Environment and Biodiversity Mock Test

Correct Answer - (d) Reptiles

• Indicator species reflect the quality and changes in environmental conditions.
• Following are the few examples of the indicator species:
  • Stoneflies → Indicate high oxygen water
  • Mosses → Some moss species indicate acidic soil.
  • Lichens → Very sensitive to air pollution
  • Mollusca → Indicate water pollution status
• Reptiles are not indicator species.

Correct Answer - (a) 1 only

• Eutrophication is the process by which a body of water acquires a high concentration of nutrients, especially phosphates and nitrates.
• These typically promote excessive growth of algae that deplete the water of available oxygen, causing the death of other organisms, such as fish.

Correct Answer - (a) Upright

• Pyramid of energy is a graphic representation of the amount of energy trapped in different trophic levels of a food chain with producers forming the base and the top carnivores at the tip.
• Pyramid of energy is always upright as almost 80% of the energy is used at lower trophic level and only about 10% of the energy is available to the next trophic level.

Correct Answer - (c) Both 1 and 2

• Ecotone is a junction between two or more diverse ecosystems.
• It is the zone in which two communities integrate to live together.
• Ecotone contains not only species common to the communities on both sides but also a number of highly adaptable species that colonize such transitional zones.
• Hence biodiversity is higher at ecotones.

Correct Answer - (a) 1 only

• A keystone species is a species that has a disproportionately large effect on its ecosystem.
• Any organism, including animals, plants, bacteria, and fungi can be a keystone species.
• Some examples of keystone species are Starfish, Wolves, Sea otters etc.

Correct Answer - (d) Deserts

• An ecotone is a transitional area between diverse ecosystems. 
• some examples of ecotones:
• Mangrove forests → The transition zone between marine and terrestrial ecosystems.
• Estuaries →  The transition zone between freshwater and marine ecosystems.

Grasslands →  The transition zone between desert and forest ecosystems.

Correct Answer - (d) Tropical rainforest >  Tropical seasonal forest >  Temperate Grasslands.

• Tropical rainforest has higher productivity than Tropical seasonal forest
• Tropical seasonal forest has higher productivity than Temperate Grasslands.

Correct Answer - (c) Glass objects

• The waste materials which cannot be broken down into non-poisonous or harmless substances in nature are called non-biodegradable waste. 
• Plastics, polythene bags, ball-point pen refills, synthetic fibers, and glass objects etc. are examples of non-biodegradable material.
• Cotton cloth, paper, Wooden furniture etc. are biodegradable.

Correct Answer - (d) Biosphere

• Biosphere is the largest entity among the above which includes all the biomes and ecosystems hence it has the largest population of species.

Correct Answer - (c) Both 1 and 2

• Invasive alien species  are species whose introduction or spread outside their natural ecosystem threatens biological diversity.
• Common features of Invasive alien species:
  • Rapid reproduction and growth
  • High dispersal
  • Ability to survive on various food types
  • Ability to survive in a wide range of environmental conditions.
• Examples of Invasive alien species:
  • Lantana (Lantana Camara):
  • Water Hyacinth

Correct Answer - (a) Laterite soils

• A thick brown/black substance that remains after most of the organic litter has decomposed is called humus. Earthworms help in mixing humus with minerals in the soil. 
• This process is called humification.
• Laterite soil is found in warm and wet tropical areas.
• It has low humus content because the high temperatures destroy microorganisms which are needed for decomposition of organic matter.

Correct Answer -  (a) Tropical deciduous forests

• Sandalwood is a small tropical tree which is famous for its distinctive fragrance.
• They are found in Tropical deciduous forests where the rainfall is between 100 cm to 200 cm.
• Tropical deciduous forests are characterized by trees that shed their leaves during a particular time of the year, usually in response to a dry season.

Correct Answer - (b) 2 only

• Sacred groves are forest areas that are protected by local communities as they have cultural or religious significance. 
• Such forests are preserved in their virgin form by the local tribal communities.
• Some examples in India:
  • Law Lyngdoh in Meghalaya
  • Devbani in Chhattisgarh
  • Sarnas in Jharkhand

Correct Answer - (a) 1 only

• Corals are invertebrate animals belonging to a large group of colorful marine organisms called Cnidaria.
• Each individual coral animal is called a polyp.
• They live in the colony of hundreds to thousands.
• Over the years, coral polyps can create massive reef structures which are made polyps secrete calcium carbonate (CaCO3).
• They are confined to tropical and semitropical waters of the world.
• They have the highest primary productivity within the sea.

Correct Answer - (a) Pacific Ocean

• The Pacific Ocean has the most coral reefs in the world.
• The Indo-West Pacific region has over 90% of the world's coral reefs.
• The Pacific Ocean has about twice as many coral species as the Atlantic Ocean.

Correct Answer - (c) Both 1 and 2

• Phytoplankton, also known as microalgae, are similar to terrestrial plants as they contain chlorophyll and require sunlight to perform photosynthesis.
• Some phytoplankton are bacteria and most are single-celled plants.
• Cyanobacteria, Silica-encased diatoms, Dinoflagellates and Green algae are some examples of phytoplanktons.
• Most phytoplanktons thrive in the upper part of the ocean, where sunlight penetrates the water.

Correct Answer - (a) Wetlands 

• The Ramsar Convention on wetlands of international importance, also known as Ramsar convention, is an international treaty for conservation as well as sustainable use of wetlands.
• It was signed at Ramsar, Iran, in 1971.

Correct Answer - (c) Loktak Lake

• The Montreux Record is a register of Ramsar sites where changes in ecological character have occurred or are currently occurring due to technological developments, pollution or other human interference.
• Indian sites included in the Montreux Record are Keoladeo National Park(Rajasthan), Loktak Lake(Manipur).

Correct Answer - (c) Both 1 and 2

• Higher concentrations of NO2 can damage the leaves of plants and harm the rate of photosynthesis.
• Nitrogen dioxide is also a lung irritant that can lead to an acute respiratory disease especially in children.

Correct Answer - (c) Both 1 and 2

• • Smog is caused by the burning of large amounts of coal and other hydrocarbons, vehicular emission and industrial emissions.
  • smog are recognized into two types:

• Photochemical smog:

• • •  Also known as ‘Los Angeles smog’.
    • Contains high concentration of Nitrogen Oxides.
    • Particularly caused by automobile emissions.
    • It leads to formation of ground level ozone which is a secondary pollutant.

• Sulfurous Smog:

• • Also called ‘London smog’.
  • Contains high concentration of Sulfur Oxides.
  • Particularly caused by burning of Coal.
• In cold temperatures, Pollutants remain in the atmosphere for a longer period of time which aggravates smog.

Correct Answer - (c) Both 1 and 2

• After deforestation, soil becomes exposed and rainwater can easily leach away nutrients in run-off water. 
• This causes  the fertility of soil to decline.
• Removal of the top layer of the soil during deforestation exposes the lower, hard layer which is less fertile.
• Gradually the fertile land gets converted into deserts which is called desertification.

Correct Answer - (a) 1 and 2 only

• Hot water released from plants and industries raises the average temperature of the waterbody, adversely affecting the animals and plants living in it.
• High concentration of nutrients in a waterbody causes eutrophication (algal bloom) in water bodies resulting in higher consumption of oxygen and loss to aquatic life.
• Phytoplankton are not harmful for aquatic life.

Correct Answer - (a) 1 only

• Fly ash is a fine, powdery material that's a byproduct of burning coal in power plants.
• It contains toxic pollutants like lead, zinc, arsenic, cadmium, sulfur, mercury and radioactive substances like uranium isotopes, which adversely impacts the health of the people near the power stations.

Correct Answer - (c) Both 1 and 2

• Electronic waste (e-waste), is a generic term used to describe all types of old and discarded electrical and electronic equipment such as household appliances, computer and laptops, communications equipment etc.
• They contain high amounts of toxic chemicals including metals such as lead, cadmium, mercury, and nickel.
• Unsafe disposal of e-waste involves significant risk to health as harmful gasses are emitted during the process.
• Leaking of materials such as heavy metals can cause groundwater pollution which affects a large population.

Correct Answer - (c) Both 1 and 2

• Black carbon is formed due to incomplete combustion of fossil fuels, biofuel, and biomass.
•  It is a type of aerosol.
• When it falls to earth with precipitation, it darkens the surface of snow and reduces its albedo which leads to warming and melting of the snow.