#13 Biology Class 12 Chapter 13 - Organisms and Population MHTCET / NEET MCQ
13 - Organisms and Population MCQ
(1) Which factor of an ecosystem includes plants, animals and microorganisms ?
(a) Biotic factor
(b) Abiotic factor
(c) Direct factor
(d) Indirect factor
Answer-
(a) Biotic factor
(2) A n assemblage of individuals of different species living in the same habitat and having functional interactions is .......... .
(a) Biotic community
(b) Ecological niche
(c) Population
(d) Ecosystem
Answer-
(a) Biotic community
(3) Association between sea anemone and Hermit crab in gastropod shell is that of .......... .
(a) Mutualism
(b) Commensalism
(c) Parasitism
(d) Amensalism
Answer-
(b) Commensalism
(4) Select the statement which explains best parasitism.
(a) One species is benefited.
(b) Both the species are benefited.
(c) One species is benefited, other is not affected.
(d) One species is benefited, other is harmed.
Answer-
(d) One species is benefited, other is harmed.
(5) Growth of bacteria in a newly inoculated agar plate shows .......... .
(a) exponential growth
(b) logistic growth
(c) Verhulst-Pearl logistic growth
(d) zero growth
Answer-
(c) Verhulst-Pearl logistic growth
(6) All ecosystems on the earth together form .......... .
(a) biosphere
(b) biome
(c) living world
(d) environment
Answer-
(a) biosphere
(7) What is the mean annual temperature in the region of Arctic and Alpine tundra ?
(a) About –10 to 2 °C
(b) About –2 to 2 °C
(c) About 0 to 5 °C
(d) About 5 to 10 °C
Answer-
(a) About –10 to 2 °C
(8) Which out of the following are the major biomes in India ?
(I) Desert (II) Grassland (III) Tropical rain forest (IV) Temperate forest (V)Coniferous forest (VI) Deciduous forest (VII) Sea coast (VIII)Tundra
(a) (II) (IV) (VI) (VII)
(b) (I) (II) (V) (VIII)
(c) (I) (III) (VI) (VII)
(d) (II) (III) (VI) (VIII)
Answer-
(c) (I) (III) (VI) (VII)
(9) Important key elements that bring about variations in the different habitats are .......... .
(a) temperature, water, light and soil
(b) salinity, pollutants, water
(c) modern developmental parameters in the region
(d) scientific progress and technological innovations
Answer-
(a) temperature, water, light and soil
(10) Which out of the following is the most ecologically relevant factor ?
(a) Water
(b) Temperature
(c) S alinity
(d) Wind speed
Answer-
(b) Temperature
(11) Animals that can tolerate a narrow range of temperature are ..........
(a) stenothermal
(b) eurythermal
(c) poikilothermic
(d) homeothermic
Answer-
(a) stenothermal
(12) Animals that can tolerate a narrow range of salinity are ..........
(a) euryhaline
(b) anadromous
(c) catadromous
(d) stenohaline
Answer-
(d) stenohaline
(13) What is the source of energy in the depths of more than 500 m in the oceans ?
(a) Sunlight
(b) Wind energy
(c) Dead and decaying matter
(d) Phytoplankton
Answer-
(c) Dead and decaying matter
(14) Which factor does not determine percolation and water holding capacity of the soil ?
(a) Soil composition
(b) Grain size
(c) Aggregation of soil particles
(d) Vegetation on that soil
Answer-
(d) Vegetation on that soil
(15) Which factors of soil does not determine the vegetation in any area ?
(a) pH
(b) mineral composition
(c) topography
(d) types of microorganisms
Answer-
(d) types of microorganisms
(16) Find the odd one out :
(a) Dormancy
(b) Hibernation
(c) Aestivation
(d) Migration
Answer-
(d) Migration
(17) Which of the following ability is present in the desert animals ?
(a) Ability to concentrate urine.
(b) Ability to remain inside the shelters and escape need of water.
(c) Ability to derive water from all the fruits.
(d) Ability to absorb water from air.
Answer-
(a) Ability to concentrate urine.
(18) Which of the statement does not describe the adaptation of the desert plants ?
(a) Desert plants have a thick cuticle on their leaf surfaces.
(b) Desert plants have their stomata arranged in sunken pits.
(c) Desert plants have a special photosynthetic pathway called CAM.
(d) Desert plants have soft stems and large leaves.
Answer-
(d) D esert plants have soft stems and large leaves.
(19) What is the use of CAM type of photosynthetic pathway for the desert plants ?
(a) It enables their stomata to remain closed during day time.
(b) It requires less sunlight for the photosynthesis.
(c) It requires less amount of chlorophyll during photosynthesis.
(d) The water absorbed from the soil by the plants during CAM photosynthetic pathway is less.
Answer-
(a) It enables their stomata to remain closed during day time.
(20) In which plant photosynthetic function is taken over by the flattened stems ?
(a) Nephrolepis
(b) Cycas
(c) Opuntia
(d) Zea mays
Answer-
(c) Opuntia
(21) What is Allen’s rule ?
(a) Mammals from colder climates generally have shorter ears and limbs to minimise heat loss.
(b) Mammals have constant temperature of the body in spite of their varied habitats.
(c) Mammals can be oviparous at times.
(d) The ecosystem of cold climate regions is equally occupied with mammals, birds and reptiles.
Answer-
(a) Mammals from colder climates generally have shorter ears and limbs to minimise heat loss.
(22) Sunken stomata is the characteristic feature of ..........
(a) hydrophyte
(b) mesophyte
(c) xerophyte
(d) halophyte
Answer-
(c) xerophyte
(23) Which of the following pairs is correctly matched ?
(a) Uricotelism – aquatic habitat
(b) Parasitism – intra-specific relationship
(c) Excessive perspiration – xeric adaptation
(d) Stream-lined body – aquatic adaptation
Answer-
(d) Stream-lined body – aquatic adaptation
(24) World population day is observed on .......... .
(a) 11th July
(b) 16th September
(c) 23rd October
(d) 1st December
Answer-
(a) 11th July
(25) World Environment day is celebrated on .......... .
(a) 22nd April
(b) 5th June
(c) 1st October
(d) 16th November
Answer-
(b) 5th June
(26) World Earth day is observed on .......... .
(a) 22nd April
(b) 5th June
(c) 21st October
(d) 26th November
Answer-
(a) 22nd April
(27) World ozone day is celebrated on .......... .
(a) 5th June
(b)16th September
(c) 1st October
(d) 23rd October
Answer-
(b) 16th September
(28) A group of individuals belonging to the same species within an ecosystem is called a .......... .
(a) community
(b) habitat
(c) population
(d) specific group
Answer-
(c) population
(29) The populations of different species that live and interact together in the ecosystem are called .......... .
(a) community
(b) habitat
(c) population
(d) interspecies
Answer-
(a) community
(30) If .......... do not occur in an ecosystem, the survival of organisms may not take place and functioning of ecosystem is lost.
(a) interactions
(b) struggle
(c) reproduction
(d) none of the above
Answer-
(a) interactions
(31) If in a pond there were 200 lotus plants last year and through reproduction 20 new plants are added, taking the current population to 220, what is the natality rate of the lotus for that year ?
(a) 0.2
(b) 0.4
(c) 0.1
(d) 1.0
Answer-
(c) 0.1
(32) During laboratory experiments, 30 fishes died from an aquarium tank having 150 fishes during one month. What is the rate of mortality of fishes per month ?
(a) 0.2
(b) 0.3
(c) 0.4
(d) 0.5
Answer-
(a) 0.2
(33) Which of the following is correct statement ?
(a) Natality can never be controlled in any population.
(b) If mortality is more than natality, the density of population declines.
(c) Natality and mortality are always same for every population.
(d) If natality is more than mortality the population size declines.
Answer-
(b) If mortality is more than natality, the density of population declines.
(34) What is the apt definition of density ?
(a) The capacity of a population to sustain.
(b) The total number of genes in a population.
(c) The total number of individuals in a population per unit area.
(d) The total number of births taking place.
Answer-
(c) The total number of individuals in a population per unit area.
(35) On which of the following factors is growth rate of a population dependent ?
(a) Density and natality
(b) Natality and age structure
(c) Mortality and density
(d) Natality and mortality
Answer-
(a) Density and natality
(36) When pre-reproductive age group is large in a population, what will be the growth rate of that population ?
(a) Steady
(b) Rapid
(c) Declining
(d) None of these
Answer-
(b) Rapid
(37) When pre-reproductive and postreproductive age group is same in structure, the population is .......... .
(a) declining
(b) increasing
(c) steady
(d) disappearing
Answer-
(c) steady
(38) In which type of interactions, interacting species do not live closely together ?
(a) Competition
(b) Parasitism
(c) Commensalism
(d) Predation
Answer-
(d) Predation
(39) Name the interaction in which one species is harmed but the other remains unaffected.
(a) Commensalism
(b) Parasitism
(c) Amensalism
(d) Competition
Answer-
(c) Amensalism
(40) Choose the correct statement from the following :
(a) Carnivores are the only predators in any ecosystem.
(b) Herbivores are in a broad ecological context not very different from predators.
(c) S parrow eating grain is not a predator.
(d) Predation and parasitism are one and the same.
Answer-
(b) Herbivores are in a broad ecological context not very different from predators.
(41) What is the meaning of symbiosis ?
(a) Living together
(b) Breeding together
(c) Fighting with each other
(d) Feeding together
Answer-
(a) Living together
(42) Gause’s ‘Competitive Exclusion Principle’ can work only when .......... .
(a) the resources are limited
(b) the resources are abundant
(c) the inferior species and superior species do not need same resources
(d) only when there is interspecific competition
Answer-
(a) the resources are limited
(43) The word commensalism means .......... .
(a) on the either side of the table
(b) sharing the table
(c) eating at the table of other
(d) on the top of the table 1 2 3 4
Answer-
(b) sharing the table
(44) Which of the following is not a classical example of commensalism ?
(a) An orchid growing as an epiphyte on a mango branch.
(b) Barnacles growing on the back of a whale.
(c) The cattle egret and grazing cattle.
(d) Lichen seen on the tree.
Answer-
(d) Lichen seen on the tree
(45) Calotropis plant is poisonous for herbivores as it is rich in .......... .
(a) opium
(b) cardiac glycosides
(c) quinine
(d) strychnine
Answer-
(b) cardiac glycosides
(46) Term ecology was first used by .......... .
(a) Grinnell
(b) Reiter
(c) Haeckel
(d) Darwin
Answer-
(b) Reiter
(47) Who introduced subject ecology to the world.
(a) Reiter
(b) Grinnell
(c) Darwin
(d) E. Haeckel
Answer-
(d) E. Haeckel
(48) The term niche was first time used by ....... .
(a) Grinnell
(b) Haeckel
(c) Mendel
(d) Darwin
Answer-
(a) Grinnell
