Q21. Which one of the following is used in preparing a natural mosquito repellent?
(a) Congress grass
(b) Elephant grass
(c) Lemongrass
(d) Nut grass
Solution C
(a) Congress grass – Also known as Parthenium hysterophorus, Congress grass is an invasive weed and is not known to be used as a mosquito repellent.
(b) Elephant grass – Also known as Napier grass or Pennisetum purpureum, Elephant grass is typically used as a fodder crop and doesn’t have properties that make it suitable for mosquito repellent.
(c) Lemongrass – Lemongrass, scientifically known as Cymbopogon, is widely recognized for its insect-repelling properties. It contains citral and geraniol, which are natural compounds known to repel mosquitoes. Many natural mosquito repellents contain lemongrass oil or extracts. Hence Option (c) is correct.
(d) Nut grass – Also known as Cyperus rotundus, nut grass has been used in traditional medicine but isn’t specifically known for its mosquito repellent properties.
Q22. Consider the following kinds of organisms:
1. Copepods
2. Cyanobacteria
3. Diatoms
4. Foraminifera
Which of the above are primary producers in the food chains of oceans?
(a) 1 and 2
(b) 2 and 3
(c) 3 and 4
(d) 1 and 4
Solution B
Primary producers are organisms that synthesize their own food from inorganic substances, usually through the process of photosynthesis. They form the base of the food chain by providing energy and nutrients to other organisms.
1. Copepods: These are small crustaceans and are generally considered consumers rather than primary producers. They feed on phytoplankton and other small organisms.
2. Cyanobacteria: These are photosynthetic bacteria that play a vital role as primary producers in many ecosystems, including oceans. They can produce their own food through photosynthesis.
3. Diatoms: Diatoms are a major group of algae and are among the most common types of phytoplankton. They are primary producers and generate a large portion of the oxygen in the atmosphere. They are also a key source of food in aquatic ecosystems.
4. Foraminifera: These are members of a phylum or class of amoeboid protists. Some foraminifera host photosynthetic algae within their cells and thus can function as primary producers, but they are generally considered consumers in the marine food chain.
Q23. Consider the following animals:
1. Hedgehog
2. Marmot
3. Pangolin
To reduce the chance of being captured by predators, which of the above organisms rolls up and protects its vulnerable parts?
(a) 1 and 2
(b) 2 only
(c) 3 only
(d) 1 and 3
Solution D
1. Hedgehog: Hedgehogs are known to roll up into a ball to protect their vulnerable underparts. Their spines provide a shield against predators, making it difficult for them to be eaten. Hence, this option is correct.
2. Marmot: Marmots are large squirrels found in mountainous areas, and they do not roll up to protect themselves from predators. Instead, they rely on burrowing and hiding in rocky environments. Hence, this option is not correct.
3. Pangolin: Pangolins are known to curl up into a ball when threatened, using their tough, overlapping scales to protect their soft and vulnerable underside. This makes it hard for predators to penetrate their defense. Hence, this option is correct.
Q24. With reference to the ‘New York Declaration on Forests’, which of the following statements are correct?
1. It was first endorsed at the United Nations Climate Summit in 2014.
2. It endorses a global timeline to end the loss of forests.
3. It is a legally binding international declaration.
4. It is endorsed by governments, big companies, and indigenous communities.
5. India was one of the signatories at its inception.
Select the correct answer using the code given below.
(a) 1, 2 and 4
(b) 1, 3 and 5
(c) 3 and 4
(d) 2 and 5
Solution A
The New York Declaration on Forests (NYDF) is a political declaration calling for global action to protect and restore forests. It offers a common, multi-stakeholder framework for forest action, consolidating various initiatives and objectives that drive forest protection, restoration, and sustainable use.
The New York Declaration on Forests was indeed first endorsed at the United Nations Climate Summit in September 2014. Hence Option 1 is correct.
The Declaration includes a goal to end natural forest loss globally by 2030. So, it does endorse a global timeline to end the loss of forests. Hence Option 2 is correct.
The New York Declaration on Forests is not a legally binding agreement, rather it’s a voluntary commitment. Hence Option 3 is incorrect.
The Declaration has been endorsed by more than 150 governments, companies, indigenous communities, and NGOs. Hence Option 4 is correct.
India did not sign the New York Declaration on Forests at its inception. Hence Option 5 is incorrect.
Q25. Magnetite particles, suspected to cause neurodegenerative problems, are generated as environmental pollutants from which of the following?
1. Brakes of motor vehicles
2. Engines of motor vehicles
3. Microwave stoves within homes
4. Power plants
5. Telephone lines
Select the correct answer using the code given below.
(a) 1, 2, 3 and 5 only
(b) 1, 2 and 4 only
(c) 3, 4 and 5 only
(d) 1, 2, 3, 4 and 5
Solution B
Magnetite is a type of iron oxide that has magnetic properties, and studies have shown that airborne magnetite particles are associated with certain environmental sources.
1. Brakes of motor vehicles: Friction from brake wear can generate magnetite particles. This statement is correct.
2. Engines of motor vehicles: Combustion engines can emit magnetite particles due to the wear of components and the combustion process. This statement is correct.
3. Microwave stoves within homes: There’s no strong evidence to suggest that microwave stoves generate magnetite particles. This statement is likely incorrect.
4. Power plants: Depending on the type of fuel burned and the technology used, power plants may emit magnetite particles. This statement is correct.
5. Telephone lines: There’s no direct link between telephone lines and magnetite particles. This statement is likely incorrect.
Q26. Which one of the following is a filter feeder?
(a) Catfish
(b) Octopus
(c) Oyster
(d) Pelican
Solution C
A filter feeder is an animal that feeds by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure.
Catfish: Some catfish species are bottom feeders, and although they might sift through mud to find food, they are not typically classified as filter feeders.
Octopus: Octopuses are predators that catch prey with their arms and suckers, not filter feeders.
Oyster: Oysters are well-known filter feeders. They feed by filtering plankton and other small particles from the water.
Pelican: Pelicans are primarily fish-eating birds that scoop up fish in their large bills. They are not classified as filter feeders.
Q27. In case of which one of the following biogeochemical cycles, the weathering of rocks is the main source of release of nutrient to enter the cycle?
(a) Carbon cycle
(b) Nitrogen cycle
(c) Phosphorus cycle
(d) Sulphur cycle
Solution C
(a) Carbon Cycle: The carbon cycle involves the exchange of carbon among the atmosphere, oceans, and terrestrial biosphere. While weathering of rocks can release carbon into the soil, it’s not the main source of carbon for this cycle. There is no single “main” source, as carbon is cycled through various processes and reservoirs.
(b) Nitrogen Cycle: The nitrogen cycle is primarily driven by microbial processes that convert nitrogen between various forms, including nitrogen gas, ammonium, nitrate, and organic nitrogen. Atmosphere is the main source of nitrogen for this cycle.
(c) Phosphorus Cycle: Unlike other major biogeochemical cycles, the phosphorus cycle does not include a major gaseous phase. Phosphorus mainly cycles through the land, water, and sediments. The weathering of rocks containing phosphate minerals is a key source of phosphorus for this cycle, releasing it into the soil and water.
(d) Sulphur Cycle: The sulphur cycle involves the transformation of sulphur between various forms, including sulphate, sulphide, and organic and inorganic compounds. While weathering can release sulphur, it’s not the main source for this cycle.
Q28. Which of the following are detritivores?
1. Earthworms
2. Jellyfish
3.Millipedes
4. Seahorses
5. Woodlice
Select the correct answer using the code given below.
(a) 1, 2 and 4 only
(b) 2, 3, 4 and 5 only
(c) 1, 3 and 5 only
(d) 1, 2, 3, 4 and 5
Solution C
Detritivores are organisms that feed on detritus or decaying organic material, breaking it down into smaller parts. They play an essential role in nutrient cycling by helping to decompose organic matter.
1. Earthworms: Earthworms are well-known detritivores, feeding on decaying plant material and other organic matter. They are correct.
2. Jellyfish: Jellyfish are mainly carnivorous, feeding on small fish, zooplankton, and other jellyfish, not on detritus. They are not detritivores.
3. Millipedes: Millipedes feed on decaying organic matter, including dead leaves and wood, making them detritivores. They are correct.
4. Seahorses: Seahorses are carnivorous and feed mainly on small crustaceans and other small animals, not on decaying organic matter. They are not detritivores.
5. Woodlice: Woodlice are detritivores that feed on decaying plant material, and sometimes even dead animals. They are correct.
Q29. The ‘Common Carbon Metric’, supported by UNEP, has been developed for:
(a) assessing the carbon footprint of building operations around the world
(b) enabling commercial farming entities around the world to enter carbon emission trading
(c) enabling governments to assess the overall carbon footprint caused by their countries
(d) assessing the overall carbon foot-print caused by the use of fossil fuels by the world in a unit time
Solution A
The Common Carbon Metric (UNEP) is the calculation used to define measurement, reporting, and verification for GHG emissions associated with the operation of buildings types of particular climate regions. It does not include value-based interpretation of the measurements such as weightings or benchmarking.
While it is not a building rating tool, it is consistent with methods for assessing the environmental performance of buildings used globally.
The Common Carbon Metric is applied to the specific inventory of the buildings under study. Such an inventory can be developed from a top-down or bottom-up approach, depending on the scope and goal of the investigation
Q30. Which of the following have species that can establish symbiotic relationship with other organisms?
1. Cnidarians
2. Fungi
3. Protozoa
Select the correct answer using the code given below.
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Solution D
1. Cnidarians: Cnidarians, such as corals, can establish symbiotic relationships with other organisms. For example, coral reefs have a well-known symbiotic relationship with algae called zooxanthellae. The algae produce oxygen and help the coral remove wastes, while the coral provides a protective environment for the algae and compounds they need for photosynthesis.
2. Fungi: Many fungi form symbiotic relationships with plants, known as mycorrhizae. In this relationship, the fungi help the plants absorb water and nutrients, while the plants provide sugars and other organic substances to the fungi.
3. Protozoa: Some protozoa can also engage in symbiotic relationships. For example, termites have symbiotic protozoa in their guts that help them digest cellulose.