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Ecosystem

87 Questions Start NEET Test
All Exams NEET AIIMS
2014 Q51 NEET MCQ
10 Mar 2026
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 → mice → snake → peacock
A.
0.0002 J
B.
0.002 J
C.
0.2 J
D.
0.02 J
2013 Q52 NEET MCQ
10 Mar 2026
Which two distinct microbial processes are responsible for the release of fixed nitrogen as dinitrogen gas (N2) to the atmosphere ?
A.
Anaerobic ammonium oxidation, and denitrificatrion
B.
Aerobic nitrate oxidation, and nitrite reduction
C.
Enteric fermentation in cattle, and nitrogen fixation by Rhizobium in root nodules of legumes
D.
Decomposition of organic nitrogen, and conversion of dinitrogen to ammonium compounds
2013 Q53 NEET MCQ
10 Mar 2026
Which one of the following is a primary consumer in maize field ecosystem ?
A.
Phytoplankton
B.
Lion
C.
Grasshopper
D.
Wolf
2013 Q54 NEET MCQ
10 Mar 2026
When man eats fish which feeds on zooplankton which have eaten small plants, the producer in the chain is :
A.
Zooplankton
B.
Fish
C.
Small plants
D.
Man
2013 Q55 NEET MCQ
10 Mar 2026
Which one of the following processes during decomposition is correctly described ?
A.
Catabolism – Last step in the decomposition under fully anaerobic condition
B.
Leaching – Water soluble inorganic nutrients rise to the top layers of soil
C.
Fragmentation –Carried out by organisms such as earthworm
D.
Humification – Leads to the accumulation of a dark coloured substance humus which undergoes microbial action at a very fast rate
2013 Q56 NEET MCQ
10 Mar 2026
Natural reservoir of phosphorus is :
A.
Fossils
B.
Rock
C.
Sea water
D.
Animal bones
2013 Q57 NEET MCQ
10 Mar 2026
Secondary productivity is rate of formation of new organic matter by :
A.
Parasite
B.
Decomposer
C.
Producer
D.
Consumers
2012 Q58 NEET MCQ
10 Mar 2026
The rate of formation of new organic matter by rabbit in a grassland, is called :
A.
Net productivity
B.
Gross primary productivity
C.
Secondary productivity
D.
Net primary productivity
2012 Q59 NEET MCQ
10 Mar 2026
The second stage of hydrosere is occupied by plants like
A.
Vallisneria
B.
Typha
C.
Azolla
D.
Salix
2012 Q60 NEET MCQ
10 Mar 2026
Identify the likely organisms (a), (b), (c) and (d) in the food web shown below : AIPMT 2012 Mains Biology - Ecosystem Question 57 English
A.
(a) $ \to $ deer , (b) $ \to $ rabbit , (c) $ \to $ frog, (d) $ \to $ rat
B.
(a) $ \to $ squirrel , (b) $ \to $ cat, (c) $ \to $ rat , (d) $ \to $ pigeon
C.
(a) $ \to $ dog, (b) $ \to $ squirrel , (c) $ \to $ bat , (d) $ \to $ deer
D.
(a) $ \to $ rat , (b) $ \to $ dog , (c) $ \to $ tortoise, (d) $ \to $ crow
2012 Q61 NEET MCQ
10 Mar 2026
The upright pyramid of number is absent in
A.
Pond
B.
Grassland
C.
Lake
D.
Forest
2012 Q62 NEET MCQ
10 Mar 2026
Identify the possible link "A" in the following food chain :
Plant → insect → frog →"A"→ Eagle
A.
Wolf
B.
Rabbit
C.
Cobra
D.
Parrot
2012 Q63 NEET MCQ
10 Mar 2026
Which one of the following is not a functional unit of an ecosystem?
A.
Energy flow
B.
Decomposition
C.
Productivity
D.
Stratification
2012 Q64 NEET MCQ
10 Mar 2026
Giiven below is an imaginary pyramid of numbers. What could be one of the possibilities about certain organisms at some of the different levels ? AIPMT 2012 Prelims Biology - Ecosystem Question 62 English
A.
Level PC is "rats" and level SC is "cats"
B.
Level PP is "phytoplanktons" in sea and "Whale" on top level TC
C.
Level one PP is "pipal trees" and the level SC is "sheep"
D.
Level PC is "insects" and level SC is "small insectivorous birds"
2012 Q65 NEET MCQ
10 Mar 2026
Which one of the following is not a gaseous biogeochemical cycle in ecosystem ?
A.
Sulphur Cycle
B.
Nitrogen Cycle
C.
Phosphorus Cycle
D.
Carbon Cycle
2011 Q66 NEET MCQ
10 Mar 2026
Which one of the following animals may occupy more than one trophic levels in the same ecosystem at the same time ?
A.
Lion
B.
Frog
C.
Goat
D.
Sparrow
2011 Q67 NEET MCQ
10 Mar 2026
Both, hydrarch and xerarch successions lead to :
A.
Xeric conditions
B.
Excessive wet conditions
C.
Highly dry conditions
D.
Medium water conditions
2011 Q68 NEET MCQ
10 Mar 2026
The breakdown of detritus into smaller particles by earthworm is a process called
A.
Fragmentation
B.
Catabolism
C.
Mineralisation
D.
Humification
2011 Q69 NEET MCQ
10 Mar 2026
Of the total incident solar radiation the proportion of PAR is
A.
About 60%
B.
More than 80%
C.
Less than 50%
D.
About 70%
2011 Q70 NEET MCQ
10 Mar 2026
Which one of the following statements for pyramid of energy is incorrect, whereas the remaining three are correct?
A.
It shows energy content of different trophic level organisms
B.
It is upright in shape
C.
It is inverted in shape
D.
Its base is broad
2011 Q71 NEET MCQ
10 Mar 2026
Mass of living matter at a trophic level in an area at any time is called :
A.
Humus
B.
Detritus
C.
Standing state
D.
Standing crop
2011 Q72 NEET MCQ
10 Mar 2026
Which one of the following statements is correct for secondary succession?
A.
It follows primary succession
B.
It occurs on deforested site
C.
It is similar to primary succession except that it has a relatively fast pace.
D.
It begins on a bare rock.
2010 Q73 NEET MCQ
10 Mar 2026
Which of the following representations shows the pyramid of numbers in a forest ecosystem ? AIPMT 2010 Mains Biology - Ecosystem Question 48 English
1.
B
2.
A
3.
D
4.
C
2010 Q74 NEET MCQ
10 Mar 2026
The biomass available for consumption by the herbivores and the decomposers is called –
A.
Standing crop
B.
Net primary productivity
C.
Gross primary productivity
D.
Secondary productivity
2009 Q75 NEET MCQ
10 Mar 2026
Which one of the following types organisms occupy more than one trophic level in a pond ecosystem ?
A.
Phytoplankton
B.
Zooplankton
C.
Frog
D.
Fish
2009 Q76 NEET MCQ
10 Mar 2026
The correct sequence of plants in hydrosere is :
A.
Volvox → Hydrilla → Pistia → Scirpus → Lantana → Oak
B.
Pistia → Volvox → Scirpus → Hydrilla → Oak → Lantana
C.
Oak → Lantana → Volvox → Hydrilla → Pistia → Scirpus
D.
Oak → Lantana → Scirpus → Pistia → Hydrilla → Volvox
2008 Q77 NEET MCQ
10 Mar 2026
Consider the following statements concerning food chains:
(i) Removal of 80% tigers from an area resulted in greatly increased growth of vegetation
(ii) Removal of most of the carnivores resulted in an increased population of deers
(iii) The length of food chains is generally limited to 3-4 trophic levels due to energy loss
(iv) The length of food chains may vary from 2 to 8 trophic levels
Which of two of the above statements are correct ?
A.
(iii), (iv)
B.
(ii), (iii)
C.
(i), (iv)
D.
(i), (ii)
2008 Q78 NEET MCQ
10 Mar 2026
The slow rate of decomposition of fallen logs in nature is due to their:
A.
low moisture content
B.
poor nitrogen content
C.
anaerobic environment around them
D.
low cellulose content
2008 Q79 NEET MCQ
10 Mar 2026
About 70% of total global carbon is found in:
A.
Grasslands
B.
Agroecosystems
C.
Oceans
D.
Forests
2007 Q80 NEET MCQ
10 Mar 2026
Which one of the following ecosystem types has the highest annual net primary productivity ?
A.
Temperate evergreen forest
B.
Temperate deciduous forest
C.
Tropical rain forest
D.
Tropical deciduous forest
2006 Q81 NEET MCQ
10 Mar 2026
Which one of the following is not used for construction of ecological pyramids ?
A.
Rate of energy flow
B.
Dry weight
C.
Fresh weight
D.
Number of individuals
2004 Q82 NEET MCQ
10 Mar 2026
An ecosystem which can be easily damaged but can recover after some time if damaging effect stops will be having -
A.
High stability and high resilience
B.
Low stability and high resilience
C.
High stability and low resilience
D.
Low stability and low resilience
2004 Q83 NEET MCQ
10 Mar 2026
Which of the following is expected to have the highest value (gm/m2/yr) in a grassland ecosystem ?
A.
Net production (NP)
B.
Secondary production
C.
Tertiary production
D.
Gross production (GP)
2003 Q84 NEET MCQ
10 Mar 2026
Which of the following plants are used as green manure in crop fields and in sandy soils ?
A.
Calotropis procera and Phyllanthus niruri
B.
Dichanthium annulatum and Azolla nilotica
C.
Saccharum munja and Lantana camara
D.
Crotalaria juncea and Alhagi camelorum
2002 Q85 NEET MCQ
10 Mar 2026
Bamboo plant is growing in a far forest then what will be the trophic level of it ?
A.
Second trophic level (T2)
B.
First trophic level (T1)
C.
Fourth trophic level (T4)
D.
Third trophic level (T3)
2001 Q86 NEET MCQ
10 Mar 2026
Plant Decomposers are : -
A.
Protista and Animalia
B.
Anibalia and Mogna
C.
Monera and fungi
D.
Fungi and plants
2000 Q87 NEET MCQ
10 Mar 2026
Which is the reason for highest biomass in aquatic ecosystem ?
A.
Benthonic and brown algae
B.
Nano plankton, blue green algae, green algae
C.
Diatoms
D.
Sea grass, and slime molds