MCQs For NCERT Class 12 Biology Chapter 13 Organisms and Populations

Please refer to the MCQ Questions for Class 12 Biology Chapter 12 Organisms and Populations with Answers. The following Organisms and Populations Class 12 Biology MCQ Questions has been designed based on the latest syllabus and examination pattern for Class 12. Our experts have designed MCQ Questions for Class 12 Biology with Answers for all chapters in your NCERT Class 12 Biology book.

Organisms and Populations Class 12 MCQ Questions with Answers

See below Organisms and Populations Class 12 Biology MCQ Questions, solve the questions and compare your answers with the solutions provided below. 

Question. Plants which produce characteristic pneumatophores and show vivipary belong to
(a) halophytes
(b) psammophytes
(c) hydrophytes
(d) mesophytes.

Question. Presence of plants arranged into well defined vertical layers depending on their height can be seen best in
(a) tropical rainforest
(b) grassland
(c) temperate forest
(d) tropical savannah.

Question. It is much easier for a small animal to run uphill than for a large animal, because
(a) small animals have a lower O₂ requirement
(b) the efficiency of muscles in large animals is less than in the small animals
(c) it is easier to carry a small body weight
(d) smaller animals have a higher metabolic rate.

Question. An association of individuals of different species living in the same habitat and having functional interactions is
(a) ecosystem
(b) population
(c) ecological niche
(d) biotic community.

Question. Niche is
(a) all the biological factors in the organism’s environment
(b) the physical space where an organism lives
(c) the range of temperature that the organism needs to live
(d) the functional role played by the organism where it lives. 

Question. Pneumatophores occur in
(a) halophytes
(b) free-floating hydrophytes
(c) carnivorous plants
(d) submerged hydrophytes. 

Question. Most animals are tree dwellers in a
(a) temperate deciduous forest
(b) tropical rainforest
(c) coniferous forest
(d) thorn woodland. 

Question. Benthic organisms are affected the most by
(a) light reaching the forest floor
(b) surface turbulence of water
(c) sediment characteristics of aquatic ecosystems
(d) water-holding capacity of soil.

Question. Large woody vines are more commonly found in
(a) temperate forests
(b) mangroves
(c) tropical rainforests
(d) alpine forests. 

Question. Reduction in vascular tissue, mechanical tissue and cuticle is characteristic of
(a) mesophytes
(b) epiphytes
(c) hydrophytes
(d) xerophytes.

Question. Just as a person moving from Delhi to Shimla to escape the heat for the duration of hot summer, thousands of migratory birds from Siberia and other extremely cold northern regions ove to
(a) Western Ghat
(b) Meghalaya
(c) Corbett National Park
(d) Keoladeo National Park. 

Question. Which one of the following is not a parasitic adaptation?
(a) Development of adhesive organs
(b) Loss of digestive organs
(c) Loss of reproductive capacity
(d) Loss of unnecessary sense organs

Question. Quercus species are the dominant component in
(a) scrub forests
(b) tropical rainforests
(c) temperate deciduous forests
(d) alpine forests. 

Question. Praying mantis is a good example of
(a) camouflage
(b) mullerian mimicry
(c) warning colouration
(d) social insects. 

Question. More than 70% of world’s freshwater is contained in
(a) polar ice
(b) glaciers and mountains
(c) Antarctica
(d) Greenland.

Question. Animals have the innate ability to escape from predation. Examples for the same are given below. Select the incorrect example.
(a) Colour change in Chamaeleon
(b) Enlargement of body size by swallowing air in puffer fish
(c) Poison fangs in snake
(d) Melanism in moths

Question. Which one of the following pairs is mismatched?
(a) Tundra – Permafrost
(b) Savanna – Acacia trees
(c) Prairie – Epiphytes
(d) Coniferous forest– Evergreen trees 

Question Niche overlap indicates
(a) mutualism between two species
(b) active cooperation between two species
(c) two different parasites on the same host
(d) sharing of one or more resources between the two species.

Question. Annual migration does not occur in the case of
(a) arctic tern
(b) salmon
(c) siberian crane
(d) salamander. 

Question. What is true for individuals of same species?
(a) Live in same niche
(b) Live in same habitat
(c) Interbreeding
(d) Live in different habitat 

Question. Cause of mimicry is
(a) concealment
(b) offence
(c) defence
(d) both (b) and (c).

Question. Which part of the world has a high density of organisms?
(a) Deciduous forests
(b) Tropical rainforests
(c) Grasslands
(d) Savannah 

Question. In desert grasslands, which type of animals are relatively more abundant?
(a) Aquatic
(b) Fossorial
(c) Diurnal
(d) Arboreal 

Question. In which one of the following pairs is the specific
characteristic of a soil not correctly matched?
(a) Laterite – Contains aluminium compound
(b) Terra rosa – Most suitable for roses
(c) Chernozems – Richest soil in the world
(d) Black soil – Rich in calcium carbonate

Question. In which one of the following habitats does the diurnal temperature of soil surface vary most?
(a) Shrub land
(b) Forest
(c) Desert
(d) Grassland 

Question. During adverse season, therophytes survive by
(a) rhizomes
(b) seeds
(c) bulbs
(d) corms 

Question. Benthoic animals are those, which
(a) are submerged in area
(b) float on the sea surface
(c) are deep dweller in sea
(d) are floating (free) organisms. 

Question. The ‘niche’ of a species is meant for
(a) habitat and specific functions of a species
(b) specific place where an organism lives
(c) specific species function and its competitive power
(d) none of these. 

Question. The animals of cold countries have relatively shorter and poorly developed ears, eyes, hairs and other phenotypic characters. This is known by which law?
(a) Cope’s Law
(b) Dollo’s Law
(c) Allen’s Law
(d) Bergamann’s Law

Question. Plants such as Prosopis, Acacia and Capparis represent examples of tropical
(a) deciduous forests
(b) evergreen forests
(c) grasslands
(d) thorn forests. 

Question. Which of the following communities is more vulnerable to invasion by outside animals and plants?
(a) Temperate forests
(b) Oceanic island communities
(c) Mangroves
(d) Tropical evergreen forests 

Question. Study of inter-relationships between organisms and their environment is
(a) ecology
(b) ecosystem
(c) phytogeography
(d) ethology. 

Question. Soil particles determine its
(a) texture
(b) field capacity
(c) water holding capacity
(d) soil flora.

Question. Homeostasis is
(a) tendency of biological systems to change with change in environment
(b) tendency of biological systems to resist change
(c) disturbance of self regulatory system and natural controls
(d) biotic materials used in homeopathic medicines.

Question. Deep black soil is productive due to high proportion of
(a) sand and zinc
(b) gravel and calcium
(c) clay and humus
(d) silt and earthworm.

Question. Homeostasis is
(a) tendency to change with change in environment
(b) tendency to resist change
(c) disturbance in regulatory control
(d) plants and animal extracts used in homeopathy

Question. Which of the following is not an attribute of a population?
(a) Sex ratio
(b) Natality
(c) Mortality
(d) Species interaction

Question. The sum total of the populations of the same kind of organisms constitute
(a) colony
(b) genus
(c) community
(d) species. 

Question. Fertility of soil is measured by its ability to
(a) retain nutrients
(b) hold organic materials
(c) hold water
(d) support life.

Question. Carnivorous animals lions and leopards, occupy the same niche but lions predate mostly larger animals and leopards take smaller ones. This mechanism of competition is referred to as
(a) character displacement
(b) altruism
(c) resource partitioning
(d) competitive exclusion. 

Question. Which one of the following plants shows a very close relationship with a species of moth, where none of the two can complete its life cycle without the other?
(a) Hydrilla
(b) Yucca
(c) Banana
(d) Viola

Question. In a growing population of a country,
(a) pre-reproductive individuals are more than the reproductive individuals
(b) reproductive individuals are less than the postreproductive individuals
(c) reproductive and pre-reproductive individuals are equal in number
(d) pre-reproductive individuals are less than the reproductive individuals. 

Question. Which one of the following population interactions is widely used in medical science for the production of antibiotics?
(a) Commensalism
(b) Mutualism
(c) Parasitism
(d) Amensalism

Question. Mycorrhizae are the example of
(a) amensalism
(b) antibiosis
(c) mutualism
(d) fungistasis.

Question. Between which among the following, the relationship is not an example of commensalism?
(a) Orchid and the tree on which it grows
(b) Cattle Egret and grazing cattle
(c) Sea Anemone and Clown fish
(d) Female wasp and fig species

Question. Natality refers to
(a) death rate
(b) birth rate
(c) number of individuals leaving the habitat
(d) number of individuals entering a habitat.

Question. The principle of competitive exclusion was stated by
(a) C. Darwin
(b) G.F. Gause
(c) Mac Arthur
(d) Verhulst and Pearl.

Question. In which of the following interactions both partners are adversely affected?
(a) Parasitism
(b) Mutualism
(c) Competition
(d) Predation

Question. According to Darwin, the organic evolution is due to
(a) competition within closely related species
(b) reduced feeding efficiency in one species due to the presence of interfering species
(c) intraspecific competition
(d) interspecific competition. 

Question. Besides paddy fields, cyanobacteria are also found inside vegetative part of
(a) Equisetum
(b) Psilotum
(c) Pinus
(d) Cycas. 

Question. Which one of the following microbes forms symbiotic association with plants and helps them in their nutrition?         
(a) Azotobacter
(b) Aspergillus
(c) Glomus
(d) Trichoderma

Question. Between which among the following, the relationship is not an example of commensalism?   
(a) Orchid and the tree on which it grows
(b) Cattle Egret and grazing cattle
(c) Sea Anemone and Clown fish
(d) Female wasp and fig species

Question. Which of the following statements is false regarding predators?         
(a) Predators keep prey populations under control.
(b) Predators help in maintaining species diversity in a community.
(c) If a predator is not efficient, then the prey population would become extinct.
(d) Herbivores (predators) have a greater advantage since the plants cannot run away to avoid predation.

Question. If ‘+’ sign is assigned to beneficial interaction,‘–’ sign to detrimental and ‘O’ sign to neutral interaction, then the population interaction represented by ‘+’ ‘–’ refers to         
(a) mutualism
(b) amensalism
(c) commensalism
(d) parasitism.

Question. Which one of the following is not a parasitic adaptation?         
(a) Development of adhesive organs
(b) Loss of digestive organs
(c) Loss of reproductive capacity
(d) Loss of unnecessary sense organs

Question. Select the incorrect statement.          
(a) An overwhelming majority of animals and nearly all plants maintain a constant internal temperature.
(b) An orchid growing as an epiphyte on a mango branch is an example of commensalism.
(c) In brood parasitism, the parasitic bird lays its eggs in the nest of its host and lets the host to incubate them.
(d) Very small animals are rarely found in polar regions.

Question. Connel’s field experiment on the rocky sea coast of Scotland, where larger barnacle Balanus dominates the intertidal area and removes the smaller barnacle Chthamalus. This happened due to         
(a) parasitism
(b) predation
(c) mutualism
(d) competition.

Question. All the following interactions are mutualism,except         
(a) plant and animal relation for pollination
(b) association of algae and fungi in lichens
(c) association of cattle egret and grazing cattle
(d) association of fungi and roots of higher plants in mycorrhiza.

Question. Pneumatophores occur in         
(a) halophytes
(b) free-floating hydrophytes
(c) carnivorous plants
(d) submerged hydrophytes.

Question. Gause’s principle of competitive exclusion states that         
(a) no two species can occupy the same niche indefinitely for the same limiting resources
(b) larger organisms exclude smaller ones through competition
(c) more abundant species will exclude the less abundant species through competition
(d) competition for the same resources exclude species having different food preferences.