NEET Biology Organisms and Populations MCQs Set 11

Answer: (c) Sharing of one or more resources between the two species

Explanation:
1. Niche overlap indicated sharing of one/more resources between the two species.
2. Hence option (c) is correct: Sharing of one or more resources between the two species

Teacher's Note:
1. Niche overlap means two species share one or more resources.
2. It leads to competition.

Answer: (c) Salamander

Explanation:
1. Salmon, Siberian crane and Arctic tern make annual migrations.
2. Salamander does not, so it is the answer.
3. Hence option (c) is correct: Salamander

Teacher's Note:
1. Salmon, Siberian crane and Arctic tern migrate every year.
2. Salamander does not migrate annually.

Answer: (d) dN/dt = rN

Explanation:
1. Exponential population growth is dN/dt = rN.
2. Hence option (d) is correct: dN/dt = rN

Teacher's Note:
1. Exponential growth is dN/dt = rN.
2. Logistic growth has an extra (K minus N)/K term.

Answer: (a) Habitat and specific functions of a species

Explanation:
1. Niche includes habitat and specific functions of species.
2. Hence option (a) is correct: Habitat and specific functions of a species

Teacher's Note:
1. A niche is the habitat plus the functional role of the species.
2. So it is more than just the place where it lives.

Answer: (c) Desert

Explanation:
1. The diurnal temperature of the soil surface varies most in deserts, because of clear skies and no vegetation cover.
2. Hence option (c) is correct: Desert

Teacher's Note:
1. Desert soil surface heats and cools quickly because there is little cover.
2. So the diurnal temperature changes most there.

Answer: (d) Thorn forests

Explanation:
1. Prosopis, Acacia and Capparis are tropical thorn forests.
2. Hence option (d) is correct: Thorn forests

Teacher's Note:
1. Prosopis, Acacia and Capparis are thorny plants of dry regions.
2. They form tropical thorn forests.

Answer: (d) Sediment characteristics of aquatic ecosystems

Explanation:
1. Benthic organisms found at the bottom of water bodies which are effected by sediment i.e. characteristics of aquatic ecosystem.
2. Hence option (d) is correct: Sediment characteristics of aquatic ecosystems

Teacher's Note:
1. Benthic organisms live at the bottom of a water body.
2. The nature of the sediment affects them most.

Answer: (d) Loss of reproductive capacity

Explanation:
1. Loss of reproductive capacity is not feature of parasitic mode of adaptation.
2. Hence option (d) is correct: Loss of reproductive capacity

Teacher's Note:
1. Parasites often lose sense organs and digestive organs and develop hooks or suckers.
2. They have very high reproductive capacity, not a loss of it.

Answer: (b) Sea

Explanation:
1. The littoral zone is the shallow area along a sea shore, exposed to wave action and very productive.
2. Hence option (b) is correct: Sea

Teacher's Note:
1. The littoral zone is the shore region, exposed to waves and highly productive.
2. In ecology it is along the sea or the edge of a lake.

Answer: (c) Lag phase – acceleration – deceleration – asymptote

Explanation:
1. A population growing in a habitat with limited resources shows four phases of growth as Lag phase – acceleration – deceleration – asymptote
2. Hence option (c) is correct: Lag phase – acceleration – deceleration – asymptote

Teacher's Note:
1. In limited resources the growth phases are lag, acceleration, deceleration and asymptote.
2. This forms the S-shaped curve.

Answer: (a) Camouflage

Explanation:
1. Praying mantis is a good example of camouflage or cryptic colouration.
2. Hence option (a) is correct: Camouflage

Teacher's Note:
1. A praying mantis resembles a leaf or a twig.
2. This is camouflage or cryptic colouration.

Answer: (a) A species which makes up only a small proportion of the total biomass of a community, yet has a huge impact on the community’s organization and survival

Explanation:
1. A species which makes up only a small proportion of the total biomass of a community, yet has a huge impact on the community organization and survival is called keystone species.
2. Hence option (a) is correct: A species which makes up only a small proportion of the total biomass of a community, yet has a huge impact on the community’s organization and survival

Teacher's Note:
1. A keystone species is small in biomass but has a big effect on the community.
2. Its loss can change the whole community.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. All environmental factors are limited by time and space.
2. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. The holistic approach is true, but environmental factors are limited by time and space.
2. So the Reason is false.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Regulators maintain their internal conditions by homeostasis.
2. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. Regulators keep their internal conditions constant by homeostasis, but only up to a limit.
2. The Reason is false in the form given in the book.

Answer: (a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Explanation:
1. Basic unit of evolution is population.
2. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. Natural selection acts on the population and so links ecology with genetics and evolution.
2. The population is the basic unit of evolution.

Answer: (a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Explanation:
1. Exponential growth occurs when unlimited resources are available.
2. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. With unlimited resources a population grows exponentially.
2. Resources are never unlimited for long, but both statements fit the exponential model.

Answer: (a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Explanation:
1. Ficus species are pollinated by wasp- Blastophaga.
2. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. Fig species and wasps have a tight one-to-one partnership.
2. It is an example of co-evolution of plants and insects.

Answer: (a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Explanation:
1. Closely related species can survive in same habitat and avoid competition by resource partitioning.
2. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. Resource partitioning lets related species coexist.
2. Foraging differences in warblers are an example.

Answer: (b) Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Explanation:
1. Sudden decrease in population is crash phase.
2. Hence option (b) is correct: Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Teacher's Note:
1. Environmental resistance slows exponential growth in logistic growth.
2. There is no crash phase in the logistic curve, but this does not explain the Assertion.

Answer: (a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Explanation:
1. Ecotypes are genetically adapted populations.
2. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. Ecotypes are genetically different local forms of one species that can still interbreed.
2. They arise through local natural selection.