UPSC 2024 Environment and Ecology Questions with Answers

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.