Objective Biology for NEET

Rajiv Vijay

Chapter 14

Ecosystem - all with Video Answers

Educators

+ 3 more educators

Chapter Questions

Problem 1

The following are examples of terrestrial ecosystem except
(a) Forest
(b) Wetland
(c) Grassland
(d) Desert

FZ

Fathima Zahra

Numerade Educator

Problem 2

Which of these are examples of aquatic ecosystem?
(a) Pond
(b) River
(c) Estuary
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 3

Which of these are examples of man-made ecosystem?
(a) Crop field
(b) Aquarium
(c) Wetland
(d) Both (a) and (b)

FZ

Fathima Zahra

Numerade Educator

Problem 4

Find out the incorrect statement.
(a) Biosphere is a global ecosystem.
(b) Transfer of energy in ecosystem explains in terms of food web and nutrient cycle.
(c) Pond, lake and wetland are aquatic ecosystems.
(d) Ecosystem is structural not functional unit of ecosystem.

FZ

Fathima Zahra

Numerade Educator

Problem 5

Which of the following occupy top vertical strata of forest ecosystem?
(a) Shrubs
(b) Herbs and grasses
(c) Tree
(d) Phytoplankton

FZ

Fathima Zahra

Numerade Educator

Problem 6

Pond is a
(a) Shallow fresh water body
(b) Deep fresh water body
(c) Shallow marine water body
(d) Deep marine water body

FZ

Fathima Zahra

Numerade Educator

Problem 7

The functional aspect of ecosystem can be explained in terms of
(a) Productivity
(b) Decomposition and energy flow
(c) Nutrient cycle
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 8

At the bottom of ponds the decomposers found are
(a) Fungi
(b) Bacteria
(c) Flagellates
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 9

Which of the following have only unidirectional flow?
(a) Carbon
(b) Nitrogen
(c) Energy
(d) Sulphur

Hast Aggarwal

Numerade Educator

Problem 10

The amount of biomass or organic matter produced per unit area over a period of time by plants during photosynthesis is known as
(a) Primary production
(b) Secondary production
(c) Net primary production
(d) Net secondary production

FZ

Fathima Zahra

Numerade Educator

Problem 11

The unit of primary production is
(a) $\mathrm{g} / \mathrm{m}^{2}$
(b) $\mathrm{kcal} / \mathrm{m}^{2}$
(c) Both (a) and (b)
(d) None of these

FZ

Fathima Zahra

Numerade Educator

Problem 12

NPP is equal to
(a) GPP + R
(b) GPP - R
(c) GPP $\times \mathrm{R}$
(d) GPP \div R

FZ

Fathima Zahra

Numerade Educator

Problem 13

Secondary productivity means
(a) Rate of formation of organic matter by producer.
(b) Rate of formation of new organic matter by consumers.
(c) Rate of formation of inorganic matter by producer.
(d) Rate of formation of inorganic matter by consumers.

FZ

Fathima Zahra

Numerade Educator

Problem 14

Primary productivity depends on which of the following factors?
(a) Environmental factor
(b) Photosynthetic capacity of plant
(c) Availability of nutrients
(d) All the above

FZ

Fathima Zahra

Numerade Educator

Problem 15

GPP means
(a) Gross Public Partnership
(b) Gross Primary Production
(c) Gross Producer Production
(d) Gross Plant Production

FZ

Fathima Zahra

Numerade Educator

Problem 16

The unit of productivity is
(a) $\mathrm{gm}^{-2} \mathrm{yr}^{-1}$
(b) $\mathrm{Kcal} / \mathrm{m}^{2} /$ year
(c) Both (a) and (b)
(d) None

Hast Aggarwal

Numerade Educator

Problem 17

NPP means
(a) Available biomass for the consumption of heterotrophs
(b) Biomass produced by producers
(c) Gross primary product of respiratory losses
(d) All of the above

Hast Aggarwal

Numerade Educator

Problem 18

The annual net primary productivity of the whole biosphere is how much billion tons (dry weight) of organic matter?
(a) 120
(b) 170
(c) 210
(d) 150

FZ

Fathima Zahra

Numerade Educator

Problem 19

Oceans occupy _________ % of the surface of earth but productivity of ocean are _________ billion tons.
(a) 70,45
(b) 60,55
(c) 70,55
(d) 60,65

Hast Aggarwal

Numerade Educator

Problem 20

The productivity of ocean is less because
(a) It occupies 70 per cent of earth's surface.
(b) Light is a major limiting factor which decreases with increase in water depth.
(c) It contains algae as a chief producer.
(d) All the above

Hast Aggarwal

Numerade Educator

Problem 21

What is the percentage of primary productivity of oceans?
(a) $50 \%$
(b) $90 \%$
(c) $32 \%$
(d) $70 \%$

FZ

Fathima Zahra

Numerade Educator

Problem 22

Earthworms help in
(a) Breakdown of complex organic matter
(b) Loosening of soil
(c) Both (a) and (b)
(d) None of these

FZ

Fathima Zahra

Numerade Educator

Problem 23

Detritus contain
(a) Dead plant remains (leaves, bark and flower)
(b) Dead animal remains
(c) Fecal matter
(d) All the above
mposition

FZ

Fathima Zahra

Numerade Educator

Problem 24

The important steps in the process of decomposition are
(a) Fragmentation
(b) Leaching
(c) Catabolism
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 25

Match the columns:
$$
\begin{array}{ll}
\hline \text { Column-I } & \text { Column-II } \\
\hline \text { 1. Fragmentation } & \text { A. Break down of detritus into smaller particles } \\
\text { 2. Leaching } & \text { B. Precipitation of water soluble nutrients as unavailable salt } \\
\text { 3. Catabolism } & \text { C. Degradation of detritus by bacterial and fungal enzymes } \\
\hline
\end{array}
$$
(a) $1-\mathrm{A}, 2-\mathrm{B}, 3-\mathrm{C}$
(b) $1-\mathrm{B}, 2-\mathrm{C}, 3-\mathrm{A}$
(c) $1-\mathrm{C}, 2-\mathrm{B}, 3-\mathrm{A}$
(d) $1-\mathrm{C}, 2-\mathrm{A}, 3-\mathrm{B}$

FZ

Fathima Zahra

Numerade Educator

Problem 26

Which of these are true about humus?
(a) Dark coloured amorphous substance
(b) Colloidal in nature
(c) Reservoir of nutrient
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 27

Humus is degraded by some microbes and release of inorganic nutrients occur by the process known as
(a) Fragmentation
(b) Leaching
(c) Humidification
(d) Mineralization

Hunza Gilgit

Numerade Educator

Problem 28

Find out the total number of incorrect statements from the following:
(A) Decomposition is largely an anaerobic process.
(B) Fragmentation, leaching and catabolism occur simultaneously on detritus.
(C) Vertical distribution of different species occupying different level is called stratification.
(D) Pond is a deep water body.
(E) The rate of decomposition is controlled by chemical composition of detritus and climatic factors.
(a) 1
(b) 2
(c) 3
(d) 4

Sirisa Reddy

Numerade Educator

Problem 29

Decomposition is favoured by
(a) Warm and moist environment.
(b) Rich amount of nitrogen and water soluble substance like sugar in detritus.
(c) Aerobic environment
(d) All the above

FZ

Fathima Zahra

Numerade Educator

Problem 30

The rate of decomposition process is decreased by
(a) Aerobic environment
(b) Rich amount of lignin and chitin in detritus
(c) Worm and moist environment
(d) All the above

FZ

Fathima Zahra

Numerade Educator

Problem 31

What is the main source of energy for all ecosystems on earth?
(a) Sun
(b) Volcano
(c) Deep sea hydro-thermal system
(d) Moon

FZ

Fathima Zahra

Numerade Educator

Problem 32

PAR (Photosynthetically active radiation) from incident solar radiation is
(a) $50 \%$
(b) $30 \%$
(c) $70 \%$
(d) $20 \%$

FZ

Fathima Zahra

Numerade Educator

Problem 33

Plant capture how much of PAR?
(a) 2-10\%
(b) $10-20 \%$
(c) $50 \%$
(d) $30 \%$

FZ

Fathima Zahra

Numerade Educator

Problem 34

Which law is obeyed during energy flow in an ecosystem?
(a) First law of thermodynamics
(b) Second law of thermodynamics
(c) Third law of thermodynamics
(d) Both (a) and (b)

Hunza Gilgit

Numerade Educator

Problem 35

In a terrestrial ecosystem the major producers are
(A) Herbs
(B) Woody plant
(C) Shrubs
(a) $\mathrm{A}$ and $\mathrm{B}$ only
(b) $\mathrm{A}$ and $\mathrm{C}$ only
(c) A, B and C
(d) B only

Sirisa Reddy

Numerade Educator

Problem 36

Primary producers in aquatic ecosystem are
(a) Phytoplankton
(b) Algae
(c) Higher plant
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 37

Which of these is a primary consumer?
(a) Grass
(b) Goat
(c) Man
(d) Tiger

FZ

Fathima Zahra

Numerade Educator

Problem 38

Which of these is a common herbivores in aquatic ecosystem?
(a) Insect
(b) Birds
(c) Mammals
(d) Mollusc

FZ

Fathima Zahra

Numerade Educator

Problem 39

Which of the following represent simple GFC (Grazing Food Chain)?
(a) Grass $\rightarrow$ Goat $\rightarrow$ Man
(b) Goat $\rightarrow$ Grass $\rightarrow$ Man
(c) Detritus $\rightarrow$ Fungi $\rightarrow$ Man
(d) Fungi $\rightarrow$ Detritus $\rightarrow$ Grass

FZ

Fathima Zahra

Numerade Educator

Problem 40

DFC (Detritus Food Chain) begins with
(a) Dead organic matter
(b) Fungi
(c) Bacteria
(d) Plant

FZ

Fathima Zahra

Numerade Educator

Problem 41

The main decomposers are
(a) Bacteria and fungus
(b) Earthworm
(c) Flagellated protozoans
(d) Flagellated diatoms

FZ

Fathima Zahra

Numerade Educator

Problem 42

Decomposers meet their energy and nutrient requirements by
(a) Phytoplanktons
(b) Zooplanktons
(c) Detritus
(d) Bacteria

FZ

Fathima Zahra

Numerade Educator

Problem 43

GFC is a major conduit for energy flow in
(a) Terrestrial ecosystem
(b) Aquatic ecosystem
(c) Both (a) and (b)
(d) None of these

FZ

Fathima Zahra

Numerade Educator

Problem 44

Decomposers shows
(a) Intracellular digestion
(b) Extracellular digestion
(c) Both intra and extracellular digestion
(d) No digestion at all

FZ

Fathima Zahra

Numerade Educator

Problem 45

Find the incorrect statement.
(a) In terrestrial ecosystem larger fraction of energy flow occurs through DFC.
(b) In aquatic ecosystem a major conduit for energy flow is GFC.
(c) Detritus food chain is not at all connected with grazing food chain at any level.
(d) Natural interconnection of food chain makes it a food web.

FZ

Fathima Zahra

Numerade Educator

Problem 46

Based on the source of their nutrient or food, organisms occupy a specific place in the food chain that is known as their
(a) Hierarchy position
(b) Class
(c) Order
(d) Trophic level

FZ

Fathima Zahra

Numerade Educator

Problem 47

Herbivoures are
(a) Producers
(b) Primary consumers
(c) Secondary consumer
(d) Tertiary consumers

FZ

Fathima Zahra

Numerade Educator

Problem 48

Plants are
(a) Producers
(b) Primary consumers
(c) Secondary consumers
(d) Tertiary consumers

FZ

Fathima Zahra

Numerade Educator

Problem 49

Each tropic level has a certain mass of living material at a particular time called
(a) Standing state
(b) Stranding crop
(c) Ecological pyramid
(d) GPP

FZ

Fathima Zahra

Numerade Educator

Problem 50

Stranding crop is measured in terms of
(a) Biomass/unit area
(b) Number of organism/unit area
(c) Both (a) or (b)
(d) None of these

FZ

Fathima Zahra

Numerade Educator

Problem 51

Measurement of biomass is generally done in terms of
(a) Fresh weight
(b) Dry weight
(c) Ash
(d) Numbers of organisms

FZ

Fathima Zahra

Numerade Educator

Problem 52

What does A represent in the diagram?
$\begin{array}{cccc}\begin{array}{c}\text { First trophic } \\ \text { level producers } \\ \text { (Plants) }\end{array} & \begin{array}{c}\text { Second trophic level } \\ \text { primary consumers }\end{array} & \begin{array}{c}\text { Third trophic } \\ \text { (Herbivores) }\end{array} & \begin{array}{c}\text { Fourth trophic } \\ \text { consumers } \\ \text { (Carnivores) }\end{array} & \begin{array}{c}\text { level tertiary } \\ \text { consumers } \\ \text { (top Carnivores) }\end{array}\end{array}$
(a) Food
(b) Heat
(c) Water
(d) $\mathrm{CO}_{2}$

Sirisa Reddy

Numerade Educator

Problem 53

Transfer of energy in tropic level follows
(a) $20 \%$ law
(b) $10 \%$ law
(c) $5 \%$ law
(d) $15 \%$ law

FZ

Fathima Zahra

Numerade Educator

Problem 54

A graphical representation known as _________ is required to express food or energy relationship between organisms at different trophic levels.
(a) Ecological pyramid
(b) Standing state
(c) Ecological quadrilateral
(d) Standing crop

FZ

Fathima Zahra

Numerade Educator

Problem 55

Ecological pyramids are based on
(a) Food chain
(b) Food web
(c) Energy flow
(d) All of these

Hunza Gilgit

Numerade Educator

Problem 56

How many ecological pyramids are usually studied?
(a) 1
(b) 2
(c) 3
(d) 4

FZ

Fathima Zahra

Numerade Educator

Problem 57

Ecological pyramids are
(a) Pyramids of number
(b) Pyramids of biomass
(c) Pyramids of energy
(d) All the above

FZ

Fathima Zahra

Numerade Educator

Problem 58

Which of the following pyramid is always upright?
(a) Energy
(b) Biomass
(c) Number
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 59

How much energy of sunlight is converted by primary producers into NPP in the above energy pyramid?

Rakesh Singhi

Numerade Educator

Problem 60

How many top-carnivores are supported in an above grassland ecosystem based on production of nearly 6 million plants?
(a) 3
(b) 6
(c) 9
(d) 12

Hunza Gilgit

Numerade Educator

Problem 61

An inverted pyramid of biomass is seen in
(a) Forest ecosystem
(b) Grassland ecosystem
(c) Aquatic ecosystem
(d) Desert

FZ

Fathima Zahra

Numerade Educator

Problem 62

Find out the correct statement:
(a) Trophic level represents a functional level, not a species as such.
(b) A given species never occupies more than one trophic level in the same ecosystem at the same time.
(c) In most of the ecosystems, producers are less in number and biomass than the herbivores.
(d) Pyramid of energy can never be upright.

Hunza Gilgit

Numerade Educator

Problem 63

Which of the following are limitations of ecological pyramids?
(a) It does not take into account the same species belonging to two or more trophic levels.
(b) It assumes a simple food chain that almost does not exist in nature.
(c) Saprophytes are not given at any place.
(d) All the above

FZ

Fathima Zahra

Numerade Educator

Problem 64

Which of the following may occupy more than one trophic level in the same ecosystem at the same time?
(a) Lion
(b) Sparrow
(c) Snake
(d) Frog

Hunza Gilgit

Numerade Educator

Problem 65

Which of these are true about sparrows?
(a) When it eats seeds and peas, it is a primary consumer.
(b) When it eats insects and worms, it is a secondary consumer.
(c) It may occupy more than one trophic level in same ecosystem at the same time.
(d) All the above

FZ

Fathima Zahra

Numerade Educator

Problem 66

Which of the following organisms have no space in ecological pyramid although they play vital role in the ecosystem?
(a) Birds
(b) Snake
(c) Bacteria and fungi
(d) Frog

FZ

Fathima Zahra

Numerade Educator

Problem 67

Orderly and sequential changes in communities, parallel with the changes in the physical environment is known as
(a) Ecological succession
(b) Extinction
(c) Divergent evolution
(d) Convergent evolution

FZ

Fathima Zahra

Numerade Educator

Problem 68

The entire sequence of communities that successively change in a given area are called
(a) Extinction
(b) Evolution
(c) Succession
(d) Sere

FZ

Fathima Zahra

Numerade Educator

Problem 69

In the successive seral stages
(a) There is change in diversity of species of organisms.
(b) Increase in number of species occurs.
(c) Increase in biomass occurs.
(d) All the above

FZ

Fathima Zahra

Numerade Educator

Problem 70

If succession occurs on bare rock, it is known as
(a) Primary succession
(b) Secondary succession
(c) Tertiary succession
(d) Quaternary succession

FZ

Fathima Zahra

Numerade Educator

Problem 71

Primary succession occurs on/in
(a) Bare rocks
(b) Newly cooled lava
(c) Newly created pond
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 72

Secondary succession occurs in:
(a) Flooded land
(b) Burned forest
(c) Abandoned farm land
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 73

How is primary succession different from secondary succession?
(a) There is change in type of animals and plants during primary succession only.
(b) Anthropogenic disturbance can change seral stages in primary succession only.
(c) Primary succession occurs at slower rate.
(d) All the above

FZ

Fathima Zahra

Numerade Educator

Problem 74

What happened during succession?
(a) Extinction of some species
(b) Increase in number of some species
(c) Change in type of decomposer species
(d) All of these

Mishal Gul

Numerade Educator

Problem 75

In secondary succession the species that invades an area depend on
(a) Soil condition
(b) Water availability
(c) Seed or propagules present
(d) All of these

Mishal Gul

Numerade Educator

Problem 76

In which succession is the climax reached faster?
(a) Succession on bare rock
(b) Succession on burned forest
(c) Succession on newly cooled lava
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 77

Which is correct order of seral stages in hydrarch?
(a) Phytoplankton-submerged plant-submerged free floating plant stage-reed swamp stagemarsh-meadow stage-scrub stages-forest
(b) Scrub stages-forest-reed swamp stage-marsh-meadow stage-submerged free floating plant stage-submerged plant-phytoplankton
(c) Submerged plant-marsh-meadow stage-scrub stages-forest-phytoplankton-submerged free floating plant stage-reed swamp stage
(d) Phytoplankton-reed swamp stage-scrub stages-forest-submerged plant-submerged free floating plant stage-marsh-meadow stage

Mishal Gul

Numerade Educator

Problem 78

Which is a pioneer species in primary succession on rocks?
(a) Algae
(b) Lichens
(c) Bryophyte
(d) Pteridophyte

FZ

Fathima Zahra

Numerade Educator

Problem 79

A. Lichens are pioneer species on rocks.
R. They secrete acids to dissolve rocks, it helps in weathering and soil formation.
(a) $\mathrm{A}$ and $\mathrm{R}$ are both correct
(b) $\mathrm{A}$ and $\mathrm{R}$ are both incorrect
(c) A is correct but $\mathrm{R}$ is incorrect
(d) $\mathrm{R}$ is correct but $\mathrm{A}$ is incorrect

FZ

Fathima Zahra

Numerade Educator

Problem 80

Find out the total number of true statements from the following.
(A) Primary succession is a very slow process, taking thousands of years for the climax to be reached.
(B) All succession whether taking place in water or land, proceeds to a similar climax community, the mesic.
(C) As succession proceeds, the number and types of animals and decomposers also change.
(D) Saprophytes are not given at any place in the ecological pyramids even though they play a vital role in the ecosystem.
(a) 1
(b) 2
(c) 3
(d) 4

FZ

Fathima Zahra

Numerade Educator

Problem 81

The amount of nutrients such as carbon, nitrogen, phosphorus, calcium, etc., present in the soil at any given time is referred to as
(a) Standing state
(b) Standing crop
(c) Hydrarch
(d) Xerarch

FZ

Fathima Zahra

Numerade Educator

Problem 82

Nutrient cycling is known as
(a) Biogeochemical cycle
(b) Calvin cycle
(c) Hatch-slack pathway
(d) Krebs cycle

FZ

Fathima Zahra

Numerade Educator

Problem 83

Standing state
(a) Vary according to the type of ecosystem
(b) Vary on seasonal basis
(c) Both (a) and (b)
(d) None of these

FZ

Fathima Zahra

Numerade Educator

Problem 84

How many types of nutrient cycles are there?
(a) 1
(b) 2
(c) 3
(d) 4

FZ

Fathima Zahra

Numerade Educator

Problem 85

The following elements shows gaseous type of nutrient cycles except
(a) Carbon
(b) Nitrogen
(c) Oxygen
(d) Phosphorus

FZ

Fathima Zahra

Numerade Educator

Problem 86

Which of the following factors regulate the release of nutrients into the atmosphere?
(a) Soil and moisture
(b) $\mathrm{pH}$
(c) Temperature
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 87

Which nutrients flows through the sedimentary cycle?
(a) Sulphur
(b) Phosphorus
(c) Both (a) and (b)
(d) Carbon

FZ

Fathima Zahra

Numerade Educator

Problem 88

What percentage of the dry weight of an organism does carbon constitute?
(a) $60 \%$
(b) $90 \%$
(c) $49 \%$
(d) $35 \%$

FZ

Fathima Zahra

Numerade Educator

Problem 89

What percentage of global carbon does the atmosphere contain?
(a) $48 \%$
(b) $71 \%$
(c) $1 \%$
(d) $10 \%$

FZ

Fathima Zahra

Numerade Educator

Problem 90

How much carbon is fixed approximately in biosphere annually through the process of photosynthesis?
(a) $4 \times 10^{13} \mathrm{~kg}$
(b) $4 \times 10^{10} \mathrm{~kg}$
(c) $4 \times 10^{8} \mathrm{~kg}$
(d) $4 \times 10^{20} \mathrm{~kg}$

FZ

Fathima Zahra

Numerade Educator

Problem 91

Which of the following majorly regulates the amount of $\mathrm{CO}_{2}$ in the atmosphere?
(a) Respiratory activities of the producers and consumers
(b) Decomposers
(c) Burning of fossil fuel
(d) Oceanic reservoir

Gaurav Priyank

Numerade Educator

Problem 92

Human activities mainly influence the
(a) Carbon cycle
(b) Nitrogen cycle
(c) Phosphorus cycle
(d) Sulphur cycle

FZ

Fathima Zahra

Numerade Educator

Problem 93

Phosphorus is a major constituent of
(a) Biological membrane
(b) Nucleic acids
(c) Cellular energy transfer system
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 94

Which of the following are the differences between carbon and phosphorus cycle?
(a) Carbon cycle is sedimentary whereas phosphorus cycle is gaseous.
(b) Carbon cycle is not significantly affected by human activities whereas phosphorus is significantly affected.
(c) Carbon has respiratory release but not phosphorus.
(d) All the above

Colton Wang

Numerade Educator

Problem 95

A chart is given to represent the phosphorus cycle in a terrestrial ecosystem. Find out what $\mathrm{A}$, B, C and D represents in the flow chart.
(a) A-Producers, B-Detritus, C-Soil solution, D- Litter fall
(b) A-Litter fall, B - Soil solution, C-Detritus, D-Producers
(c) A-Detritus, B - Producers, C-Litter fall, D-Soil solution
(d) A-Soil solution, B-Litter fall, C-Litter fall, D-Detritus

Khalida Dawar

Numerade Educator

Problem 96

What price tag did Robert Costanza put for fundamental ecosystem services?
(a) 33 trillion US $\$$
(b) 22 trillion US $\$$
(c) 11 trillion US $\$$
(d) 44 trillion US $\$$

Nick Johnson

Numerade Educator

Problem 97

Global GNP is about:
(a) 33 trillion US $\$$
(b) 18 trillion US $\$$
(c) 12 trillion US $\$$
(d) 22 trillion US $\$$

Carson Merrill

Numerade Educator

Problem 98

Out of the total cost of various ecosystem services, the soil account for _________ %, recreation and nutrient cycling are less than _________ % and climate regulation and habitat for wildlife is about _________ % each.
(a) $50,6,10$
(b) $50,10,6$
(c) $50,30,20$
(d) $20,30,50$

Morgan Thompson

Morgan Thompson

Numerade Educator

Problem 99

Which one of the following has the largest population in a food chain?
(a) Producers
(b) Primary consumers
(c) Secondary consumers
(d) Decomposers

Qudsiya Anis

Numerade Educator

Problem 100

Which of the following are ecosystem services?
(a) Purification of air and water by forest
(b) Crop pollination
(c) Nutrient cycling
(d) All of these

Kayla Scholl

Numerade Educator

Problem 101

Which of the following are the two main structural features of an ecosystem?
(A) Species composition
(B) Energy flow
(C) Decomposition
(D) Stratification

FZ

Fathima Zahra

Numerade Educator

Problem 102

Which of the following are the reservoir of gaseous cycle?
(a) Atmosphere
(b) Earth crust
(c) Hydrosphere
(d) Both (a) and (c)

Morgan Thompson

Morgan Thompson

Numerade Educator

Problem 103

Which of the following nutrient cycle is the most complex?
(a) Nitrogen cycle
(b) Phosphorous cycle
(c) Carbon cycle
(d) Oxygen cycle

Billy Huggins

Numerade Educator

Problem 104

Biotic community is
(a) Static
(b) Dynamic
(c) Group of population of same species in a given area
(d) All the above

Amrita Narasimhan

Amrita Narasimhan

Numerade Educator

Problem 105

The stage of succession represented in the diagram is
(a) Read swamp stage
(b) Scrub stage
(c) Marsh-meadow stage
(d) Forest stage

Mishal Gul

Numerade Educator

Problem 106

Litter is decomposed by how many organisms among the following? Earthworm, Bacteria, Fungi, Mites
(a) 1
(b) 2
(c) 3
(d) 4

Asma Venkitta

Numerade Educator

Problem 107

The following are ecosystem services except
(a) Maintain biodiversity
(b) Crop pollination
(c) Storage site for carbon
(d) Flood

Kayla Scholl

Numerade Educator

Problem 108

In decomposition, complex organic compounds of detritus are converted to which of the following substances by decomposers?
(a) Carbon dioxide
(b) Water
(c) Inorganic nutrients
(d) All of these

Joanna Quigley

Numerade Educator

Problem 109

Driving force for an ecosystem is
(a) Primary producers
(b) Secondary producers
(c) Solar radiation
(d) Food chain

Jennifer Smith

Numerade Educator

Problem 110

Frog, snake and eagle belongs to
(a) Three trophic levels
(b) Two trophic levels
(c) Only one trophic level
(d) None of these

Hunza Gilgit

Numerade Educator

Problem 111

Ecosystem shows
(a) Homeostasis
(b) Mineral cycling
(c) Energy flow
(d) All of these

FZ

Fathima Zahra

Numerade Educator

Problem 112

Diagrammatic representation of different trophic levels of an ecosystem presents
(a) Energy flow
(b) Mineral cycling
(c) Food chain and food web
(d) Ecological pyramids

Hunza Gilgit

Numerade Educator

Problem 113

A plant eaten by a herbivorous animal which in turn is eaten by a carnivorous animal forms a
(a) Food web
(b) Food chain
(c) Food pyramid
(d) Food cycle

Madeline Buddendorf

Madeline Buddendorf

Numerade Educator

Problem 114

Which of the following statements is correct?
(a) Producers produce energy
(b) Consumers consume energy
(c) Decomposers decompose energy
(d) Producers transform energy

Danielle Ashley

Danielle Ashley

Numerade Educator

Problem 115

Food chain operating on decaying cow dung or organic remains is referred to as
(a) Secondary succession
(b) Secondary food chain
(c) Food web
(d) Detritus food chain

Qudsiya Anis

Numerade Educator

Problem 116

Biological equilibrium is maintained with the help of
(a) Producers and consumers
(b) Consumers and decomposers
(c) Herbivores and carnivores
(d) Photosynthesis and respiration

AG

Aimee Grayling

Numerade Educator

Problem 117

In ecosystem, the nonliving components are
(a) Less important than the living components.
(b) Equally important as those of the living components.
(c) More important than living components.
(d) None of the above

Aflah M

Numerade Educator

Problem 118

Cycling of material in ecosystem is entirely dependent upon
(a) Producers and consumers
(b) Primary producers and herbivores
(c) Herbivores and carnivores
(d) Producers and decomposers

AG

Aimee Grayling

Numerade Educator

Problem 119

In a terrestrial ecosystems such as forests, maximum energy is found in which trophic level?
(a) $\mathrm{T}_{1}$
(b) $\mathrm{T}_{2}$
(c) $\mathrm{T}_{3}$
(d) $\mathrm{T}_{4}^{2}$

Brett Donadeo

Numerade Educator

Problem 120

Trophic levels are formed by
(a) Only plants
(b) Only animals
(c) Only carnivores
(d) Organisms linked in food chains

Kai Medina

Numerade Educator

Problem 121

If $20 \mathrm{~kJ}$ energy is available at producer level, then how much energy will be transferred to the lion in the food chain: producer $\rightarrow$ deer $\rightarrow$ lion?
(a) $0.2 \mathrm{~J}$
(b) $0.02 \mathrm{~J}$
(c) $0.002 \mathrm{~J}$
(d) $2 \mathrm{~J}$

Joanna Quigley

Numerade Educator

Problem 122

Select the correct match for the below given stages of succession.
(a) A: Phytoplankton, B: Submerged plant, C: Submerged free floating plant stage, D: Reed swamp stage, E: Marsh-meadow stage, F: Scrub stages
(b) A: Marsh-meadow stage, B: Submerged free floating plant stage, C: Scrub stages, D:
Phytoplankton, E: Submerged plant, F: Reed swamp stage
(c) A: Scrub stages, B: Marsh-meadow stage, C: Phytoplankton, D: Reed swamp stage, E:
Submerged plant, F: Submerged free floating plant stage
(d) A: Scrub stages, B: Phytoplankton, C: Reed swamp stage, D: Marsh-meadow stage, E:
Submersed free floating pant stage, F: Submerged plant

Mishal Gul

Numerade Educator

Problem 123

Read the assertion and reason carefully to mark the correct option out of the options given below:
(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion.
(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
(c) If the assertion is true but the reason is false.
(d) If both the assertion and reason are false.
Assertion: Forest, grassland and desert are examples of terrestrial ecosystem.
Reason: Ecosystem is a functional unit of nature.

Hast Aggarwal

Numerade Educator

Problem 124

Assertion: Vertical distribution of different species occupying different levels is called stratification.
Reason: Tree occupy top vertical strata of forest.

Hast Aggarwal

Numerade Educator

Problem 125

Assertion: Secondary productivity is defined as the rate of formation of new organic matter by producers.
Reason: Secondary productivity $=$ GPP $-\mathrm{R}$.

Leah Lampen

Numerade Educator

Problem 126

Assertion: Decomposers break down complex organic matter into inorganic substances like $\mathrm{CO}_{2}, \mathrm{H}_{2} \mathrm{O}$ and nutrients.
Reason: Detritivore breakdown detritus into smaller particles.

Heather Thornton

Heather Thornton

Numerade Educator

Problem 127

Assertion: Of the incident solar radiation is less than 50 per cent of its PAR.
Reason: Plant captures 2 to 10 per cent of the PAR.

Qudsiya Anis

Numerade Educator

Problem 128

Assertion: Biomass of a species is expressed in terms of dry weight in more accurate than fresh weight.
Reason: Fresh weight is affected by environment condition.

Chaim Chernoff

Numerade Educator

Problem 129

Assertion: Pyramid of energy is always upright.
Reason: Energy flow is unidirectional and some energy is always lost as heat at each step.

Dheeraj Sharma

Numerade Educator

Problem 130

Assertion: Gradual and fairly predictable change in the species composition of a given area is called succession.
Reason: Succession and evolution are same.

FZ

Fathima Zahra

Numerade Educator

Problem 131

Assertion: Secondary succession is faster than primary succession.
Reason: Some soil or sediments are present.

FZ

Fathima Zahra

Numerade Educator

Problem 132

Assertion: Phosphorus cycle is sedimentary cycle.
Reason: Reservoir of phosphorus located in earth's crust.

Heather Thornton

Heather Thornton

Numerade Educator

Problem 133

Assertion: Length of food chain is limited.
Reason: Energy hypothesis explain it because of inefficiency of energy transfer along the chain.

April Townson

Numerade Educator

Problem 134

Assertion: Ecosystem is an open system.
Reason: Ecosystem exchange mass as well as energy from surrounding.

Prem Bijarniya

Numerade Educator

Problem 135

Assertion: Despite occupying about $70 \%$ of surface, the productivity of oceans is only 55 million to us.
Reason: Light and minerals are limiting factor for productivity of ocean.

Hast Aggarwal

Numerade Educator

Problem 136

Assertion: The pyramid of biomass in sea is generally inverted.
Reason: The biomass of fishes far exceeds that of phytoplankton.

VS

Vivek Singh

Numerade Educator

Problem 137

Assertion: The energy pyramid is always upright.
Reason: Some energy is always lost as heat at each step when energy flows from a particular trophic level to the next trophic level.

Alexander Clippinger

Alexander Clippinger

Numerade Educator

Problem 138

Assertion: In primary succession on rocks pioneer species are usually lichens.
Reason: They are able to secret acids to dissolve rocks helping in weathering and soil formation.

Sudhir Kumar

Numerade Educator

Problem 139

Assertion: Amount of nutrient present in the soil at any given time, in a given ecosystem is referred as the standing state.
Reason: Each trophic level has a certain mass of living material at particular time is known as the standing crop.

FZ

Fathima Zahra

Numerade Educator

Problem 140

Assertion: In terrestrial ecosystem, a large amount of energy passes through detritus food chain.
Reason: Energy for detritus food chain comes from sun.

Emily Marty

Numerade Educator