Ecology Assertion Reason Based Questions

Part 1

The following questions consist of two statements, one labelled as Assertion (A) and the other labelled the Reason ®. Examine these two statements carefully and select the most appropriate answer codes.
A. Assertion and reason both are correct and reason is the correct explanation of Assertion.
B. Assertion and reason both are correct and reason is not the correct explanation of Assertion.
C. Assertion is correct but reason is wrong.
D. Both Assertion and Reason are false.

1. Assertion: Conservation of biodiversity under their natural habitats is called in situ conservation.
   Reason: The Silent Valley of Kerala possesses many rare plans and animals.
2. Assertion: Forest is a vital component of hydrological cycle.
   Reason: Forest also maintain CO2/ O2 cycles.
3. Assertion: Mangroves in India are mainly concentrated in Sundarbans and Andaman- Nicobar Islands.
   Reason: Mangrove vegetation is a source of pollution.
4. Assertion: Botanical gardens and Zoos are man made protection habitats for plants and animals respectively.
   Reason: These two also have a aesthetic value.
5. Assertion: The rate of extinction of organisms has increased in recent years.
   Reason: Human activities like deforestation, industrialization, etc. have destroyed the natural habitat of plants and animals.
6. Assertion: Species diversity decreases as we ascend towards high mountains.
   Reason: Due to drop in temperature, no seasonal variability occurs in high mountains.
7. Assertion: Communities with more species tend to be more stable than those with less species.
   Reason: Communities with more species is not able to resist occasional disturbances.
8. Assertion: Dodo, Passenger pigeon, Steller’s sea cow have become extinct due to over exploitation.
   Reason: Excessive exploitation of a species, whether animal or plant reduces size of it’s population so that it becomes vulnerable to extinction.
9. Assertion: Many endemic species are seen to flourish in sacred forests.
   Reason: Sacred forests are undisturbed forest patches and biodiversity rich areas.
10. Assertion: Buffer zone surrounds the core area and limited human activities like resource use strategies, research and education are allowed here.
    Reason: There is no biotic interference except in buffer zone.
11. Assertion: Alpha diversity refers to species diversity present in a given community or habitat.
    Reason: Alpha diversity is expressed by species richness and species evenness in a community or habitat.
12. Assertion: Eichhornia crassipes drains off oxygen from water and can be seen growing in standing water.
    Reason: Eichhornia crassipes is an indigenous species of India.
13. Assertion: The pyramid of number of a pond ecosystem is upright.
    Reason: Phytoplankton are maximum and secondary consumers are least in number.
14. Assertion: The rate of decomposition of detritus is reduced in the regions of high altitude.
    Reason: It happens due to immobilisation of nutrients.
15. Assertion: The biotic community and non- living environment of an area function together to form an ecosystem.
    Reason: The change in abiotic components causes a change in biotic components also.
16. Assertion: A food chain is a group if organisms in which there is a transfer of food energy through a series of repeated eating and being eaten.
    Reason: Interlocking pattern of several food chain is known as food web.
17. Assertion: Each food level in an ecosystem is called trophic level.
    Reason: When one organism benefits the other in a chain, it is called commensalism.
18. Assertion: Ecological pyramid of biomass is generally inverted in sea/ocean.
    Reason: Biomass of fishes far exceeds that of phytoplankton.
19. Assertion: Ecosystem is assemblage of many populations interacting with each other and also with the environment.
    Reason: Ecosystem is composed of both living and non- living components.
20. Assertion: The pyramid of number in a forest is inverted.
    Reason: There is a constant increase in the number of organisms at each successive trophic level.

Answer Sheet

1. A
2. B
3. C
4. A
5. A
6. A
7. C
8. A
9. A
10. C
11. B
12. C
13. A
14. C
15. A
16. B
17. C
18. A
19. A
20. A

Part 2

The following questions consist of two statements, one labelled as Assertion (A) and the other labelled the Reason ®. Examine these two statements carefully and select the most appropriate answer codes.
A. Assertion and reason both are correct and reason is the correct explanation of Assertion.
B. Assertion and reason both are correct and reason is not the correct explanation of Assertion.
C. Assertion is correct but reason is wrong.
D. Both Assertion and Reason are false.

1. Assertion: Every biological system resists a change to remain in a state of equilibrium.
   Reason: Climax community of a ecosystem is also a stable community produced as a result of many transient changes.
2. Assertion: Fresh water lakes may show Eutrophication.
   Reason: Eutrophic lakes are poor in nutrients.
3. Assertion: An ecosystem can support only a limited number (3-6) of trophic levels in a food chain
   Reason: Only 10% energy is transferred to each successive trophic level.
4. Assertion: The trophic level represents a functional level, not a species.
   Reason: A single species may occupy two or more trophic levels.
5. Assertion: Secondary succession occurs in newly cooled lava sediments.
   Reason: Secondary succession is faster.
6. Assertion: The productivity of oceans are only 55 billion tons.
   Reason: Gross primary productivity is higher than the net primary productivity.
7. Assertion: Pyramid of energy is always upright.
   Reason: There is bidirectional flow of energy.
8. Assertion: The maximum productivity occurs in sugarcane field.
   Reason: Sugarcane is the C4 plant.
9. Assertion: The species that are first to colonize a bare area are called pioneer species.
   Reason: Pioneer species of hydrarch are lichens.
10. Assertion: The amount and seasonal distribution of rainfall play a very important role for type of vegetation.
    Reason: Food chain is unidirectional flow in energy from one trophic level to another.
11. Assertion: The examples of primary consumers are herbivores.
    Reason: Green plants make up primary producer trophic level.
12. Assertion: Animals adopt deferent strategies to survive in hostile environment.
    Reason: Praying mantis is green in colour which merges with plant foliage.
13. Assertion: Cold- blooded animals have no fat layer.
    Reason: Cold-blooded animals use their that fat for metabolic process during hibernation.
14. Assertion: Emigration is outward movement of some individuals from local population.
    Reason: Emigration is caused by occurrence of deficiencies and calamities.
15. Assertion: Many plants growing in oligotrophic soil possess mycorrhizae.
    Reason: Mycorrhizae help in efficient absorption of nutrient.
16. Assertion: Myorrhizal relation exists between Boletus and Pinus.
    Reason: It is a symbiotic interaction.
17. Assertion: Predation and parasitism are considered to be negative interaction.
    Reason: Predators and parasites limit the population of their host species.
18. Assertion: Generally the intraspecific competition is more intense than inter specific competition.
    Reason: Intraspecific competition occurs when the resources are in short supply.
19. Assertion: Amensalism is a negative interaction between two living individuals.
    Reason: In amensalism, allochemicals are secreted by one individual.
20. Assertion: Plant animal interactions involve co-evolution of the mutualist organisms.
    Reason: Evolution of the flower and its pollinator species are tightly linked with one another.

Answer Sheet

1. B
2. C
3. A
4. B
5. D
6. B
7. C
8. B
9. C
10. B
11. A
12. C
13. A
14. B
15. A
16. B
17. A
18. B
19. B
20. A