Static Quiz 23 May 2024 (Environment)

Both the statements are correct.

An indicator species is a species whose presence, absence or abundance, and changes therein, can indicate certain environmental conditions. Changes in indicator species’s populations are used to monitor changes in particular ecosystems and sometimes trends affecting the environment as a whole.
• Tubifex tubifex, also called the sludge worm, or sewage worm, is a species of tubificid segmented worm that inhabits the sediments of lakes and rivers on several continents.
• Tubifex tubifex is used as a water quality indicator because of its ability to tolerate low oxygen conditions, the presence of heavy metals, and other environmental conditions.
• Mosses are reliable indicators of air pollution risks to ecosystems, because they get most of their nutrients direct from the air and rain, rather than the soil. Ecosystems dominated by mosses and lichens are amongst the most sensitive to nitrogen pollution. Because mosses are so good at absorbing nitrogen they prevent it from leaching into ground water, but if they get overloaded they quickly deteriorate. Some moss species are especially sensitive to increased levels of nitrogen.

Acid rain is a mixture of deposited material, both wet and dry, contributed by more than normal amounts of nitric and sulphuric acids. Hence statement 1 is correct.

Acidity is determined on the basis of the pH level of the water droplets. Normal rain water is slightly acidic with a pH range of 5.3-6.0, because carbon dioxide and water present in the air react together to form carbonic acid, which is a weak acid. When the pH level of rainwater falls below this range, it becomes acid rain. Hence statement 2 is incorrect.

In-situ Conservation:
• It is the methods of conserving all the living species, especially the wild and endangered species in their natural habitats and environment. In-situ conservation of Biodiversity includes biosphere reserves, national parks, wildlife sanctuaries, etc

Ex-situ Conservation:
• It is the methods of conserving all the living species in the artful habitats that reflect their natural living habitats. Examples of ex-situ conservation of biodiversity include aquariums, botanical gardens, cryopreservation, DNA banks, zoos, etc.

Primary air pollutants: Pollutants that are formed and emitted directly from particular sources. Examples are particulates, carbon monoxide, nitrogen oxide, Volatile Organic Compounds and sulfur oxide

Secondary air pollutants are also harmful chemicals but they are produced from chemical reactions involving the primary pollutants. E.g. Ozone and Sulphur Trioxide.

Based on the their life form or location, aquatic organisms (both flora and fauna) are classified into five groups:
Neustons: Unattached organisms which live at air-water interface such as floating plants etc.
Periphytons: There are organisms which remain attached to stems and leaves of rooted plants or substances emerging above the bottom mud such as sessile algae.
Planktons: These are free floating species with limited powers of locomotion. This group includes microscopic plants like algae(phytoplankton) and animals like crustaceans and protozoans (zooplankton).
Nektons: This group includes animals which are swimmers. The animals range in size from the swimming insects to the largest animals, blue whale.
Benthos: These are found living in the bottom of the water mass.