CBSE Class 12 Biology Organisms and Populations MCQs Set E

Question: Which of the following is not a factor that would limit the growth of a population?
a) Food shortage
b) Immigration
c) Disease
d) Weather
Answer: b

Question: Biotic potential refers to
a) Increase of population under optimum condition
b) Increase of population under given condition
c) Increase of population under natural condition
d) Increase of population under stress condition
Answer: a

Question: Population density of terrestrial organism is measured in terms of per
a) meter
b) meter²
c) meter³
d) meter⁴
Answer: a

Question: Vital index of a population is
a) (B/D) × 100
b) B – D
c) (D/B) × 100
d) B + D
Answer: a

Question: Adaptation is an attribute of organisms that enables them to survive and reproduce in their habitats. Adaptation –
a) May be morphological
b) May be physiological
c) May be behavioural
d) All
Answer: d

Question: If most individuals in a population are young, why is the population likely to grow rapidly in the future?
a) Many individuals will begin to reproduce soon
b) Death rates will be low
c) Immigration and emigration can be ignored
d) The population has a skewed age distribution
Answer: a

Question: Keolado National Park (Bharatpur) hosts thousands of migrating birds from Siberia and other extremely cold northern regions. This park is located in
a) Gujrat
b) West Bengal
c) Rajasthan
d) Madhya Pradesh
Answer: c

Question: Assuming that an animal generates heat at a rate proportional to its volume and can radiate heat at a rate proportional to its body surface area. Which of the following would be best at maintaining its body temperature in a cold climate?
a) Mouse
b) Rabbit
c) Bear
d) Fox
Answer: c

Question: A population of 100 individuals has a doubling time of 25 years. What size will this population be in 100 years?
a) 100
b) 400
c) 1600
d) 3200
Answer: c

Question: If in a pond there are 20 lotus last year and through reproduction 8 new plants are added, taking current population to 28, the birth rate per year is
a) 0.4
b) 0.8
c) 2.8
d) 0.28
Answer: a

Question: Total number of individuals of a specific species in an area is called
a) Population size
b) Population density
c) Demography
d) Population dynamics
Answer: a

Question: Organisms with very high intrinsic growth rates have
a) Long generation time
b) Short generation time
c) No carrying capacity
d) No courtship behaviours
Answer: b

Question: Parameters related to age structure include
a) Fecundity (birth rate)
b) Generation time
c) Death rate
d) All
Answer: d

Question: The age distribution of a population is determined by
a) Timing of birth
b) Timing of death
c) The rate at which the population is growing
d) All
Answer: b

Question: What four factors define population growth?
a) Births, deaths, immigration, emigration
b) Survivorship, age-specific mortality, fecundity, death rate
c) Mark-recapture, census, quadrate sampling, transects
d) Age-specific birth rate, metapopulation structure, quadrate, ecotone
Answer: a

Question: As the number of individuals approaches the carrying capacity of a population, which of the following is predicted by the sigmoidal growth curve?
a) Population biomass will remain the same
b) Population density will increase exponentially
c) Population growth rate will decrease
d) Population growth rate will increase
Answer: c

Question: In an area, there are 200 Parthenium and a single huge banyan tree. Which of the following conclusions is correct?
a) Population density of banyan is low relative to that of Parthenium
b) Population cover area of banyan is high relative to Parthenium
c) % cover or biomass is a more meaningful measure of population size
d) All the above
Answer: d

Question: Symptoms of altitude sickness include all except
a) Nausea
b) Fatigue
c) Heart palpitations
d) Hyperoxia
Answer: d

Question: Which of the following is an important adaptation of animals to cold climate
a) Thin layer of body fat
b) Aestivation
c) Increased tendency to shiver
d) Reduced surface area to volume ratio
Answer: d

Question: Which of the following is correct?
a) Natality under actual conditions is called ecological natality
b) Ability of an environment to support a population is called carrying capacity
c) Plants are killed by frost in winter because of desiccation and mechanical damage
d) All
Answer: d

Question: Which one is true?
a) Herbivores and plants appear to be more adversely affected by competition than carnivores
b) Carnivores are more adversely affected by competition than herbivores and plants
c) Both are equally affected
d) No relation can be established
Answer: a

Question: A population grows rapidly at first and then levels off at carrying capacity if it is –
a) Relatively unaffected by limiting factors
b) Limited by density independent factors
c) An opportunistic species
d) Limited by density dependent factors
Answer: a

Question: What is the fate of a population that is dominated by younger individuals and lacking older individuals?
a) Growing
b) Declining
c) Becomes highly dynamic
d) Unpredictable
Answer: a

Question: Which of the following is true for the carrying capacity (K)?
a) When N = K, the birth rate in a population is zero
b) The rate of population growth in an unlimited environment is proportional to K
c) K is always determined by the amount of food in an environment
d) In a population at its K, the birth rate equals the death rate
Answer: d

Question: Allen’s rule is related to –
a) Hibernation
b) Aestivation
c) Migration
d) Evolution
Answer: d

Question: Which of the following can be a limit on population growth?
a) Food and water
b) Space
c) Accumulated wastes
d) All
Answer: d

Question: Choose the odd one out with respect to parasitism –
a) Parasites show adaptations like loss of digestive system and high reproductive capacity
b) Parasites may reduce the survival, growth, and reproduction of the host
c) Life cycles of ectoparasites are more complex
d) Brood parasitism is seen in birds
Answer: c

Question: The logistic population growth model, dN/dt = rN (K-N/K), describes a population’s growth when an upper limit to growth is assumed. This upper limit to growth is known as the population’s ________, and as N gets larger, dN/dt _______ .
a) Biotic potential, increases
b) Biotic potential, decreases
c) Carrying capacity, increases
d) Carrying capacity, decreases
Answer: d

Question: Periodic departure and return is known as –
a) Migration
b) Immigration
c) Emigration
d) Mutation
Answer: a

Question: Exponential growth occurs when there is –
a) Asexual reproduction only
b) Sexual reproduction only
c) No inhibition from crowding
d) A fixed carrying capacity
Answer: c