Important facts for the Exam MCQs with Explanations
This section contains the most important facts, key concepts, one-liners and quick revision points from Environment and Ecology. It is designed to help aspirants revise important topics efficiently before examinations.
Which of the following is correct sequence of ecosystem in order of decreasing productivity?
Correct Answer:
(C) Mangroves, Grasslands, Lakes and Oceans
The correct sequence of ecosystem in order of decreasing productivity is- Mangroves, Grasslands, Lakes and Oceans. Despite occupying about 70 percent of the surface, the productivity of the oceans are only 55 billion tons. Hence option (c) is correct.
Ques: 2
Concerning ‘Eco-Sensitive Zones’, which of the following statements is/are correct?
Eco-Sensitive Zones are the areas that are declared under the Wildlife (Protection) Act, 1972.
The purpose of the declaration of Eco-Sensitive Zones is to prohibit all kinds of human activities in those zones except agriculture.
Select the correct answer using the code given below:
Correct Answer:
(D)
Neither 1 nor 2
Eco - sensitive zones are mentioned under the Environment (Protection) Act, 1986. Hence statement 1 is incorrect.
Prohibited activities: Tourism activities like flying over protected areas in an aircraft or hot air balloon, and discharge of effluents and solid waste in natural water bodies or terrestrial areas.
Regulated activities: Felling of trees, establishment of hotels and resorts, commercial use of natural water, erection of electrical cables, drastic change of agriculture system, e.g. adoption of heavy technology, pesticides etc. widening of roads.
Permitted activities: Ongoing agriculture and horticulture practices by local communities, rainwater harvesting, organic farming, adoption of green technology and use of renewable energy sources.
Hence, statement 2 is also incorrect. Hence, option (d) is the correct answer.
Ques: 3
Which one of the following statements best describes the term ‘Social Cost of Carbon’? It is a measure, in monetary value, of the:
Correct Answer:
(A) long-term damage done by a tonne of CO2 emissions in a given year.
Social Cost of Carbon or SC-CO2 is a measure, in monetary value, of the long-term damage done by a tonne of carbon dioxide (CO2) emission in a given year. EPA (Environmental Protection Agency) and other federal agencies use estimates of the social cost of carbon to evaluate the climate impacts of rulemaking.
Ques: 4
The pyramid of energy in any ecosystem is
Correct Answer:
(A) Always upright
Pyramid of energy is always upright, can never be inverted, because when energy flows from a particular trophic level to the next trophic level, some energy is always lost as heat at each step. Each bar in the energy pyramid indicates the amount of energy present at each trophic level in a given time or annually per unit area. Hence option (a) is correct.
Ques: 5
Biomass Pyramid is reversed in which type of ecosystem?
Correct Answer:
(B) Pond
The Pyramid of Biomass is a graphical representation that depicts the extent of biomass per unit area within different trophic levels in an ecological system. In grasslands and forests, there is a gradual decrease in the biomass of organisms at successive levels from the producers to the top carnivores. Thus, pyramids are upright. However, in a pond, as the producers are small organisms, their biomass is least and this value gradually shows an increase towards the apex of the pyramid, thus making the pyramid inverted in shape.
Note: An inverted pyramid of biomass can be found in marine ecosystem. The pyramid of biomass in sea is generally inverted because the biomass of fishes far exceeds that of phytoplankton.
Ques: 6
Which of the following statements is true about Bionomics?
It means “management of life’.
It is synonymous with ecology.
It stresses the value of natural systems which influence human systems.
Code :
Correct Answer:
(C) 2 and 3
In ecology, bionomics (Greek: bio = life; nomos = law) is the comprehensive study of an organism and its relation to its environment. Another way of expressing this word is the term currently referred to as “ecology”. It stresses the value of natural systems which influence human systems and is not related to the management of life.