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

Find here the NCERT chapter-wise Multiple Choice Questions from Class 12 Biology book Chapter 13 Organisms and Populations with Answers Pdf free download. This may assist you to understand and check your knowledge about the chapters. Students also can take a free test of the Multiple Choice Questions of Organisms and Populations. Each question has four options followed by the right answer. These MCQ Questions are selected supported by the newest exam pattern as announced by CBSE.

NCERT MCQ Chapters for Class 12 Biology

Q1. Two different species cannot live for long duration in the same niche or habitat. This law is called

(i) Allen’s law
(ii) Glogerrule
(iii) Competitive exclusion principle
(iv) Weisman’s theory.

Above

Q2. In a population, unrestricted reproductive capacity is called

(i) Biotic potential
(ii) Birth rate
(iii) Fertility
(iv) Carrying capacity

(i) Biotic potential

Q3. According to Allen’s Rule, the mammals from colder climates have:

(i) shorter ears and longer limbs
(ii) longer ears and shorter limbs
(iii) longer ears and longer limbs
(iv) shorter ears and shorter limbs.

(iv) shorter ears and shorter limbs.

Q4. The interspecific interaction in which one partner is benefitted and the other is unaffected (neutral), is called

(i) amensalism
(ii) mutualism
(iii) competition
(iv) commensalism

(iv) commensalism

Q5. Competitive exclusion principle stating that inferior species is eliminated eventually after prolonged competition was given by

(i) Allen
(ii) Pearl-Verhulst
(iii) Gause
(iv) Darwin.

(iv) Darwin.

Q6. When the number of immigration and births is more than emigration and deaths, the growth curve of the population will show

(i) Declining phase
(ii) Steady phase
(iii) Exponential phase
(iv) Lag phase

(iii) Exponential phase

Q7. Ecological niche is:

(i) the surface area of the ocean
(ii) a an ecologically adapted zone
(iii) the physical position and functional role of a species within the community
(iv) formed of all plants and animals living at the bottom of a lake.

(iii) the physical position and functional role of a species within the community

Q8. Mycorrhiza is an example of

(i) ectoparasitism
(ii) mutualism
(iii) endoparasitism
(iv) predation

(ii) mutualism

Q9. Which of the following is not an example of preypredator relationship ?

(i) Tiger eating a deer
(ii) Plant Nepenthes trapping an insect
(iii) Bacteria decomposing organic matter
(iv) Crocodile killing a man

(iii) Bacteria decomposing organic matter

Q10. Biotic components of the ecosystem :

(i) Share and compete for resources
(ii) Only compete for resources
(iii) Only share their resources
(iv) Neither share nor compete for resources

(i) Share and compete for resources

Q11. Biosphere is:

(i) A component in the ecosystem
(ii) Composed of the plants present in the soil
(iii) Life in the outer space
(iv) Composed of all living organisms present on the earth which interact with the physical environment.

(iv) Composed of all living organisms present on the earth which interact with the physical environment.

Q12. It natality is balanced by mortality in a population at a given time, there will be a/an

(i) decrease in the population size
(ii) increase in the population size
(iii) zero population growth
(iv) population explosion

(iii) zero population growth

Q13. Why you never see cattle or goats browsing on weed Calotropis ?

(i) The plant produces highly poisonous tannins.
(ii) The plant produces quinine which is bitter in taste.
(iii) The plant produces poisonous cardiac glycosides.
(iv) The plant bears prickles.

(iii) The plant produces poisonous cardiac glycosides.

Q14. Which of the following would necessarily decrease the density of a population in a given habitat?

(i) Immigration > emigration
(ii) Natality and immigration
(iii) Natality > mortality
(iv) Mortality and emigration

(iv) Mortality and emigration

Q15. Autecology is the

(i) relation of a population to its environment
(ii) relation of an individual to its environment
(iii) relation of a community to its environment
(iv) relation of a biome to its environment.

(ii) relation of an individual to its environment

Q16. Niche is defined as

(i) a component of an ecosystem
(ii) an ecologically adapted zone of a species
(iii) the physical position and functional role of a species within the community
(iv) all plants and animals living at the bottom of a water body.

(iii) the physical position and functional role of a species within the community

Q17. The prickly pear cactus became unusually abundant after its introduction in Australia, because it

(i) had no coevolved herbivores
(ii) formed new mycorrhizal association
(iii) lost its thorns
(iv) all of these.

(i) had no coevolved herbivores

Q18. The plants of this group are adapted to live partly in water and partly above substratum and free from water

(i) Xerophytes
(ii) Thallophytes
(iii) Hydrophytes
(iv) Helophytes

(iv) Helophytes

Q19. Salt concentration (salinity) of the sea measured in parts per thousand is:

(i) 10-15
(ii) 30-70
(iii) 0-5
(iv) 30-35.

(iv) 30-35.

Q20. An interaction between two individuals where one is benefitted while the other is neither benefitted nor harmed is called as

(i) predation
(ii) symbiosis
(iii) amensalism
(iv) commensalism.

(iv) commensalism.

Q21. All of the following do not harm their host except:

(i) Pilot fish
(ii) Pediculus
(iii) Orchids
(iv) Balanus

(ii) Pediculus

Q22. Which of the following forest plants controls the light conditions at the ground?

(i) Lianas and climbers
(ii) Shrubs
(iii) Tall trees
(iv) Herbs.

(iii) Tall trees

Q23. Animals from colder climates generally have shorter limbs. This is called

(i) Allen’s rule
(ii) Johnson’s rule
(iii) Arber’s rule
(iv) Niche rule

(i) Allen’s rule

Q24. The interdependent evolution of flowering plants and pollinating insects together is known as

(i) mutualism
(ii) co-evolution
(iii) commensalism
(iv) co-operation.

(ii) co-evolution

Q25. The population growth curve is sigmoid if the growth pattern is

(i) Geometric
(ii) Accretionary
(iii) Logistic
(iv) Exponential

(iii) Logistic

Q26. If a population of 50 Paramoecium present in a pool increases to 150 after an hour, what would be the growth rate of population?

(i) 50 per hour
(ii) 200 per hour
(iii) 5 per hour
(iv) 100 per hour.

(iv) 100 per hour.

Q27. The formula of exponential population growth curve, is

(i) dN/dt = rN
(ii) dt/dN rN
(iii) dN/rN = dt
(iv) rN/dN = dt

(i) dN/dt = rN

Q28. Basic unit of ecological hierarchy is

(i) population
(ii) community
(iii) ecosystem
(iv) individual.

(iv) individual.

Q29. Which should be considered more realistic growth model?

(i) Verhulst-Pearl logistic growth
(ii) Geometric growth
(iii) Exponential growth
(iv) None of the above

(i) Verhulst-Pearl logistic growth

Q30. A population has more young individuals compared to the older individuals. What would be the status of the population after some years?

(i) It will decline.
(ii) It will stabilise.
(iii) It will increase.
(iv) It will first decline and then stabilise.

(iii) It will increase.

Q31. Niche overlap indicates

(i) mutualism between two species
(ii) active cooperation between two species
(iii) sharing of one or more resources between the two species
(iv) two different parasites on the same host.

(iii) sharing of one or more resources between the two species

Q32. Several plant and animal species present together at a place constitute a

(i) genus
(ii) population
(iii) biome
(iv) community.

(iv) community.

(i) number of males
(ii) number of females
(iii) both (i) and (ii)
(iv) none of these

(ii) number of females

Q34. What parameters are used for tiger census in our country’s national parks and sanctuaries?

(i) Pugmarks only
(ii) Pug marks and faecal pellets
(iii) Faecal pellets only
(iv) Actual head counts.

(ii) Pug marks and faecal pellets

Q35. Which of the following would necessarily decrease the density of a population in a given habitat?

(i) Natality > mortality
(ii) Immigration > emigration
(iii) Mortality and emigration
(iv) Natality and immigration

(iii) Mortality and emigration

Q36. Characteristics of a terrestrical biome are strongly influenced by its

(i) flora
(ii) climate
(iii) fauna
(iv) all of these.

(ii) climate

Q37. The rate of individuals born per 1,000 individuals per year is called

(i) Mortality rate
(ii) Growth rate
(iii) Vital rate
(iv) Natality rate

(iv) Natality rate

Q38. A protozoan reproduces by binary fission. What will be the number of protozoans in its population after six generations?

(i) 128
(ii) 24
(iii) 64
(iv) 32.

(iii) 64

Q39. What parameters are used for tiger census in our country’s national parks and sanctuaries ?

(i) Pug marks only
(ii) Pug marks and faecal pellets
(iii) Faecal pellets only
(iv) Actual head counts