peacock as food in the following chain?
Plant MiceSnakePeacock
(1) 0.02 J
(2) 0.002 J
(3) 0.2 J
(4) 0.0002 J
Answer ▽
(1) 0.02 J
It is called 10% law which was proposed by Lindeman. Accordingly, if plant trapped 20 J of energy, mice will have 2 J, snake will have 0.2 J and hence, peacock will have 0.02 J of energy.
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Question: From NCERT NEET 2013 Derived PYQ Which one of the following processes during decomposition is correctly described?
1. Fragmentation-Carried out by organisms such as earthworm
2. Humification-Leads to the accumulation of a dark coloured substance humus, which
undergoes microbial action at a very fast rate
3. Catabolism-Last step in the decomposition under fully anaerobic condition
4. Leaching-Water soluble inorganic nutrients rise to the top layers of soil.
Answer ▽
1. Fragmentation-Carried out by organisms such as earthworm
> Option 4, Leaching is a process where an ore is treated with chemicals to convert the valuable metals within the ore, into soluble salts but impurities remain insoluble.
> Option 1, Fragmentation is a form f asexual reproduction in multi-cellular organisms. In this process the organisms like earthworm, hydra etc. split into fragments. It in general can be defined as a process of breaking down into smaller subunits so that it can be decomposed.
Note: The meaning of fragmentation is being broken into sections. For example the Spirogyra undergoes fragmentation which results in numbers of filaments and every filament grows into mature filament or organism. So, the meaning of fragmentation is different in different aspects.
> Option 2, Humification is a process of formation of organic matter that has reached maturity (also called humic substances) decomposed from plant remains.> Option 3, Catabolism is the process that breaks down molecules into smaller units by the set of metabolic pathways. Those smaller units that are either oxidized and release the energy or used in other anabolic reactions.
Thus, we can conclude that fragmentation is the process in which breakdown of materials is carried out by different organisms like earthworms.
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Question: From NCERT NEET Derived PYQ
Which one of the following is not a gaseous biogeochemical cycle in ecosystem?
1. Oxygen cycle
2. Phosphorus cycle
3. Nitrogen cycle
4. Carbon cycle
Answer ▽
-Gases or vapors are the products involved in the circulation of biotic and abiotic elements of the biosphere in the gaseous processes of substances and the reservoir pool is the atmosphere or hydrosphere, e.g. carbon, hydrogen, oxygen, nitrogen, etc.
-The Phosphorus cycle: Phosphorus is a key component of biological membranes, nucleic acids, and processes for the transfer of cellular energy. To make shells, bones, and teeth, many animals always need massive volumes of this ingredient. Wherein the natural phosphorus reservoir is the rock which, in the form of phosphates, contains phosphorus. In soil solution, minute quantities of these phosphates dissolve as rocks are weathered and are consumed by the plant roots. The materials involved in circulation between biotic and abiotic elements of the biosphere are non-gaseous in sedimentary cycles of matter, and the reservoir pool is the lithosphere, e.g. phosphorus, calcium, magnesium, etc.
-Sulphur has sedimentary as well as gaseous phases. As compared to sedimentary cycles, gaseous cycles are rapid and more perfect.-In the gaseous form, nitrogen, carbon, and oxygen are present in the atmosphere. The sedimentary cycles are the calcium cycle, the sodium cycle, the phosphorus cycle, the iron cycle, the magnesium cycle, and the Sulphur cycle.
Thus, choice B is the correct answer.
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Question: From NCERT NEET 2011 Derived PYQ
Mass of living matter at a trophic level in an area at any time is called
1. Detritus
2. Humus
3. Standing state
4. Standing crop
Answer ▽
4. Standing crop
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Question: From NCERT NEET 2011 Derived PYQ Of the total incident solar radiation the proportion of PAR is
1. about 60%
2. less than 50%
3. more than 80%
4. about 70%
Answer ▽
2. less than 50%
The source of energy in all ecosystem is solar energy. About 50% of the solar energy incident over earth is present in PAR (Photosynthetically active radiation). About 1 -5% of incident solar radiation or 2 - 10% of PAR is captured by the photosynthetic organisms in the synthesis of organic matter (gross primary productivity).
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Question: From NCERT NEET 2010 Derived PYQ
Which one of the following is one of the characteristics of a biological community ?
1. Stratification
2. Natality
3. Mortality
4. Sex-ratio
Answer ▽
1. Stratification
Stratification is the characteristic of biological community. Stratification is the vertical layering or the phenomenon of having more than one stratum including formed by different plants/organisms in the same place. A forest may have 5-7 strata including large or canopy trees, medium tees, short trees, shrubs, herbs, ground flora etc. Stratification is useful as it can accommodate a large number of organisms of different types and more efficient use of resources. The animals that occupy such similar strata or ecological niches although geographically seperated are called ecological equivalents.
Natality, mortality. age structure and sex-ratio are the basic characteristics of a population.
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Question: From NCERT NEET 2010 Derived PYQ
About 70% of total global carbon is found in
1. grasslands
2. agro-ecosystems
3. oceans
4. forests
Answer ▽
3. oceans
Oceans occupy 70% of the earth’s surface. Carbons are mainly found in the form of organic compounds within living organisms. Carbon is responsible for regulating the temperature of the earth that provides us a life-friendly environment. It is also a major component of our food. The ocean comprises plentiful ecosystems. A major number of living species are found in the oceans. The carbon dioxide content of the oceans is 50% higher than the atmosphere. The majority of the global carbon is stored in the rocks, sediments, living organisms, and in the ocean. Thus it comprises 70% of the global carbon. The ocean is known as the giant carbon sink as it absorbs the majority of the environmental carbon. In the oceans, the carbons travel from the sea surface to the atmosphere by a continuous process.
The cyclic movement of carbon atoms from the atmosphere to the organism and again to the atmosphere is called the carbon cycle. As the earth and its atmosphere remain in a closed environment, the quantity of carbon remains unchanged. It only travels from one level to another level.
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Question: From NCERT NEET AIIMS - 2010 Derived PYQ
Animals take phosphours from
(1) water
(2) plants
(3) rock
(4) soil.
Answer ▽
(2) plants
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Question: From NCERT NEET AIIMS - 2012Derived PYQ
Energy flow in an ecosystem is
(1) unidirectional
(2) bidirectional
(3) multi-directional
(4) All the these
Answer ▽
1. unidirectional
According to Lindeman’s law of energy, 10% of energy is transferred from one level of ecological pyramid to another level. Because most of the energy is released in the form of heat and it is also utilized in performing the metabolic activities of organisms. That’s why there will be transferring of less energy from one trophic level to another trophic level. And the organisms which are found at the top most trophic level will get less energy as compared to previous trophic levels.
Hence, we can say that the less energy is transferred to the next trophic level. That’s why the flow of energy in an ecosystem is described as the direction of energy from the sun to the producer and then to the next level of the pyramid of energy.
That’s why flow of energy in the ecosystem is unidirectional in nature. Energy flow in an ecosystem is always unidirectional in nature because most of energy is released at the trophic level in the form of heat and performing metabolic activities. Hence 10% is transferred from one trophic level to another.
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Question: From NCERT NEET Derived PYQ
Most of the world's carbon is found:
(1) As carbon dioxide in the atmosphere.
(2) In living organisms.
(3) As bicarbonate and carbonate ions dissolved in the oceans.
(4) As carbonate minerals in sedimentary rock.
Answer ▽
(3) As bicarbonate and carbonate ions dissolved in the oceans.
| Pool | Quantity (gigatons) |
|---|---|
| Atmosphere | 720 |
| Ocean (total) | 38,400 |
| Total inorganic | 37,400 |
| Total organic | 1,000 |
| Surface layer | 670 |
| Deep layer | 36,730 |
| Lithosphere | |
| Sedimentary carbonates | > 60,000,000 |
| Kerogens | 15,000,000 |
| Terrestrial biosphere (total) | 2,000 |
| Living biomass | 600 – 1,000 |
| Dead biomass | 1,200 |
| Aquatic biosphere | 1 – 2 |
| Fossil fuels (total) | 4,130 |
| Coal | 3,510 |
| Oil | 230 |
| Gas | 140 |
| Other (peat) | 250 |
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Question: From NCERT NEET Derived PYQ
The phosphorus cycle differs from the carbon cycle in that:
a. Phosphorus does not enter living organisms, whereas carbon does.
b. The phosphorus cycle does not include a gaseous phase, whereas the carbon cycle does.
c. The phosphorus cycle includes a solid phase, whereas the carbon cycle does not
d. The primary reservoir of the phosphorus cycle is the atmosphere, whereas the primary reservoir for the carbon cycle is in rock.
Answer ▽
b. The phosphorus cycle does not include a gaseous phase, whereas the carbon cycle does.
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Question: From NCERT NEET Derived PYQ
The important step in the process of decomposition in order is:
(1) Catabolism → Fragmentation → Leeching → Humification → Mineralization
(2) Catabolism → Fragmentation → Humification → Leeching → Mineralization
(3) Fragmentation → Humification → Catabolism → Leeching → Mineralization
(4) Fragmentation → Leeching → Catabolism → Humification → Mineralization
Answer ▽
(4) Fragmentation → Leeching → Catabolism → Humification → Mineralization
Decomposition is the process in which the complex organic matter is broken down into simpler organic substances and ultimately into inorganic compounds. Steps of Decomposition.
(i) Fragmentation : It is the process of breaking of the detritus into smaller particles by detritivores like earthworm.
(ii) Leaching : It is the process in which water soluble inorganic substances run down mto soil horizon and get precipitated as unavailable salts.
(iii) Catabolism: The enzymatic conversion of the detritus into simple organic compounds and then into inorganic compounds is called catabolism.
(iv) Humification : Humification during decomposition leads to the accumulation of a dark cloured amorphous substance called humus.
(v) Mineralisation : It is the process in which the humus is degraded by certain microbes and the inorganic nutrients are relased. The products of decomposition are simple organic moleculers and inorganic compounds.
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Question: From NCERT NEET Derived PYQ
Which of the following is false?
I. Quantity of biomass in a trophical level at a particular period is called standing crop.
II. The energy content in a trophic level is determined by considering a few individuals of a species in that trophic level.
III. The succession that occurs in nearly cooled lava is called primary succession.
IV. Rate of succession is faster in the secondary succession
V. Phytoplankton are the pioneers in aquatic succession
(1) Only II
(2) Only III
(3) Only V
(4) Only I and IV
Answer ▽
(1) Only II
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Question: From NCERT NEET Derived PYQ
The amount of biomass or organic matter produced per unit area over -a time period by plants during photosynthesis is called primary production, which is expressed as:
(1) g m−2
(2) kcal m−2
(3) (kcal m−2) yr−1
(4) Both (1) and (2)
Answer ▽
(4) Both (1) and (2)
Primary production is defined as the amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis. It is expressed in terms of weight (g−2) and energy (Kcal m−2 )
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Question: From NCERT NEET Derived PYQ
Primary production is defined as the amount of biomass or organic matter produced per unit area over a time period by plants during photosythesis. It is expressed in terms of . a. Weight (g^(-2)) " "
b. Weight (g^(-2) - yr^(-1))
c. Energy (kcal m^(-2)) " "
d. Energy (Kcal m^(-2) yr^(-1))
Answer ▽
C
Primary production is defined as the amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis. It is expressed in terms of weight and energy (Kcal )
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Question: From NCERT NEET Derived PYQ
During the stages of succession in a given ecosystem the following changes in characteristics may be observed:
| Characteristic | Stages in ecosystem development | |
| Early | Late | |
| A. Total matter | Low | High |
| B. Species diversity | Low | High |
| C. Size of organism | Small | Large |
| D. Productivity | Low | High |
| E. Food chains | Short | Long |
Which one of the characteristics, A, B, C, D or E is responsible for the apparent high degree of stability associated with a climax ecosystem?
(1) B
(2) D
(3) A
(4) E
Answer ▽
(1) B
Total organic matter keeps changing, and it is not responsible for stability. The size of the organism also does not determine the stability, as it can be both large and small during the early and late stages. Productivity is the generation of biomass, so it also keeps changing. The food chain is the transfer of energy from one species to another, and it can be either large or short. Species diversity is most important for the climax ecosystem. The relationship among the diversity of species and community sustainability highlights the necessity within biological communities to establish the greatest possible richness.
An ecological community where plant or animal species remain stable and live in harmony with each other and their climate. A climax society is the final stage of succession, remaining largely unchanged before destroyed by an event such as fire or human intervention
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Question: From NCERT NEET Derived PYQ
Some of the stages in the hydrarch are labelled as:
A. Marsh meadow stage
B. Reed swamp stage
C. Submerged plant stage
D. Phytoplankton stage
E. Submerged free floating plant stage
Identify the choice that represents the correct sequence of these stages:
(1) D, C, E, B and A
(2) C, E, A, B and D
(3) B, D, C, A and E
(4) D, E, C, B and A
Answer ▽
(1) D, C, E, B and A
The succession as we know will proceed from Hydric to mesic conditions. (Here, hydric means watery conditions and mesic means normal condition, that means from watery conditions to normal land conditions this succession works).
The pioneer species (first organisms to begin life) of the succession in water are small phytoplankton. This is then replaced by a submerged stage. Then, the next stage of the succession is the free floating stage in this as it is clear, the submerged plants are then replaced by free floating angiosperms in a span of time. In this stage, large and broad leaves of the floating plants will cover up the water body's surface to make up the conditions unfavorable for the growth of the species of the previous stage that is submerged plants and then in those unfavorable conditions they will gradually start disappearing.
Then, comes the new state known as Reed swamp stage. In this process, as we can guess from the previous stage the water body will now have emergent plants, these plants along with the mud will form the litter, and this litter will change the water body into a marshy land.
Now, water level will decrease and the new stage known as sedge meadow stage comes in the succession. In this stage, some of the plant species will begin to establish themselves and increase the mud litter to convert the situations to mesic. This will lead to complete loss of water body and establishment of the mesic (land like) conditions at that place.
further, in the Woodland stage, soil now remains drier for most of the year and becomes suitable for the wet Woodland and finally comes the climax stage, the climax of this succession will be either a forest or a grassland.
generally, climax is a forest. And with time, the water body is converted into land covered with the forest trees.
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Question: From NCERT NEET Derived PYQ
Which of the following is the functional unit of nature?
1. A plant
2. An animal
3. Ecosystem
4. Environment
Answer ▽
3. Ecosystem
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Question: From NCERT NEET Derived PYQ
Identify the odd one out?
1. Forest
2. Grassland
3. Desert
4. Wetland
Answer ▽
4. Wetland
Wetlands are areas where water covers the soil.
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Question: From NCERT NEET Derived PYQ
Primary production is expressed in terms of-
1. Grams
2. Grams/year
3. Gram/m2
4. Gram/m2/year
Answer ▽
3. Gram/m2
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Question: From NCERT NEET Derived PYQ
What do you mean by Productivity?
1. Rate of biomass production
2. Amount of biomass production
3. Biomass produced in an area
4. Biomass produced in a time period
Answer ▽
1. Rate of biomass production
Productivity: Rate of biomass production.
Gross primary production;primary producers create in a given length of time
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Question: From NCERT NEET Derived PYQ
Which of the following statement is incorrect?
(1). Gross primary productivity is the rate of production of organic matter during photosynthesis.
(2). Net primary productivity plus respiration losses, is the gross primary productivity.
(3). Gross primary productivity is defined for an ecosystem
(4). Gross primary productivity is the available biomass for the consumption to heterotrophs.
Answer ▽
(4). Gross primary productivity is the available biomass for the consumption to heterotrophs.
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Question: From NCERT NEET Derived PYQ
Secondary productivity is defined with respect to-
1. Producers
2. Consumers
3. Ratio of producers and consumers
4. Trophic level
Answer ▽
2. Consumers
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Question: From NCERT NEET Derived PYQ
What is the annual net primary productivity of the whole biosphere
1. 160 billion tons
2. 170 billion tons
3. 177 billion tons
4. 190 billion tons
Answer ▽
2. 170 billion tons
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Question: From NCERT NEET Derived PYQ
Which of the following contributes the maximum to the net primary productivity?
1. Ocean ecosystem
2. Land ecosystem
3. Pond ecosystem
4. Man-made ecosystem
Answer ▽
2. Land ecosystem
Tropical rainforests have the highest primary productivity on the terrestrial ecosystem.
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Question: From NCERT NEET Derived PYQ
Answer ▽
Correct option is B)
There are many ecosystems which have a very higher level of primary productivity. Coral reefs show the highest gross primary productivity in the aquatic ecosystem. There are the wide number of phytoplankton and aquatic phototrophs which contribute to the productivity of the ecosystem. Tropical rainforests have the highest primary productivity on the terrestrial ecosystem.
So, the correct answer is option B.
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Question: From NCERT NEET Derived PYQ
Which of the following statement is correct?
1. Dead plant and animals remains, including fecal matter, constitute detritus,
2. Detritus is the product of decomposition.
3. Breakdown of complex inorganic matter into organic substances like CO₂ and nutrients is called as decomposition.
4. Decomposition is a single step process.
Answer ▽
1. Dead plant and animals remains, including fecal matter, constitute detritus,
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Question: From NCERT NEET Derived PYQ
What does the process of leaching refers to-
1. Accumulation of a dark coloured amorphous substance
2. Organic solvents reabsorbed by the plants
3. Inorganic solvents get precipitated out of the soil
4. Water soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts.
Answer ▽
4. Water soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts.
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Question: From NCERT NEET Derived PYQ
Which of the following is the substrate in the process of mineralisation?
1. Detritus
2. Humus
3. Organic matter
4. None of the above
Answer ▽
2. Humus
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Question: From NCERT NEET Derived PYQ
Which of the following does not affect rate of decomposition?
1. Substrate composition
2. Soil moisture
3. Temperature of soil
4.CO₂
Answer ▽
4.CO₂
A multitude of factors can affect the decomposition process, increasing or decreasing its rate. Some of the most frequently observed variables are temperature, moisture, insect activity, and sun or shade exposure.
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Question: From NCERT NEET Derived PYQ
Decomposition would be fast if the detritus contains-
1. Cellulose
2. Lignin and chitin
3. Nitrogen and water soluble sugars
4. Cellulose and pectin
Answer ▽
3. Nitrogen and water soluble sugars
Decomposition is the process of breaking down organic matter into simple inorganic matter. Under same environmental conditions, the rate of decomposition various due to change in composition of detritus. If detritus is rich in lignin and chitin, the decomposition rate is slow. If detritus is rich in nitrogen, the decomposition rate is relatively high.
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Question: From NCERT NEET Derived PYQ
Answer ▽
Correct option is D)
Decomposition is the process of breaking down organic matter into simple inorganic matter. Under same environmental conditions, the rate of decomposition various due to change in composition of detritus. If detritus is rich in lignin and chitin, the decomposition rate is slow. If detritus is rich in nitrogen, the decomposition rate is relatively high.
Thus, the correct answer is 'Lignin and chitin.
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Question: From NCERT NEET Derived PYQ
What is the source of energy for all ecosystems on Earth?
1. Sun
2. Hydrothermal vents
3. Lava
4. Both ‘1’ and ‘2’
Answer ▽
4. Both ‘1’ and ‘2’
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