MCQ Questions Chapter 13 Organisms and Populations Class 12 Biology

Please refer to MCQ Questions Chapter 13 Organisms and Populations Class 12 Biology with answers provided below. These multiple-choice questions have been developed based on the latest NCERT book for class 12 Biology issued for the current academic year. We have provided MCQ Questions for Class 12 Biology for all chapters on our website. Students should learn the objective based questions for Chapter 13 Organisms and Populations in Class 12 Biology provided below to get more marks in exams.

Chapter 13 Organisms and Populations MCQ Questions

Please refer to the following Chapter 13 Organisms and Populations MCQ Questions Class 12 Biology with solutions for all important topics in the chapter.

MCQ Questions Answers for Chapter 13 Organisms and Populations Class 12 Biology

Question- The maintenance of favourable internal conditions, by self-regulated mechanisms, even though there are changes in the environment, is known as
(a) Homeostasis 
(b) Entropy
(c) Enthalpy 
(d) Steady state

Question– Maximum trapping of solar energy is observed in
(a) Planting trees
(b) Cultivating crops
(c) Growing algae in tank
(d) Growing grasses

Question– Arrange the following ecosystems in the decreasing order of their mean net primary productivity (tons/hectare/year).
I. Tropical deciduous forest
II. Temperate coniferous forest
III. Tropical rain forest
IV. Temperate deciduous forest
V. Desert scrub
(a) III > I > IV > II > V 
(b) II > IV > I > III > V
(c) III > I > II > IV > V 
(d) IV > II > III > I > V

Question– The age pyramid for human population is shown below.

Which of the following conclusion can be draw from the given age pyramid?
(a) It represent that the population is young and growing.
(b) It is pyramid of declining population.
(c) It show that the population is stable
(d) It shown that the population size is fluctuating.

Question– Introduction of exotic species in an area can have deleterious effects on biological communities by
(a) Displacing native species
(b) Preying on native species
(c) Competing with native species for food /shelter
(d) All of above

Question– Biosphere are different from national park a
(a) Humans are not integral part of biosphere reserve
(b) Plants and animals are protected in biosphere reserve
(c) Humans are an integral part of biosphere reserve
(d) Only plants are protected in an IN-situ environment

Question– Which of the following In sewage treatment removes suspended solids?
(a) Tertiary treatment
(b) Secondary treatment
(c) Primary treatment
(d) Quarternary treatment

Question– The graph shows two types of the population growth curve ‘A’. Exponential and ‘B’. Logistic. Which of the following graph models is considered to be the more realistic one?

(a) Logistic curve 
(b) Exponential curve
(c) Both(a) and (b) 
(d) None of the above

Question– Species with small world populations that are not endangered or vulnerable at present, but are at the risk are called
(a) Critically endangered 
(b) Lower risk
(c) Rare 
(d) Extinct

Question– If the birth rate is 100, the death rate is 10 and the number of individuals in a population group is 1000, then what will be the intrinsic rate of natural increase of the population?
(a) 900 
(b) 90 
(c) 1090 
(d) 890

Question– Which of the following statement is not correct?
(a) Ecosystem is an open system for energy
(b) Ecosystem is self-sustaining and dynamic structure
(c) Sun is the ultimate source of energy for any ecosystem except hydrothermalvent
(d) In an artificial ecosystem flow of energy is not unidirectional

Question– Identify the correct type of food chain.
Dead animals → Blow fly maggots → Common frog →Snakes
(a) Grazing food chain
(b) Detritus food chain
(c) Decomposer food chain
(d) Predator food chain

Question– The products resulting from atmospheric reaction of hydrocarbons and nitrogen oxides in the presence of sunlight are called:
(a) Primary pollutants 
(b)Secondary pollutants
(c) Tertiary pollutants 
(d) Non- pollutants

Question– The Abingdon tortoise became extinct on Galapagos island within a decade of the introduction of goats. This is an example of
(a) Resource partitioning
(b) Competitive release
(c) Competitive inclusion
(d) Interference competition

Question– Choose the correct statement about the patterns of biodiversity
(a) The diversity of plants and animals is uniform and evenly distributed throughout the world.
(b) The tropics harbor more species than the temperate or polar regions.
(c) Speciation is a function of time as the tropical latitudes have been disturbed by frequent glaciations in the past.
(d) Lesser solar energy in the temperate regions Contributes to higher productivity and greater diversity in species.

Question- The term ‘precipitation’ includes
(a) rain
(b) snow
(c) hails
(d) all forms of water that fall to the ground.

Question- A majority of organisms which are restricted to narrow range of temperature are called as
(a) stenothermal
(b) endothermal
(c) ectothermal
(d) eurythermal

Question- The salinity in sea water in parts per thousand (ppt) ranges between
(a) 5-15%
(b) 30-35%
(c) 50-75%
(d) more than 100%

Question- Deep (>500m) in the oceans, the environment is perpetually dark and its inhabitants are not aware of the existence of a celestial source of energy called_________.
(a) ATP
(b) photosynthesis
(c) sun
(d) light

Question- The benthic organisms
(a) live near the sea bottom.
(b) found in open water.
(c) always live at the depth of 50-100 m.
(d) live outside water.

Question- Elephants use their ears to dump heat to the environment. What mechanisms might they employ to increase heat loss from ears?
(a) Increased convection due to flapping of the ears
(b) Moving into the sun
(c) Increased blood flow to the ears
(d) a and c

Question- I. Organisms living in oceans, lakes and rivers face water-related problems.
II. Euryh ne can tolerate a wide range of s nities
III. Stenoh ne are restricted to a narrow range of s nities
IV. No fresh water animals cannot live for long in sea water but sea animals can live in fresh water for long tim because of osmotic balance
V. The salt concentration is less than 5% in inland water, 30-35% in sea and >100% in some hypers ne lagoonj
(a) All are correct
(b) All are false
(c) Only IV is wrong
(d) Only I, III, V are correct

Question- A regional ecological unit having a specific climate is –
(a) Biome
(b) Landscape
(c) Ecosystem
(d) Biotic community

Question- Find out the false one –
(a) Texture of soil depends upon of size of mineral particles
(b) Soil aeration is inversely proportional to water holding capacity
(c) Waterlogged soil does not suit plants as it creates anaerobic environment
(d) Availability of minerals in soil is independent of soil pH

Question- Which of the following is not a part of an organism’s physical environment?
(a) Temperature
(b) Water
(c) Shade
(d) Other organisms

Question- If 4 individuals in a laboratory population of 40 fruitflies died during a specific time (a week) interval, the death rate in the population per week is –
(a) 1
(b) 0.1
(c) 10
(d) 400

Question- Ecology is basically concerned with four levels of biology organizations. These levels are –
(a) Organisms, populations, communities and biomes
(b) Organisms and communities, species and population
(c) Species, populations, biomes and organisms
(d) Organisms, populations, biomes and species

Question- Which of the following accounts for the formation of major biomes?
(a) Annual variations in intensity of temperature
(b) Annual variations in intensity and duration of temperature
(c) Annual variation in precipitation
(d) bandc

Question- The location of terrestrial biomes is strongly influenced by –
(a) Which animal species live in the area
(b) Climate
(c) Other nearby biomes
(d) Which plant species live in the area

Question- A few organisms can tolerate and thrive a wide range of temperature. Such animals are called _______.Avast majority of animals are restricted to a narrow range of temperature. Such animals are called ______.
(a) Eurythermal, stenothermal
(b) Stenothermal, eurythermal
(c) Thermoscopic, Unthermoscopic
(d) Thermophobic, thermophilic

Question- Each of the following is an important factor in determining the productivity of fresh water lake except –
(a) Nutrients
(b) Depth
(c) Proximity to marine coast
(d) Temperature

Question- The nature of soil in a given area is independent of –
(a) Climate
(b) Weathering process
(c) Weather soil is transported or sedimentary and how the soil development occurred
(d) None of the above

Question- Size of population can be decreased by –
(a) A higher birth rate
(b) Immigration
(c) Emigration
(d) Increase in food availabili

Question- In regions of hot temperatures and wet climate, you will most likely find _______ biomes, whereas in the regions of hot temperature and dry climate you will find _______.
(a) Desert, tropical
(b) temperature, arid
(c) Tropical, desertt
(d) Tundra, chaparral

Question- Choose the odd out w.r.t structure formed in the different organisms during suspended phase.
(a) Bacteria – Thick walled spores
(b) Higher plants – Seeds, vegetative propagules
(c) Zooplankton – Diapause stage
(d) Ectothermic organisms – Torpid state during favourable season

Question- I. Thermoregulation, osmoregulation and excretion are mechanisms that moderate change in the body.
II. 99% animals and almost all plants are confomers
III. Heat loss or heat gain is a function of surface area.
IV. Thermoregulation energetically least expensive process for many organisms like shrews and humming birds.
V. 99% animals are thermoregulator
VI. Archaebacteria cannot tolerate high temperature
(a) I and II are wrong
(b) IV, V and VI are wrong
(c) None is wrong
(d) All are wrong

Question- Which of the factors dictates the types of animal in a habitat –
(a) pH of the soil
(b) Type of benthic animals
(c) Types of forests
(d) Types of vegetation that support them

Question- Many animals use the diurnal and seasonal variations in light intensity and photoperiod as cues timming of –
(a) For age only
(b) Reproductive activities only
(c) Migration only
(d) AII

Question- To a large extent, the vegetation of an area is determined by –
(a) Physical + chemical properties of soil only
(b) pHofsoil
(c) Physical + Chemical properties of soil and topography
(d) Type of minerals in soil

Question- Human can get homeostasis through-
(a) Only physiological means
(b) Only physical means
(c) Both physiological and physical means
(d) neither physiological nor physical means

Question- I. Basking by desert lizards in sun
II. Hiding in burrows by some animals
III. Wearing of woolen clothes
IV. Thermal gaping
The above are examples of –
(a) Scansorial adaptation
(b) Behavioural adaptation
(c) Fossorial adaptation
(d) Cursorial adaptation

Question- Seasons are influenced by-
(a) The tilt of earth on its axis
(b) The amount of solar radiation reaching earth’s surface
(c) Earth’s movement around the sun
(d) All

Question- Select the false statement –
(a) Average temperature on land varies seasonally
(b) Temperature progressively decreases from pole to equator
(c) Temperature progressively decreases from plains to mountain tops
(d) Our intestine is a unique habitat for hundreds of species of microbes

Question- The ultimate source of energy for all ecosystems on earth is –
(a) Photosynthesis
(b) Sun
(c) ATP
(d) Creatine phosphate

Question- Which one is correct?
I. In a hot climate.reptiles can maintain a constant body temperature in the day by behavioural regulation.
II. The body temperature of thermoconformers changes with ambient temperature.
III. In aquatic osmoconformers, the osmolarity of. body fluids changes with that of ambient water.
IV. Small animals have a larger surface area relative their volume, they tend to lose body heat very fast when it is cold outside, then they have to expend much energy to generate body heat through metabolism.
(a) All
(b) None
(c) Only IV
(d) I, II, III

Question- Snow leopards are not found in Kerala forests. Which factor is responsible for it?
(a) Temperature
(b) Soil
(c) Water
(d) Light

Question- Which of the following might contribute to determining an organism’s habitat?
(a) Amount of sunlight
(b) Temperature of soil
(c) Humidity and other organisms
(d) AII

Question- I. Mango trees cannot grow in temperate countries like Canada and Germany
II. Snow leopards are not found in Kerala.
III. Tuna fish are rarely caught beyond tropical latitude in the ocean.
IV. Average temperature exceeds 100°C in thermal springs and hydrothermal vents.
V. In polar areas and high altitudes temperature goes to 70°C.
VI. Temperature goes to > 50°C in tropical desert in summer.
Which of the above statements are false?
(a) I only
(b) II and III only
(c) Vonly
(d) V and VI only

Question- Next to temperature, which is the most important factor influencing the life of organisms?
(a) Light
(b) Soil
(c) Water
(d) Wind velocity

Question- Birth rate is 100, death rate is 10. Number of individuals in population group is 1000, What is the percentage of natural growth rate?
(a) 0.09%
(b) 9.0%
(c) 0.9%
(d) 90%

Question- What are the key elements that lead to so much variation in the physical and chemical conditions of different habitats?
(a) Temperature and Sight
(b) Soil and water
(c) Only soil
(d) Temperature, light, soil and water

Question- Life-
(a) Originated on earth in water
(b) Is sustainable with water only
(c) Is possible without water
(d) Both a and c are correct

Question- Major biomes of India include –
(a) Tropical rain forest
(b) Deciduous forest
(c) Desert and sea coast
(d) All

Question- Which of the following statement is false w.r.t adaptations?
(a) Many xerophytic plants have thick cuticle on leaf epidermis, sunken stomata
(b) Some xerophytic plants have special photosynthetic pathway (CAM) that enables their stomata close during day
(c) Opuntia has spines (modified leaves), photosynthetic phylloclade (stem)
(d) All adaptations are genetically fixed in all organisms

Question- Animals having a built-in thermostal to maintain constant body temperature are –
(a) Biothermic
(b) Poikilothermic
(c) Oligothermic
(d) Homeothermic

Question- Organisms have evolved various mechanisms to maintain homeostasis to perform its physiological and biochemical functions. This can be obtained through –
(a) Regulation
(b) Conformation
(c) Migration or suspension
(d) AII

Question- Deep (> 500m) in the oceans inhabitants are not aware of existence of a celestial source of energy called
(a) Sun
(b) ATP
(c) Photosynthesis
(d) Chemosynthesis

Question- Percolation and water holding capacity of soil is dependent upon –
(a) Soil composition, grain size and aggregation
(b) pH of soil
(c) Colour of soil
(d) holard

Question- Find out false one-
(a) Mammals from colder climate generally have shorter ears and limbs to minimise heat loss
(b) Some organisms have behavioural adaptations that allow them to respond quickly to a stressful situation
(c) Some organisms possess adaptations that are physiological which allow them to respond quickly to a stressful situation
(d) A large variety of invertebrates and fish live at great depths in the ocean where the pressure could be > 100 times than the normal atmospheric pressure

Question- False statement is –
(a) habitat includes both biotic and abiotic factors
(b) Ecology at the organismic level is essential physiological ecology
(c) Abiotic and biotic components interact constantly with each other
(d) None of the above

Question- Choose the odd one out w.r.t adaptations in the organisms –
(a) biochemical adaptation are seen in organisms living in great depth of the ocean to face crushing pressure
(b) en’s rule is seen in mammals living in colder climates
(c) Altitude sickness is caused because of body not getting enough oxygen due to low atmospheric pressure at high altitude
(d) Desert lizards lack the physiological and behavioural means to manage to their body temperature

Question- Which of the following is the most ecologically relevant environmental factor?
(a) Water
(b) Light
(c) Temperature
(d) Soil

Question-I. Conformers are the organisms that cannot maintain a constant internal environment.
II. 99% animals and nearly all plants cannot maintain their constant internal environments
III. During the course of evolution, the cost and benefits of maintaining a constant internal environment are discarded.
IV. Conformity is a condition in which an external challenge induces parallel internal changes.
V. Regulation is a condition in which external challenge elicits compensatory action to maintain the internal milien.
(a) All are correct
(b) All are wrong
(c) Only III is wrong
(d) Only IV and V are wrong

Question- The Kangaroo rat in North American desert do not drink water. How does it survive in such xeric condition.
(a) Capable of meeting all its water requirements through its internal fat oxidation
(b) Its skin is moist
(c) Hypertonic urine excretion
(d) a and c

Question- Acclimatization (compensatory mechanisms) to altitude sickness includes all except –
(a) Polycythaemia
(b) Hyperveritilation
(c) Asphyxia
(d) Decreasing binding capacity of Mb

Question- Whales, the world’s largest living mammals, live in the ocean, but there are no very smallaquatic mammals why?
(a) They get eaten by larger animals
(b) They cannot regulate body temperature effectively in water
(c) Their kidneys cannot handle life in the marine environment
(d) They lose too much heat from evaporation

Question- Basic unit of ecological hierarchy is –
(a) Ecosystem
(b) Community
(c) Population
(d) Individual

Question- Which of the following term implies the maintenance of relatively constant physical and chemical conditions within organisms?
(a) Homeostasis
(b) Adaptation
(c) Isometry
(d) Acclimation

Question- Kangaroo rats –
(a) Have a gener zed diet
(b) Avoid eating fats
(c) Do not need to drink water
(d) Are insensitive to heat

Question- The reproductive value of an individual is greatest –
(a) At birth
(b) Just before first reproduction
(c) Halfway through the reproductive stage
(d) Just before death

Question- The two sides of a given mountain have the same latitude and altitude. Are they likely to have the same climate?
(a) No, because there is likely to be less water on the side of the mountain that faces away from the prevailing wind
(b) No, because there is always on desert on one side of a mountain
(c) Yes, because latitude and altitude are the two most important climate-controlling factors
(d) Yes, because locations at the same latitude all have the same climate

Question. Match mean annual precipitation in column I with the biome in column II and choose the right option.         
     Column I             Column II
(i) 0-50 cm           A. Tropical forest
(ii) 50-100 cm       B. Coniferous forest
(iii) 150-400 cm    C. Grassland
(iv) 50-250 cm      D. Desert
(a) (i)-D (ii)-C (iii)-A (iv)-B
(b) (i)-C (ii)-A (iii)-B (iv)-D
(c) (i)-C (ii)-D (iii)-A (iv)-B
(d) (i)-B (ii)-D (iii)-A (iv)-C

Question. Organisms possessing strong and stout forelimbs with clawed digits show _______adaptations.         
(a) arboreal
(b) cursorial
(c) fossorial
(d) volant

Question. The formula of growth rate for population in given time is         
(a) dt/ dN = rN
(b) dt/rN = dN
(c) rN/dN = dt
(d) dN/dt = rN.

Question. Asymptote in a logistic growth curve is obtained when         
(a) K = N
(b) K > N
(c) K < N
(d) the value of ‘r’ approaches zero.

Question. Select the correct statement.         
(a) In a population, number of births is different from birth rate
(b) A sigmoid growth curve is depiction of exponential growth
(c) In a logistic growth curve the asymptote is beyond the carrying capacity
(d) ‘r’ is equal to the difference between number of births and number of deaths in a population.

Question. Some desert beetles can survive on “metabolic water”, without ever drinking liquid water which         
(a) is a breakdown product of pyruvate inside the mitochondria, along with carbon dioxide 
(b) was produced as water in the organisms they eat
(c) is a breakdown product from glycolysis in the cytoplasm
(d) is absorbed from the air along with respiratory oxygen.

Question. Which of the following statements regarding responses of organisms to abiotic factors is false?         
(a) All birds and mammals are capable of thermoregulation.
(b) Majority of animals and nearly all plants cannot maintain a constant internal environment.
(c) Shivering is a kind of exercise which produces heat and raises body temperature.
(d) Very small animals are commonly found in polar regions as they have to spend less energy to generate body heat.

Question. The success of mammals on earth is largely because         
(a) they have the ability to maintain constant body temperature
(b) they can conform to the changes in the environment
(c) they can take care of their young ones as they have mammary glands to suckle them
(d) they can reduce metabolic activity and go into a state of dormancy during unfavourable conditions in the environment.

Question. Which one of the following refers to Allen’s rule?         
(a) An organism can move from a stressful habitat to a more hospitable area and return when the stressful period is over.
(b) If the stressful conditions are localised or remain only for a short duration, an organism either migrates or suspends itself.
(c) Low atmospheric pressure in higher altitudes results in altitude sickness.
(d) Mammals from colder climates have shorter ears and limbs to minimize heat loss.

Question. The stage of suspended development shown by zooplanktons is called         
(a) desiccation
(b) diapause
(c) hibernation
(d) homeostasis

Assertion and Reason Based MCQs

Directions : In the following questions a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as :
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(B) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(C) Assertion (A) is true but reason (R) is false.
(D) Assertion (A) is false but reason (R) is true.

Question. Assertion (A) : Many freshwater animals cannot live for long in sea water.
Reason (R) : Freshwater animals face osmotic problems in sea water.
Answer : (A)

Question. Assertion (A) : Different habitats have different physical and chemical conditions.
Reason (R) : Physicochemical (abiotic) components characterize the habitat of an organism.
Answer : (B)

Question. Assertion (A) : A community with more species is more stable than that with less species.
Reason (R) : More the number of species, lesser the variation in the total biomass production year after year.
Answer : (A)

Question. Assertion (A) : The term interbreeding implies sexual reproduction.
Reason (R) : Interbreeding result in variation among species.
Answer : (A)

Question. Assertion (A) : Ecology is concerned with four levels of biological organisation.
Reason (R) : Organisms, populations, communities and biomes are four levels of biological organisation.
Answer : (A)

Question. Assertion (A) : Population has certain attributes which an individual organism does not have.
Reason (R) : Population is a groups of people living in well defined area, at a particular time.
Answer : (B)

Question. Assertion (A) : Natality contributes to the increase in population density.
Reason (R) : Natality refers to the number of births during a given period in the population which is added to the initial density.
Answer : (A)

Question. Assertion (A) : Small animals are rarely found in polar regions.
Reason (R) : Heat loss or heat gain is a function of surface area.
Answer : (A)

Question. Assertion (A) : Clown fish maintains a commensalistic relation with the sea anemone.
Reason (R) : In this interaction, one species benefits and the other is neither harmed nor benefited.
Answer : (A)

Question. Assertion (A) : The human population represents the logistic growth curve.
Reason (R) : When the resources are limited leading to competition between individuals and survival of fittest, the population tends to grow in a logistic manner.
Answer : (A)

We hope you liked the above provided MCQ Questions Chapter 13 Organisms and Populations Class 12 Biology with solutions. If you have any questions please ask us in the comments box below.