Environment and Ecology: UPSC Previous Year Questions (Prelims)

Explanation

Many animals are predators, parasites or parasitoids, using other animals as food. They use a great diversity of hunting strategies and behaviours to capture or feed on their prey. Invertebrate predators, parasites and parasitoids play an important role in keeping many animal populations under control. Parasitoid is an insect whose larvae feed and develop within or on the bodies of other arthropods. Each parasitoid larva develops on a single individual and eventually kills that host. Most parasitoids are wasps, but some flies and a small number of beetles (carabid beetles), moths, lacewings, and even one caddisfly species have evolved to be parasitoids. Parasitoids alone number about 68,000 named species, and most have yet to be named and described. Predator: They are organisms that capture and eat another (the prey). This act is called predation. The predatory invertebrates include scorpions, centipedes, predatory mites, predatory snails and slugs, nematodes and planarian worms. Detritivores: Termites are detritivores that eat dead and decaying organic matter like logs of wood in a forest. They form an important link in the cycling of nutrients in the forests by breaking down wood and organic residues on the ground

Explanation

The banyan fig tree Ficus microcarpa is famous for its aerial roots, which sprout from branches and eventually reach the soil. Aerial roots are roots above the ground that are found in diverse plant species like mangroves, banyan figs and orchids. The tree also has a unique relationship with a wasp that has co-evolved with it and is the only insect that can pollinate it. Figs are known to sustain at least 1,200 bird and mammal species. Fig trees were among the earliest domesticated crops and appear as sacred symbols in Hinduism, Buddhism and other spiritual traditions.

Explanation

Butterflies: Hybrid Heliconius butterflies are poisonous in nature. In nature, these butterflies are rare. Heliconius melpomene and Heliconius cydno are both highly poisonous, having evolved to produce their own cyanide, and predators have learned exactly what both of these toxic insects look like. Fish: "Venomous" fish are those that can inject their toxic venom into victims, whereas "poisonous" fish are those that cause toxic symptoms only if they are eaten. For example: Lionfish, red-bel-lied piranha etc. Frogs: Frogs are amphibians which can survive both on land and water. Some of them can be poisonous also. Poison dart frogs are small, brightly colored amphibians that live on tropical rainforest floors across Central and South America. Poison dart frogs are named for the toxins they secrete from their skin, which have traditionally been used to tips of hunters’ weapons. For example, the Embera and Noanama Indigenous people in western Colombia have used the skin of golden poison frogs (Phyllobates terribilis) to tip blowgun darts for hundreds of years.

Explanation

Pair 1 is incorrectly matched: The Indri is endemic to the island country of Madagascar, specifically inhabiting the eastern rainforests. The unique geographical features and climate of Madagascar have facilitated the evolution of numerous species found nowhere else on Earth, including the Indri.

Pair 2 is incorrectly matched: Elk is the largest and most advanced subspecies of red deer, found in North America and in the high mountains of Central Asia. It is a member of the deer family. Recent genetic studies suggest that the "red deer" may have three species:

European red deer.

Tibetan-West Chinese red deer.

Elk.

Pair 3 is incorrectly matched: Bonobos and chimpanzees look very similar and both share 98.7% of their DNA with humans--making the two species our closest living relatives. Bonobos are usually a bit smaller, leaner, and darker than chimpanzees. They are found only in the Democratic Republic of Congo. Their discontinuous range extends from the Lualaba River in the east to the Kasai/Sankuru Rivers in the south and as far as the Congo River in the west and around Lake Tumba/Lake Mai-Ndombe.

Explanation

Statement 1 is correct: Both males and females of the lions are polygamous and breed throughout the year, but females are usually restricted to one or two adult males of their pride. In captivity, lions often breed every year, but in the wild, they usually breed no more than once in two years. Females are receptive to mating for three or four days within a widely variable reproductive cycle.

Statement 2 is correct: There are four big cats that can roar: lion, tiger, leopard and jaguar - all of which belong to the genus Panthera. In these species, the epihyal bone, part of the voice box, is replaced by a ligament. This can be stretched, creating a larger sound-producing passage and thus a wider range of pitch. The bones of the cheetah’s voice box form a fixed structure, with divided vocal cords that vibrate with both in and out breaths. This structure is the same for all the ’small’ cats. While this design enables these cats to purr continuously, it limits the range of other sounds and prevents them from being able to roar.

Statement 3 is incorrect: Leopards are known for their solitary nature and impressive hunting abilities. They are skilled predators that primarily hunt at night, using their incredible agility and stealth to catch a variety of prey. Leopards are considered opportunistic hunters, adapting and targeting different species based on availability and their specific habitat. To avoid competition and conflicts, leopards establish their own territories, marking them with scent and claw marks on trees. Male leopards will fiercely defend their territories if they overlap with other males.

Explanation

Sustainable aviation fuel (SAF), hydrogen and electric all have a role to play in the decarbonization of aviation. SAF is vitally important as it can address decarbonization of fuel over its lifecycle, and this is now available to be used in all turbine engines including in mid and long-range aircraft. Therefore, understanding the feedstock landscape as well as the technology pathways is integral to maximising the production and supply of SAF. The production of SAF starts with one of five main families of raw materials:

Corn grain Oil seeds Algae Other fats, oils, and greases Agricultural residues Forestry residues Wood mill waste Municipal solid waste streams Wet wastes (manures, wastewater treatment sludge) Dedicated energy crops.

Explanation

Distributed energy resources, or DERs, are small-scale energy systems that power a nearby location. DERs can be connected to electric grids or isolated, with energy flowing only to specific sites or functions. DERs include both energy generation technologies and energy storage systems. When energy generation occurs through distributed energy re-sources, it is referred to as distributed generation. Examples of distributed energy resources that can be installed include:

Roof top solar photovoltaic units Wind generating units Battery storage Batteries in electric vehicles used to export power back to the grid Combined heat and power units, or tri-generation units that also utilise waste heat to provide cooling Biomass generators, which are fuelled with waste gas or industrial and agricultural by-products. Open and closed cycle gas turbines Reciprocating engines (diesel, oil) Hydro and mini-hydro schemes Fuel cells.

Explanation

Marsupials are a group of mammals commonly referred to as pouched mammals, such as kangaroos and wallabies. These animals are characterized by giving birth to underdeveloped young, which then continue their development in the mother’s pouch (marsupium). They give live birth, but they do not have long gestation times like placental mammals. The pouch provides protection and access to nourishment during this critical growth stage. Statement-I is correct: Marsupials can be observed in regions spanning Australia, Papua New Guinea, and South America. They are not naturally found in India. Examples of marsupials include kangaroos, wallabies, wombats, opossums, bandicoots, and koalas. Statement-II is incorrect: These creatures predominantly inhabit arid and semi-arid areas, and they are not restricted solely to montane grasslands. Marsupials are highly adaptable and thrive in a variety of habitats, including forests, deserts, grasslands. Additionally, they coexist with predators like dingoes, eagles, and foxes in their natural environments.

Explanation

Option 1 is incorrect: Lion-tailed Macaque, also referred to as the wanderoo, inhabits the upper canopy of tropical evergreen rainforests and monsoon forests across various elevations. This species is endemic to the Western Ghats. They are diurnal which means it is active during the day and not nocturnal. IUCN Red List: Endangered Option 2 is correct: Malabar Civet is endemic to the Western Ghats of India. It is listed as Critically Endangered on the IUCN Red List. The Malabar civet is considered nocturnal and so elusive that little is known about its biology and ecology apart from habitat use. IUCN Red List: Critically Endangered Option 3 is incorrect: The Sambar, a large deer native to the Indian subcontinent and Southeast Asia, is crepuscular, active during twilight (morning and evening), and occasionally after sunset. Males are mostly solitary while females form small herds of up to 16 individuals. IUCN Red List: Vulnerable

Explanation

The waggle dance is a unique form of communication performed by honey bees (Apis mellifera) to convey information about the direction and distance of food sources, water, or potential nesting sites to other members of their hive. Worker honeybees, all of which are females, constitute the only bees typically observed flying outside the hive by the general populace. Bees perform two distinct types of dances: The Round Dance and the Tail-wagging or Waggle Dance. The waggle dance of honeybees has long been recognized as a behaviour that communicates in-formation about resource location from a foraging worker to her nest mates.