CBSE Class 12 Biology Organisms and Populations VBQs

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
Answer : D

Question. Which of the following is correct for r-selected species?
(a) Large number of progeny with small size
(b) Large number of progeny with large size
(c) Small number of progeny with small size
(d) Small number of progeny with large size
Answer : A

Question. Lichen is an example of
(a) parasitism
(b) predation
(c) commensailism
(d) mutualism
Answer : D

Question. Lichens represent an intimate mutualistic relationship between
(a) fungus and bacteria
(b) fungus and photosynthetic algae
(c) fungus and archaebacteria
(d) fungus and plants
Answer : B

Question. Mycorrhiza represents an intimate mutualistic relationship between
(a) fungi and stem of higher plants
(b) fungi and roots of higher plants
(c) fungi and leaves of higher plants
(d) fungi and leaflets of higher plants
Answer : B

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) Banana
(b) Yucca
(c) Hydrilla
(d) Viola
Answer : B

Question. Pseudocopulation occurs in
(a) maize
(b) Ophrys
(c) mango
(d) papaya
Answer : B

Question. The plant-animal interaction often involve coevolution of the mutualists, so that
(a) the mutually beneficial system could be safeguarded against cheaters
(b) a given plant species can be pollinated only by its partner animal species and no other species
(c) the animal utilises plant not only for oviposition but also to pollinate the plant
(d) All of the above
Answer : D

Question. The interdependent evolution of the flowering plants and pollinating insects together is known as
(a) mutualism
(b) coevolution
(c) commensalism
(d) cooperation
Answer : B

Question. In …… one species is harmed whereas the other is unaffected.
(a) predation
(b) amensalism
(c) commensalism
(d) parasitism
Answer : B

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

 Assertion and Reason
In each of the following questions, a statement of Assertion (A) is given followed by corresponding statement of Reason
(R). Of the statements, mark the correct answer as
(a) If both A and R are true and R is the correct explanation of A
(b) If both A and R are true, but R is not the correct explanation of A
(c) If A is true, but R is false
(d) If A is false, but R is true

Question. Assertion (A) Species are groups of potentially interbreeding natural populations that are isolated from other such groups.
Reason (R) Reproductive isolation brings about distinctive morphological characters.
Answer : C

Question. Assertion (A) Ecological equivalents possess similar types of adaptations.
Reason (R) Ecological niche is the total interaction of a species with environment.
Answer : B

Question. Assertion (A) Biotic community has higher position than the population in ecological hierarchy.
Reason (R) Population of similar individuals remain isolated in the community.
Answer : C

Question. Assertion (A) Predation is an interspecific interaction with a feeding strategy.
Reason (R) Predators and their prey maintain fairly stable population through time and rarely one population become abundant or scarce.
Answer : A

Question. Assertion (A) The prickly pear cactus introduced into Australia in early 1920s caused havoc by spreading rapidly into millions of hectares of rangeland.
Reason (R) When certain exotic species are introduced into a geographical area, they become invasive and start spreading first because the invaded land does not have its natural predators.
Answer : A

Question. Assertion (A) In commensalism, one organism is benefitted and other is unaffected.
Reason (R) Cattle egret bird and cattle is an example of commensalism.
Answer : B

Question. Assertion (A) Plants need the help of insects and animals for pollinating their flowers and dispersing their seeds.
Reason (R) Plants offer rewards in the form of pollen and nectar for pollinators and juicy and nutritious fruits for seed dispersers.
Answer : B

Question. Assertion (A) Living organisms are considered closed systems.
Reason (R) Living organisms exchange energy and materials with the environment.
Answer : D

Question. Assertion (A) In tropical rainforests, O-horizon and A-horizon of soil profile are shallow an nutrient poor.
Reason (R) Excessive growth of microorganisms in the soil deplete its organic content.
Answer : C

Question. Assertion (A) A mangrove tree growing in marshy place does not have pneumatophores.
Reason (R) Pneumatophores help in taking in air from atmosphere deficient saline soil.
Answer : D

Statement Based Questions

Question. Read the following statements.
I. The levels of thermal tolerance of different species determinate a large extent their geographical distribution.
II. Life on earth originated in water and is unsustainable without water.
III. The salt concentrations (measused or salinity in parts pre thousand) is less than 5 in inland waters, 30-35 in the sea and > 100 in some hypersaline lagoons.
IV. Many animals use the diurnal and seasonal variations in light intensity and duration as cues for timing their foraging, reproductive and migratory activities.

Which of the given above statements are correct?
(a) I, II and III
(b) II, III and IV
(c) I, III and IV
(d) I, II, III and IV
Answer : D

Question. Consider the following statements about regulation in humans.
I. In summer,we sweat profusely causing evaporative cooling brings down the body temperature.
II. In winters, we shiver which is an exercise that
produces heat and raises the body temperature.
Choose the correct option.
(a) Statement I is true, but II is false
(b) Statement II is true, but I is false
(c) Both statements are true
(d) Both statements are false
Answer : C

Question. Read the following statements and choose the correct statement.
(a) Species ability to adapt is over a limited range of environment
(b) If stressful external conditions are localised or remain only for a short duration the organism regulate for survival
(c) Migration is moving away permanently from the stressful habitat to more hospitable area and return when stressful period is over
(d) All of the above
Answer : B

Question. I. Desert lizard bask in the sun and absorbs heat when their body temperature drops below the comfort zone, but move into shade when the ambient temperature starts increasing.
II. Somespecies like rabbits and ground hog are capable of burrowing into the soil to hide and escape from the above ground heat.
Above statements are the examples of
(a) cursorial adaptation
(b) behavioural adaptation
(c) fossorial adaptation
(d) scansorial adaptation
Answer : B

Question. I. Many xerophytic plants have thick cuticle on leaf epidermis and sunken stomata.
II. Somexerophytic plants have special photosynthetic pathway (CAM) that enables their stomata close during day.
III. Opuntia has spines (modified leaves), photosynthetic phylloclade (stem).
IV. Adaptations are genetically fixed in organisms.
Choose the correct statements.
(a) I, II, III and IV (b) II, III and IV
(c) III, IV, and I (d) I, II and III
Answer : A

Question. Consider the following statements.
I. The number of individuals of the same species that have come into the habitat from elsewhere during the time period under consideration is called emigration.
II. The number of individuals of the population who left the habitat and gone elsewhere during the time period under consideration is called immigration.
Choose the correct option.
(a) Statement I is true and II is false
(b) Statement I is false and II is true
(c) Both the statements are true
(d) Both the statements are false
Answer : D

Question. Read the following statements.
I. Any species growing exponentially under unlimited resource condition can reach enormous population densities in short time.
II. Darwin showed how even a slow growing animal like element could reach enormous numbers in the absence of check.
III. If there are non-limiting or unlimited conditions are provided then natality and mortality decrease within a population.
Choose the correct option.
(a) Statements I and II are correct
(b) Statements I and III are correct
(c) Statements II and III are incorrect
(d) All statements are incorrect
Answer : A

Question. Read the following statements.
I. In a population, birth rate and death rate refer to per capita births and deaths, respectively.
II. In nature, we rarely find isolated single individuals of any species.
III. The size of population for any species is stable phenomena.
IV. Ecological effects of any factors on a population growth are generally reflected in its size/population density.
Choose the correct statements.
(a) I and II
(b) II and III
(c) I, II and III
(d) I, II and IV
Answer : D

Question. Read the following statements and choose the correct one.
(a) A is a triangular age pyramid, where pre-reproductive stage is very large as compared to the reproductive and post-reproductive stages of the population. This type of
age structure indicates that the population would increase rapidly
(b) B is an inverted bell-shaped age pyramid where number of pre-reproductive and reproductive individuals is almost equal. This type of age structure indicates that the population is stable
(c) C is an urn-shaped age pyramid where more number of reproductive individuals are present. This type of age structure indicates that the population is declining
(d) All of the above
Answer : D

Question. For a situation when food and space for a population are unlimited, which of the following statements given below represent incorrect features?
I. Each species has the ability to realise fully its inherited potential to grow.
II. Then, it is equal to dN /dt = rN.
III. It is described by J-shaped curve.
IV. It is described by S-shaped curve.
V. That it has greater intrinsic rate for resources.
VI. There are more competition among themself.
(a) I, II and III
(b) II, III and IV
(c) IV and VI
(d) IV, V and VI
Answer : C

Question. Which one is the correct statement for logistic model of population growth?
I. Population growth rate increases as the size of population approaches the carrying capacity.
II. All individuals have same effect on population growth.
III. There are unlimited natural resources.
IV. As population increases the competition goes on increasing.
(a) I and II
(b) Only IV
(c) IV and III
(d) I and III
Answer : B

Question. In an area, there are 200 Parthenium and a single banyan tree. For the information given above which of the following conclusive statement(s) is/are correct?
I. Population density of banyan is high.
II. Population cover area of banyan is high.
III. In above case, the percentage of cover area or biomass is more meaningful than population size.
(a) Only I
(b) I and II
(c) II and III
(d) I, II and III
Answer : C

Question. I. Populations evolve to maximise their reproductive fitness, also called Darwinian fitness (higher r value), in the habitat in which they live.
II. The population growth rate r is inversely related to generation time.
III. The housefly, which has a short lifespan and produces a large number of eggs, could be considered as a ‘K’ selected species.
IV. Under a particular set of selection pressures, organisms evolve towards the most efficient reproductive strategies.
V. Life history traits of organisms have evolved in relation to the constraints imposed by biotic and abiotic factors in their habitat.
Select the correct option from the statements given above.
(a) I, II and III
(b) I, III and IV
(c) III, IV and V
(d) All except III
Answer : D

Question. Consider the following statements.
I. Brood parasitism in birds is an example of parasitism in which the parasitic bird lays its eggs in the nest of its host and host incubates them.
II. During the course of evolution, the eggs of the parasite bird have evolved to resemble the host’s eggs in size and colour to reduce the chances of the host bird detecting the foreign eggs and removing them from the nest.
(a) Statement I is true, but II is false
(b) Statement I is false, but II is true
(c) Both statements are true
(d) Both statements are false
Answer : C

Question. Read the following statements.
I. Parasite that feed on the external surface of the host organism.
II. Lice on humans and ticks on dogs.
III. Marine fish infested with copepods.
IV. Cuscuta growing on hedge plant.
V. Parasite that lives inside the host body at different sites to derive benefit.
VI. Liver fluke living inside the animal body.
Answer : B

Question. Read the following statements about ‘recent studies supporting competition’ as suggested in ‘Gause’s competitive exclusion principle’.
I. Gause’s hypothesis says if two species compete for same resources then one will be eliminated by another species.
II. More recent studies point out that species facing competition might evolve mechanisms that promote coexistence rather than exclusion.
III. Gause’s competitive exclusion principle is effective when resources are in excess.
IV. Unlimited resources give better opportunity for adaptation.
Choose the correct combination of statements.
(a) I and II
(b) I, II and IV
(c) III and IV
(d) I and IV
Answer : A

Question. I. The human liverfluke, a nematode parasite, depends on two intermediate hosts (snail and fish) to complete its life cycle.
II. The malaria parasite needs a vector (mosquito) to spread to other hosts.
III. The female mosquito is not considered parasite, however it needs our blood for reproduction.
IV. In case of brood parasitism, the eggs of parasitic birds (e.g. cuckoo) are not detected and ejected from the nest because of parasite’s eggs resemble the hosts eggs in
morphology and colour.
V. Apopulation of frogs protected from all predators would increase indefinitely with unlimited food resources.
Which statements are correct?
(a) I and II
(b) II and III
(c) III, IV and V
(d) I, II, III and IV
Answer : D

Question. Which of the following statements are incorrect?
(a) Host is an organism which provides food and shelter to another organism
(b) Amensalism is a relationship in which one species is benefitted, whereas the other is unaffected
(c) Predator is an organism that catches and kills other organism for food
(d) Parasite is an organism which always lives inside or on the body of other organism and may kill it
Answer : B

Question. Which of the following statements regarding species interdependence are true?
(a) An association of two species where one is benefitted and other remains unaffected is called mutualism 
(b) An interspecific association where both partners derive benefit from each other is called commensalism 
(c) Adirect food relation between two species of animals in which one animal kills and feeds on another is referred as parasitism
(d) Arelationship between two organisms of different species where both the organisms are benefitted from each other is called symbiosis
Answer : D

Question. Choose the incorrect statement.
(a) Mutualistic relationships evolve when benefit of both species out weights the costs
(b) Mutualistic relationship evolves when benefits of both species under weight the costs
(c) Humans cause ecological imbalance by eradicating common parasites
(d) Humans cause altering competition between species
Answer : B

Question. Choose the incorrect statement.
(a) Parasite might render the host more vulnerable to predation by making it physically weak
(b) Majority of the parasites harm the host and reduce the population density
(c) Ideal parasite should be able to thrive within hostwi thout harming it
(d) Malarial parasite does not need a vector (mosquito) to spread to other host
Answer : D

Question. Choose the incorrect statement.
(a) Two closely related species may not live in same habitat
(b) The more dissimilar the niches of two species the stronger is their competition
(c) Two species cannot occupy the same niche in geographical area
(d) Two species may occupy the same ecosystem
Answer : B

Question. Which of the following is correct?
(a) Logistic growth model is more realistic than exponential growth model
(b) r-selected species have low fecundity, large body size and late maturity
(c) K-selected species have high fecundity, small body size and early maturity
(d) Altruistic behaviour is common in dogs
Answer : A

Question. Hibernation is shown by
(a) frog
(b) rabbit
(c) earthworm
(d) None of the above
Answer : A

Question. The cause of death of marine fish kept in freshwater aquarium is
(a) marine fish does not live in freshwater
(b) endosmosis will occur and it will swell
(c) Both (a) and (b)
(d) None of the above
Answer : B

Question. Which one of the following is incorrect?
(a) Eutrophic lakes are rich in nutrient and has high biological productivity
(b) Animals do not respond to photoperiods, but plants do so 
(c) Oligotrophic lakes are poor in nutrients, clear and with low biological productivity
(d) Mesotrophic lakes have properties in between eutrophic and oligotrophic lakes
Answer : B

Question. Which of the following is correct?
(a) Antarctic fishes can survive below O°C as these have antifreeze solutes in their body
(b) Archaebacteria can flourish in hot springs and deep sea hydrothermal vents where temperature is above 100°C
(c) Desert lizard lacks the physiological ability to cope with extreme temperature, but manage the body temperature by behavioural means
(d) All of the above
Answer : D

Question. Which of the following is correct?
(a) Parasites do not tend to coevolve with the host
(b) ‘Brood parasitism’ is absent in cuckoo
(c) In general, herbivores and plants appear to be more adversely affected by competition than carnivores
(d) The life cycle of parasites is often very simple involving one intermediate host or vector
Answer : C

Question. Choose the correct statement.
(a) Among the red, green and brown algae, the red algae are found in the deepest ocean
(b) Animals restricted to a narrow range of salinity are euryhaline
(c) Every winter, the famous Keoladeo National Park (Odisha) hosts thousands of migratory birds
(d) The mammals of colder climates generally have longer extremities to minimise heat loss
Answer : A

Question. An adaptation in Opuntia is that, it performs photosynthesis by
(a) flower
(b) stem
(c) roots
(d) shoot
Answer : B

Question. ……… rule states that mammals from colder climates generally have shorter ears and limbs to minimise heat loss.
(a) Allen’s rule
(b) Bergmann‘s rule
(c) Rensch’s rule
(d) Jordan‘s rule
Answer : A

Question. How seals can survive in polar climate where the temperature prevails below 0°C?
(a) They have long hairs on their body surface
(b) They have thick layer of fat below their skin
(c) Both (a) and (b)
(d) They have genetic regulation for avoiding cold climate
Answer : B

Question. Altitude sickness occurs at high mountains. Thissickness h ave symptoms like
(a) nausea
(b) fatigue
(c) heart palpitations
(d) All of these
Answer : D

Question. At high altitude, we feel sick and nauseated. The reason for this sickness may be
(a) low atmospheric pressure
(b) high atmospheric pressure
(c) high temperature
(d) low temperature
Answer : A

Question. Body compensates for low oxygen availability at due to the altitudes sickness by
(a) increasing RBC
(b) decreasing binding affinity of haemoglobin
(c) increasing breathing rate
(d) All of the above
Answer : D

Question. In most animals, the metabolic reactions proceed in a...A ... temperature range (in humans, it is 37°C). But there are microbes (archaebacteria) that flourish in hot springs and deep sea hydrothermal vents where temperatures far exceed ...B... .
Choose the correct option for A and B.
(a) A–narrow, B–100°C
(b) A–broad, B–100°C
(c) A–median, B–100°C
(d) A–broad, B–40°C
Answer : A

Question. Which of the following problems does the frequentdee p sea diving organisms like whales may face?
(a) Compression of tissues surrounding air-filled cavities 
(b) High blood nitrogen levels
(c) Lack of oxygen
(d) All of the above
Answer : D

Question. Whales can resist tissue compression during deep sea diving because they have
(a) special proteins that prevent air absorption
(b) extensive blood vasculature which swells up to reduce the size of air-filled cavities
(c) thick coat of fat around body that works as an insulator
(d) None of the above
Answer : B

Question. Desert lizards lack the ...A... ability that mammals have to deal with the ...B... temperatures of their habitat, but manage to keep their body temperature fairly constant by ...C... means.
Choose the correct option for A, B and C.
(a) A–morphological, B–high, C–behavioural
(b) A–physiological, B–high, C–behavioural
(c) A–behavioural, B–high, C–physiological
(d) A–physiological, B–high, C–morphological
Answer : B

Question. Population is the total number of
(a) interbreeding individuals of a species found in a geographical area
(b) interbreeding individuals of a species found in different geographical area
(c) Both (a) and (b)
(d) None of the above
Answer : A

Question. If in a pond, there are 20 lotus plants of last year and through reproduction 8 new plants are added. Then, the birth rate is
(a) 0.8 offspring per lotus per year
(b) 0.2 offspring per lotus per year
(c) 0.4 offspring per lotus per year
(d) 0.6 offspring per lotus per year
Answer : C

Question. Individuals alive at the beginning of 1 year to 2 years age interval is 800. During this interval 200 individuals die. Then find out the death rate.
(a) 200
(b) 800
(c) 0.4
(d) 0.25
Answer : D

Question. Sex ratio is the
(a) ratio of females to males
(b) ratio of males to females
(c) Both (a) and (b)
(d) ratio of infant girl to infant boy
Answer : B

Question. If birth rate is 100, death rate is 10 and number of individuals in population group is 1000, then what will be the percentage of natural growth rate?
(a) 0.09%
(b) 9.0%
(c) 0.9%
(d) 90%
Answer : B

Question. If the age distribution is plotted for a population, the resulting structure is called as
(a) age graph
(b) age curve
(c) age pyramid
(d) age diagram
Answer : C

Question. Ecological age groups of populations are
I. Pre-reproductive
II. Reproductive
III. Post-reproductive
IV. Old-age group
V. Adolescent age group
VI. Infertile age group
Choose the correct combination.
(a) I, II and III
(b) III, IV and V
(c) IV, V and VI
(d) I, V and VI
Answer : A

Question. The age structure of a population represents
(a) relative number of individuals at each age
(b) number of newborns each year
(c) number of individuals reaching puberty each year
(d) relative number of deaths at each age
Answer : A

Question. Age structure of a population influences population growth because
(a) different age groups have different reproductive capabilities
(b) different age groups have same reproductive capabilities
(c) more young individuals indicate decreasing population
(d) All of the above
Answer : A

Question. Under normal conditions positive growth or rapid increase in the population is indicated by
(a) less number of young individuals
(b) large number of young individuals
(c) large number of old individuals
(d) large number of childbirth
Answer : B

Question. The age pyramid with broad base indicates
(a) high percentage of young individuals
(b) low percentage of young individuals
(c) high percentage of old individuals
(d) All of the above
Answer : A

71.............
(a) A–Expanding, B–Stable, C–Declining
(b) A–Stable, B–Expanding, C–Declining
(c) A–Stable, B–Declining, C–Expanding
(d) A–Declining, B–Stable, C–Expanding
Answer : A

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

Question. Bell-shaped age pyramid indicates that
(a) number of pre-reproductive and reproductive individual is almost equal
(b) post-reproductive individuals are comparatively fewer
(c) the population size remains stable
(d) All of the above
Answer : D

Question. Zero growth of population is indicated by
(a) less number of childbirth
(b) less number of reproductive females
(c) reproductive individuals are equal to pre-reproductive individuals
(d) less number of males than females
Answer : C

Question. When there is a large number of post-reproductive or older individuals and lesser number of prereproductive individuals then that population is
(a) growing
(b) declining
(c) stable
(d) None of these
Answer : B

Question. Population size is more technically called
(a) population density
(b) demography
(c) population growth
(d) population dynamics
Answer : A

Question. In some cases, population density is measured in terms of biomass rather than in terms of number because
(a) it is more meaningful measure when the considered organisms vary greatly in size
(b) it is more convenient when population is huge and counting is impossible or very time consuming
(c) it is relatively constant measure
(d) Both (a) and (b)
Answer : D

Question. Which of the following is not an example of using relative density to measure population density in a certain area?
(a) Counting pugmarks of tigers to find population density of tigers in a forest
(b) Counting the number of fishes caught in a trap to find population density of fishes in a lake
(c) Measuring biomass of bacterial culture to find out population density of bacteria in a petri dish
(d) Both (a) and (c)
Answer : D

Question. For which of the following cases, population density can be easily determined by utilising non-biological parameter?
(a) Fish density
(b) Density of bacteria in culture plate
(c) Siberian cranes in Bharatpur wetlands
(d) Tiger census
Answer : D

Question. Population of any species is
(a) a static phenomena
(b) a dynamic phenomena
(c) Neither (a) nor (b)
(d) Both (a) and (b)
Answer : B

Question. Population density of a population in a given habitat during a given period fluctuates due to the change in
(a) natality and mortality
(b) immigration
(c) emigration
(d) All of these
Answer : D

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

Question. A biologist studied the population of rats in a barn.He found that the average natality was 250, average mortality 240, immigration 20 and emigration 30.
The net increase in population is
(a) 10
(b) 15
(c) 05
(d) zero
Answer : D

Question. Study the figure and identify A to D. (Image 84)
(a) A–Increase, B–Decrease, C–Increase, D–Decrease
(b) A–Decrease, B–Increase, C–Decrease, D–Increase
(c) A–Increase, B–Increase, C–Decrease, D–Decrease
(d) A–Decrease, B–Decrease, C–Increase, D–Increase
Answer : C

Question. A ¾® ¬¾¾ Å Population density O− B.
If A increases population density and B decreases it then choose the correct option of A and B.
(a) A can be mortality which brings positive change in population density
(b) B can be emigration which brings negative change in population density
(c) values of A and B can never be equal
(d) Both (b) and (c)
Answer : D

Question. If natality is represented by –B
If mortality is represented by –D
If immigration is represented by –I
If emigration is represented by –E
If population density is represented by –N
Then, population density at time t+1 is represented by
(a) Nt + 1 = Nt – [(B + I) – (D + E)]
(b) Nt + 1 = Nt + [(B + I) – (D + E)]
(c) Nt + 1= Nt + [(B + I) + (D + E)]
(d) Nt + 1 = Nt – [(B + I) + (D + E)]
Answer : B

Question. Under normal condition, ...A... and ...B... are the most important factors influencing population density, ...C... and ...D... assuming importance only under special condition.
Choose the correct option for A, B, C and D.
(a) A–mortality, B–natality, C–emigration, D–immigration
(b) A–immigration, B–natality, C–emigration, D–mortality
(c) A–emigration, B–natality, C–mortality, D–immigration
(d) A–emigration, B–immigration, C–mortality, D–natality
Answer : A

Question. Ratio between natality and mortality is called
(a) population ratio
(b) vital index
(c) density co-efficient
(d) census ratio
Answer : B

Question. Who stated that human population grows geometrically?
(a) Malthus
(b) Darwin
(c) Cannon
(d) Lamarck
Answer : A

Question. Geometric representation of age structure is a characteristic of
(a) biotic community
(b) population
(c) landscape
(d) ecosystem
Answer : B

Question. Exponential growth occurs when
(a) there is only sexual reproduction
(b) there is only asexual reproduction
(c) there is a fixed carrying capacity
(d) no inhibition from crowding
Answer : D

Question. If b represents® Birth rate
If d represents® Death rate 
If dN represents® Increase or Decrease in population size
Then, exponential growth is represented by
(a) dN/dt = (b + d) × N
(b) dN/dt = (b − d) × N
(c) dN/dt = (d − b) × N
(d) dN/dt = (d b )− N
Answer : B

Question. In the exponential growth equation, if b − d is represented by r, then ‘r’ may be called as
(a) intrinsic rate of natural increase
(b) extrinsic rate of natural increase
(c) morphological rate of natural increase
(d) phenotypical rate of natural increase
Answer : A

Question. Population A–has the intrinsic rate of natural increase is 0.2.
Population B–has the intrinsic rate of natural increase is 0.3.
Population C–has the intrinsic rate of natural increase is 0.4.
Population D–has the intrinsic rate of natural increase is 0.5.
Which population will increase fastest among all of the given population?
(a) D
(b) C
(c) B
(d) A
Answer : A

Question. Below diagram indicates (Image 95)
(a) exponential growth curve
(b) logistic growth pattern
(c) J-shaped curve
(d) Both (a) and (c)
Answer : D

Question. No population of any species in nature has at its disposal …A… resources to permit exponential growth. This leads to competition between individuals for …B… resources. Eventually, the …C… individual will survive and reproduce.
Choose the correct option for A, B and C.
(a) A–limited, B–limited, C–fittest
(b) A–limited, B–unlimited, C–fittest
(c) A–unlimited, B–limited, C–fittest
(d) A–unlimited, B–unlimited, C–fittest
Answer : C

Question. Carrying capacity is the capacity of
(a) habitat that has resources to sustain certain number of individuals
(b) population to reproduce and competitiveness
(c) population to reproduce
(d) individuals to fit among the natural environment
Answer : A

Question. Logistic growth occurs when there is
(a) no resistance from increasing population
(b) unlimited food
(c) fixed carrying capacity
(d) All of the above
Answer : C

Question. Which of the following is true regarding exponential growth?
(a) No population can grow exponentially for long
(b) Exponential growth slows down as the population nears its log phase
(c) Bacterial colonies have been observed to maintain exponential growth always
(d) Exponential growth is a commonly observed in large, slow-growing species such as humans and elephants
Answer : A

Question. Given population growth curve represents the logistic growth curve. In this curve, find out what do A, B and C indicate.  (Image 101)
(a) A–Lag phase, B–Log phase, C–Stationary phase
(b) A–Log phase, B–Lag phase, C–Stationary phase
(c) A–Stationary phase, B–Log phase, C–Lag phase
(d) A–Stationary phase, B–Lag phase, C–Log phase
Answer : C