Daily Static MCQs Quiz for UPSC, IAS, UPPSC/UPPCS, MPPSC. BPSC, RPSC & All State PSC Exams
Subject : Environment & Ecology
1. Consider the following statements regarding Parasitism:
1. Parasitism occurs when two organisms interact, but while
one benefits, the other experiences harm.
2. Tapeworm attaching itself to the intestine of a cow is an example of
Parasitism.
3. The parasite always kills the host.
How many of the above statements are correct?
(a) Only one
(b) Only two
(c) All three
(d) None
Answer: (B)
Explanation: A parasite is an organism that lives in or on another living organism, deriving nutrients from it. In this relationship the parasite benefits, but the organism being fed upon, the host, is harmed. The host is usually weakened by the parasite as it siphons resources the host would normally use to maintain itself. The parasite, however, is unlikely to kill the host. This is because the parasite needs the host to complete its reproductive cycle by spreading to another host.
The reproductive cycles of parasites are often very complex, sometimes requiring more than one host species. A tapeworm is a parasite that causes disease in humans when contaminated, undercooked meat such as pork, fish, or beef is consumed. The tapeworm can live inside the intestine of the host for several years, benefiting from the food the host is bringing into its gut by eating. The parasite moves from species to species as it requires two hosts to complete its life cycle. Hence, only statement 3 is incorrect.
2. To avoid unfavourable conditions, which of the following enter into diapause, a stage of suspended development?
(a) Zooplankton
(b) Bears
(c) Snails
(d) Fish
Answer: (A)
Explanation: In animals, the organism, if unable to migrate, might avoid the stress by escaping in time. The familiar case of bears going into hibernation during winter is an example of escape in time. Some snails and fish go into aestivation to avoid summer–related problems-heat and dessication. Under unfavourable conditions many zooplankton species in lakes and ponds are known to enter diapause, a stage of suspended development. Hence, option (a) is correct.
3. Consider the following statements:
1. When the soil becomes dry, the capability of the plants to
act as carbon sink reduces.
2. With increase in soil temperature, the microorganisms in dry soil become more
productive.
Which of the above statements is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (C)
Explanation: When the soil is dry, plants become stressed and cannot absorb as much carbon dioxide as in the normal conditions. The capability of plants to act as carbon sink reduces. Microorganisms in the dry soil become more productive, when the climate is hot and release more carbon dioxide. Hence, both statements are correct.
4. Acid rain is mainly a by-product of a variety of human activities that emit the oxides of:
(a) Sulphur and nitrogen in the atmosphere
(b) Mercury and lead compounds in water bodies
(c) Radioactive compounds in effluent discharge
(d) Carbon emitted by peat lands
Answer: (A)
Explanation: Burning of fossil fuels (which contain sulphur and nitrogenous matter) such as coal and oil in power stations and furnaces or petrol and diesel in motor engines produce sulphur dioxide and nitrogen oxides. SO2 and NO2 after oxidation and reaction with water are major contributors to acid rain, because polluted air usually contains particulate matter that catalyzes the oxidation. These lead to formation of acid rain that has deleterious effect on the overall ecology of the region. Hence, option (a) is correct.
5. Consider the following statements regarding Wetlands:
1. In India, Wetlands are regulated under the Environment
(Protection) Rules, 1986.
2. Wetlands International is sub-branch of UN Environment that works to sustain
and restore wetlands and their resources for people and biodiversity.
Which of the above statements is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (D)
Explanation: Wetlands are regulated under the Wetlands (Conservation and Management) Rules. Wetlands International is a global organisation that works to sustain and restore wetlands and their resources for people and biodiversity. It is an independent, not-for-profit, global organisation, supported by government and NGO membership from around the world. Hence, both statements are incorrect.
