01 July 2024

Q1. What does the term “benthic” refer to in marine ecology?

(a) Fish that swim near the ocean’s surface.

(b) Organisms that live on or in the ocean floor.

(c) Coral reefs found in shallow waters.

(d) The movement of ocean currents.

Ans: (b)

Explanation:

• Benthic refers to the ecological region at the bottom of a body of water, such as the ocean or a lake. This region includes the sediment surface as well as the organisms that live on or in it. Benthic organisms can range from small bacteria and microorganisms to larger organisms like crabs, sea stars, and various species of fish. They play a crucial role in marine ecosystems by decomposing organic matter, recycling nutrients, and providing a food source for other organisms. Therefore, option B is the correct answer as it accurately defines the term “benthic” in marine ecology.

Q2. Which of the following is/are the possible consequence/s of heavy sand mining in riverbeds?

1. Decreased salinity in the river
2. Pollution of groundwater
3. Lowering of the water-table

Select the correct answer using the code given below:

(a) 1 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Ans: (b)

Explanation:

• The removal of sand from the river bed increases the velocity of the flowing water, with the distorted flow-regime eventually eroding the river banks.
• Sand acts like a sponge, which helps in recharging the water table; its progressive depletion in the river is accompanied by declining water tables in the nearby areas.
• Depletion of sand in the stream bed causes the deepening of rivers and estuaries, and the enlargement of river mouths and coastal inlets. It leads to saline-water intrusion.
• Sand acts as an efficient filter for various pollutants and thus maintains the quality of water in rivers and other aquatic ecosystems.

Q3. Consider the following statements:

1. Invasive alien species (IAS) are native to the ecosystem they invade.
2. IAS can outcompete native species for resources.
3. IAS are always intentionally introduced by humans.
4. The impact of IAS on ecosystems is always positive.

How many of the above statements given is/are correct?

(a) Only one

(b) Only two

(c) Only three

(d) All four

Ans: (a)

Explanation:

• S1: This statement is incorrect. Invasive alien species are not native to the ecosystem they invade. They are species that have been introduced to a new ecosystem, often by human activities, and they can cause harm to the native species and the ecosystem.
• S2: This statement is correct. One of the defining characteristics of invasive alien species is their ability to outcompete native species for resources such as food, water, and habitat. This competitive advantage can lead to a decline in native species populations.
• S3:This statement is incorrect. While many invasive species are introduced to new ecosystems unintentionally, such as through shipping or trade, some are intentionally introduced for various purposes like agriculture or ornamental gardening.
• S4: This statement is incorrect. The impact of invasive alien species on ecosystems is almost always negative. They can disrupt ecological balances, displace native species, and reduce biodiversity. Their introduction is often associated with ecological and economic harm.

Q4. Which of the following statements is/are correct regarding the Biological Diversity Act, 2002?

1. The main intent of this legislation is to protect India’s rich biodiversity and associated knowledge against their use by foreign individuals.
2. It seeks to check biopiracy, protect biological diversity and local growers through a three-tier structure of central and state boards and local committees.
3. It provides for setting up of a National Biodiversity Authority (NBA) and State Biodiversity Boards (SBBs).

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 and 3 only

(c) 1 and 2 only

(d) 1, 2 and 3

Ans: (d)

Explanation:

• Enacted for the conservation of biological diversity and fair, equitable sharing of the monetary benefits from the commercial use of biological resources and traditional knowledge.
• The main intent of this legislation is to protect India’s rich biodiversity and associated knowledge against their use by foreign individuals.
• It seeks to check biopiracy, protect biological diversity and local growers through a three-tier structure of central and state boards and local committees.
• The Act provides for setting up of a National Biodiversity Authority (NBA), State Biodiversity Boards (SBBs) and Biodiversity Management Committees (BMCs) in local bodies.
• The NBA will enjoy the power of a civil court.

Q5. Consider the following statements about  United Nations Convention on Biological Diversity (UNCBD):

1. It is a legally binding treaty.
2. It comes under the United Nations Environment Programme (UNEP).
3. The CBD Secretariat is based in Montreal, Canada.

How many of the statements given above is/are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

Ans: (c)

Explanation:

• Convention on Biological Diversity is a legally binding treaty , which came as an outcome of the Earth Summit in Rio de Janeiro on 5 June 1992.
• The CBD Secretariat is based in Montreal, Canada and it operates under the United Nations Environment Programme.