Biology MCQ
#14 Biology Class 12 Chapter 14 - Ecosystems and Energy Flow MHTCET / NEET MCQ
Ecosystems and Energy Flow MCQ
(1) Which one of the following has the largest population in a food chain ?
(a) Producers(b) Primary consumers(c) Secondary consumers(d) Decomposers
Answer-
(a) Producers
(2) The second trophic level in a lake is ……… .
(a) Phytoplankton(b) Zooplankton(c) Benthos(d) Fishes
Answer-
(b) Zooplankton
(3) Secondary consumers are ……… .
(a) Herbivores(b) Producers(c) Carnivores(d) Autotrophs
Answer-
(c) Carnivores
(4) W hat is the % of photosynthetically active radiation in the incident solar radiation ?
(a) 100%(b) 50%(c) 1 – 5%(d) 2 – 10%
Answer-
(b) 50%
(5) Give the term used to express a community in its final stage of succession ?
(a) End community(b) Final community(c) Climax community(d) Dark community
Answer-
(c) Climax community
(6) After landslide which of the following type of succession occurs ?
(a) Primary(b) Secondary(c) Tertiary(d) Climax
Answer-
(a) Primary
(7) Which of the following is most often a limiting factor of the primary productivity in any ecosystem ?
(a) Carbon(b) Nitrogen(c) Phosphorus(d) Sulphur
Answer-
(c) Phosphorus
(8) What is a true about ecosystem ?
(a) Primary consumers are least dependent upon producers.(b) Primary consumers outnumber the producers.(c) Producers are more than primary consumers.(d) Secondary consumers are the largest and most powerful.
Answer-
(c) Producers are more than primary consumers.
(9) In an ecosystem, which shows one way passage ?
(a) Free energy(b) Carbon(c) Nitrogen(d) Potassium
Answer-
(a) Free energy
(10) How many are biotic components from the following ?
Climate, carbohydrates, microbes, green plants, lipids, water, proteins, photosynthetic bacteria, chemosynthetic bacteria, herbivores, carnivores.
(a) 6(b) 5(c) 4(d) 7
Answer-
(a) 6
(11) From the following, which is the basic requirement for any type of ecosystem to function and sustain ?
(a) Constant output of solar energy(b) Constant input of solar energy(c) Organic substances(d) Organic substances dissolved in water
Answer-
(b) Constant input of solar energy
(12) Which type of spatial patterns noticed in ecosystem structure ?
(a) Zonation(b) Stratification(c) Zonation and stratification(d) Zonation, stratification and distribution
Answer-
(c) Zonation and stratification
(13) In which strata of any aquatic body there will be maximum photosynthesis ?
(a) Bottom deposits(b) Middle strata of a water body(c) Near coastal region(d) The depth till where sunlight can reach
Answer-
(d) The depth till where sunlight can reach
(14) Which spatial pattern occurs vertically in an ecosystem ?
(a) Zonation(b) Stratification(c) Y-shaped pattern(d) Pyramid
Answer-
(b) Stratification
(15) Which of the following is one of the characteristics of a biological community ?
(a) Sex ratio(b) Stratification(c) Natality(d) Mortality
Answer-
(b) Stratification
(17) Which of the following is the basic requirement for any ecosystem to function and sustain ?
(a) Aconstant input of solar energy(b) Ample water availability(c) Cool temperatures(d) Enough winds and currents around
Answer-
(a) deer, rabbit, frog, rat
(18) Which one is the most accurate definition of primary production ?
(a) The amount of the food produced by plants.(b) The amount of food available to herbivores.(c) The amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis.(d) The amount of crop produced by farmer.
Answer-
(c) The amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis.
(19) Primary production is expressed in terms of ......... .
(a) kg / area(b) weight (g -2) or energy (kcalm-2)(c) energy in food calories(d) calories / sq. m.
Answer-
(b) weight (g -2) or energy (kcalm-2)
(20) Considerable amount of GPP is utilized by plants in ......... .
(a) metabolism(b) respiration(c) homeostasis(d) excretion
Answer-
(b) respiration
(21) Which one is the most appropriate definition of secondary productivity ?
(a) Secondary productivity is the rate of formation of new organic matter by consumers.(b) Secondary productivity is the amount of food consumed by the carnivores.(c) Secondary productivity is the amount of food consumed by the producers.(d) Secondary productivity is the amount of energy lost in the food chain.
Answer-
(a) Secondary productivity is the rate of formation of new organic matter by consumers.
(22) Choose the factor on which primary productivity does not depend.
(a) The plant species inhabiting a particular area(b) Amount of primary consumers dependent on plants(c) A vailability of nutrients(d) Photosynthetic capacity of plants
Answer-
(b) A mount of primary consumers dependent on plants.
(23) The annual net primary productivity of the whole biosphere is approximately ......... billion tonnes (dry weight) of organic matter.
(a) 10(b) 50(c) 100(d) 170
Answer-
(d) 170
(24) The rate at which light energy is changed into chemical energy of organic molecules in ecosystems is ......... .
(a) net primary productivity(b) gross primary productivity(c) net secondary productivity(d) gross secondary productivity
Answer-
(b) gross primary productivity
(25) What is net primary productivity ?
(a) Total rate of photosynthesis(b) Rate of energy storage by consumer(c) Amount of organic matter stored by plants(d) Rate of energy used
Answer-
(c) Amount of organic matter stored by plants
(26) Which is the correct sequence of the steps decomposition process ?
(a) Fragmentation -> Mineralization -> Catabolism -> Humification -> Leaching(b) Leaching -> Catabolism -> Humification -> Fragmentation -> Mineralization(c) Fragmentation -> Leaching -> Catabolism -> Humification -> Mineralization(d) Catabolism -> Humification -> Fragmentation -> Leaching -> Mineralization
Answer-
(c) Fragmentation -> Leaching -> Catabolism -> Humification -> Mineralization
(27) Match the columns :
1. Fragmentation i. R elease of inorganic nutrients
2. Leaching ii. Bacterial and fungal enzymes
3. Catabolism iii. A ccumulation of dark amorphous substance
4. Humification iv. Precipitated as unavailable salts
5. Mineralization v. Break down into smaller pieces 1 2 3 4 5
(a) v ii iii i iv(b) v iv ii iii i(c) ii iii iv v i(d) iii v iv i ii
Answer-
(b) v, iv, ii, iii. i
(28) 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
Answer-
(a) low moisture content
(29) Small amount of energy sustains the entire living world is only ......... of the PAR.
(a) 20 – 25%(b) 10 – 15%(c) 2 – 10%(d) 1 – 2%
Answer-
(c) 2 – 10%
(30) Choose incorrect statement out of the following :
(a) Much larger fraction of energy flows through the DFC than through the GFC.(b) Some of the organisms of DFC are prey to the GFC animals.(c) In an aquatic ecosystem, GFC is the major conduit for energy flow.(d) Much less fraction of energy flows through the GFC than through the DFC.
Answer-
(d) Much less fraction of energy flows through the GFC than through the DFC
(31) In an ecosystem, bacteria are considered as ......... .
(a) primary consumers(b) microconsumers(c) macroconsumers(d) secondary consumers
Answer-
(b) microconsumers
(32) Which of the following can be a top carnivore of marine ecosystem ?
(a) Zooplankton(b) Sea cucumber(c) Sea horse(d) Kingfisher
Answer-
(d) Kingfisher
(33) Identify the possible link ‘A’ in the following food chain.
Plant -> Insect -> Frog -> ‘A’ -> Eagle
(a) Rabbit(b) Wolf(c) Cobra(d) Parrot
Answer-
(c) Cobra
(34) Why is the pyramid of biomass inverted in sea ?
(a) Because plants are absent.(b) Because fishes have less biomass.(c) Because phytoplankton which are primary producers have less biomass.(d) Because primary producers have more biomass.
Answer-
(c) Because phytoplankton which are primary producers have less biomass.
(35) Identify the wrong statement in relation to concept of pyramids.
(a) Pyramid of energy is always upright, can never be inverted.(b) In most ecosystems, all the pyramids of number of energy and biomass are upright.(c) Inverted pyramid of biomass is observed in pond ecosystem as small standing crop of phytoplankton supports larger zooplanktons.(d) Pyramid of biomass in sea is upright because fishes feed on standing crop of planktons.
Answer-
(d) Pyramid of biomass in sea is upright because fishes feed on standing crop of planktons.
(37) From the following, which is not a fate of carbon in plants ?
(a) Released in atmosphere through transpiration.(b) Liberated in atmosphere through respiration.(c) Consumed by animal in the form of food.(d) Remains as it is as organic matter when plant dies.
Answer-
(a) R eleased in atmosphere through transpiration.
(38) Bacterial role in carbon cycle is ......... .
(a) photosynthesis(b) chemosynthesis(c) assimilation(d) breakdown of organic matter
Answer-
(d) breakdown of organic matter
(39) Which out of the following is the major reservoir of carbon ?
(a) Animal bodies(b) Fruits(c) Ocean(d) Coal mines
Answer-
(c) Ocean
(40) Which act of human beings has great impact on carbon cycle ?
(a) Breaking of limestone(b) Building up of limestone reefs(c) Burning of fossil fuels(d) Volcanic eruption
Answer-
(c) Burning of fossil fuels
(41) Rock phosphates are brought into circulation by the process of ......... .
(a) combustion(b) sedimentation(c) weathering(d) absorption
Answer-
(c) weathering
(42) In animals this structure is not containing phosphorus.
(a) Bones(b) Shells(c) Teeth(d) Hairs
Answer-
(d) Hairs
(43) Phosphorus is not a major constituent of ......... .
(a) DNA(b) Proteins(c) RNA(d) ATP
Answer-
(b) Proteins
(44) Secondary Succession takes place on / in :
(a) Newly cooled lava(b) Bare rock(c) Degraded forest(d) Newly created pond
Answer-
(c) Degraded forest
(45) Vertical distribution of different species occupying different levels in a biotic community is known as ......... .
(a) Pyramid(b) Divergence(c) Stratification(d) Zonation
Answer-
(c) Stratification
(46) The developmental stages of ecological succession are called ......... .
(a) serial stages(b) seral stages(c) cereal stages(d) trophic levels
Answer-
(b) seral stages
(47) What is the peculiarity of pioneers in succession ?
(a) They are always heterotrophic components.(b) They always face favourable growth conditions.(c) They are the most successful terminal occupants of the area.(d) They face adverse conditions and get established there.
Answer-
(d) They face adverse conditions and get established there.
(48) What are pioneers ?
(a) First seral stage(b) Heterotrophic seral stage(c) Terminal (last) seral stage(d) Final climax community
Answer-
(a) First seral stage
(49) The stable community established in an area is known as ......... .
(a) pioneer community(b) climax community(c) equilibrium community(d) autotrophic community
Answer-
(b) climax community
(50) The entire sequence of communities that successively change in a given area are called ......... .
(a) climax(b) sere(c) pioneer(d) standing population
Answer-
(b) sere
(51) The primary succession refers to the development of communities on a ......... .
(a) freshly cleared crop field(b) forest clearing after devastating fire(c) pond, freshly filled with water after a dry phase(d) Newly-exposed habitat with no record of earlier vegetation
Answer-
(d) Newly-exposed habitat with no record of earlier vegetation
(52) Which is the most important service provided by environment ?
(a) Release of oxygen(b) Formation of ozone layer(c) Carbon assimilation in photosynthesis(d) Agents of pollination
Answer-
(c) Carbon assimilation in photosynthesis
