CLASS 12 BIOLOGY---- ORGANISMS AND POPULATION
1. A population is correctly defined as having which of the following characteristics ?
(I) Inhabiting the same general area.
(II) Individuals belonging to the same species.
(III) Possessing a constant and uniform density and dispersion.
(1) I only (2) III only (3) II and III only (4) I and II only
2. The density of a population in a given habitat during a given period, fluctuates due to changes in certain basic processes. On
this basis, fill up boxes A and B in the given flow chart with correct option :-
(1) A – Natality, B – Mortality (2) A – Immigration, B – Emigration (3) A – Natality, B – Immigration (4) Both (1) and (2)
3. Assertion : A buffalo feeds on grasses in grassland and its skin is infested with ticks. Ticks feeding birds ride on the buffalo
and feed on the ticks. During grazing this buffalo unknowingly stir up and flush out insects form the vegetation and those
insects which are flying around the buffalo they are eaten by egret birds in the vicinity. The interaction of populations
between egret birds and buffalo is commensalism.
Reason : Commensalism is the interaction in which one species benefits and other is neither harmed nor benefited.
(1) Both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
(2) Both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
(3) Assertion is True but the Reason is False.
(4) Both Assertion & Reason are False.
4. Select the true statement among followings.
(1) DFC begins with dead organic matter.
(2) DFC is the major conduit of energy in aquatic ecosystem.
(3) Some of the member of GFC become prey to the members of DFC
(4) Fungi and bacteria are not decomposers
5. An ecosystem that could be easily damage but could recover after some time if the damaging effect stops. This ecosystem
have
(1) low stability and high resilience (2) high stability and low resilience
(3) low stability and low resilience (4) high stability and high resilience
6.
In above pie chart A represents to angiosperm and D represents to fungi then C represents to -
(1) Gymnosperm (2) Algae (3) Lichen (4) Bacteria
7. Assertion : Down’s syndrome is a chromosomal disorder.
Reason : It occurs due to trisomy of chromosome no. 21.
(1) Both assertion and reason are true and reason is the correct explanation of assertion.
(2) Both assertion and reason are true and reason is not the correct explanation of assertion.
(3) Assertion is true but reason is false. (4) Both assertion and reason are false.
8. Identify the following pyramid & also identify 'a'.
(1) Pyramid of number of insects feeding on big tree. Insect = a
(2) Pyramid of biomass of insects feeding on big tree. Tree = a
1. A population is correctly defined as having which of the following characteristics ?
(I) Inhabiting the same general area.
(II) Individuals belonging to the same species.
(III) Possessing a constant and uniform density and dispersion.
(1) I only (2) III only (3) II and III only (4) I and II only
2. The density of a population in a given habitat during a given period, fluctuates due to changes in certain basic processes. On
this basis, fill up boxes A and B in the given flow chart with correct option :-
(1) A – Natality, B – Mortality (2) A – Immigration, B – Emigration (3) A – Natality, B – Immigration (4) Both (1) and (2)
3. Assertion : A buffalo feeds on grasses in grassland and its skin is infested with ticks. Ticks feeding birds ride on the buffalo
and feed on the ticks. During grazing this buffalo unknowingly stir up and flush out insects form the vegetation and those
insects which are flying around the buffalo they are eaten by egret birds in the vicinity. The interaction of populations
between egret birds and buffalo is commensalism.
Reason : Commensalism is the interaction in which one species benefits and other is neither harmed nor benefited.
(1) Both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
(2) Both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
(3) Assertion is True but the Reason is False.
(4) Both Assertion & Reason are False.
4. Select the true statement among followings.
(1) DFC begins with dead organic matter.
(2) DFC is the major conduit of energy in aquatic ecosystem.
(3) Some of the member of GFC become prey to the members of DFC
(4) Fungi and bacteria are not decomposers
5. An ecosystem that could be easily damage but could recover after some time if the damaging effect stops. This ecosystem
have
(1) low stability and high resilience (2) high stability and low resilience
(3) low stability and low resilience (4) high stability and high resilience
6.
In above pie chart A represents to angiosperm and D represents to fungi then C represents to -
(1) Gymnosperm (2) Algae (3) Lichen (4) Bacteria
7. Assertion : Down’s syndrome is a chromosomal disorder.
Reason : It occurs due to trisomy of chromosome no. 21.
(1) Both assertion and reason are true and reason is the correct explanation of assertion.
(2) Both assertion and reason are true and reason is not the correct explanation of assertion.
(3) Assertion is true but reason is false. (4) Both assertion and reason are false.
8. Identify the following pyramid & also identify 'a'.
(1) Pyramid of number of insects feeding on big tree. Insect = a
(2) Pyramid of biomass of insects feeding on big tree. Tree = a
