Environment and Ecology Mixed Practice — MCQs with Answers (Set 24)

When Australia broke from Antarctica around 35 million years ago, its resident marsupials faced no placental competition and radiated into the continent’s many niches.

India’s collision with Asia gave placental mammals a land route in — marsupials had already missed their only dispersal window, tens of millions of years earlier.

South America stayed linked to Australia through Antarctica, which was much warmer then. Marsupials spread across all three southern continents through this route.

India split from Madagascar around 80 million years ago, well before marsupials had even evolved.

Statement-I is correct: marsupials aren’t naturally found in India. India split from Madagascar around 80 million years ago, before marsupials had even evolved (~100 mya, likely in South America), so it missed the southern dispersal route through Antarctica to Australia. Statement-II is wrong: marsupials thrive in many habitats worldwide, from Australian deserts to South American forests, and coexist with natural predators like dingoes.

Shedding leaves in the dry season reduces water loss through transpiration, helping the tree conserve moisture when water is scarce.

Jackfruit is the national fruit of Bangladesh, and is also widely cultivated across India and Southeast Asia.

Mahua flowers are used to make food and traditional alcoholic drinks, and its seeds yield edible oil, making it economically important.

Teak’s natural durability and resistance to rot and pests makes it especially valuable for shipbuilding, furniture, and construction.

Most of the oxygen phytoplankton produce escapes into the atmosphere, while respiration and decomposition in the ocean use up roughly as much oxygen as photosynthesis creates.

Prochlorococcus, a genus of tiny marine cyanobacteria, is thought to produce up to a fifth of all oxygen in the biosphere by itself.

Well-oxygenated surface water holds far less oxygen than air (roughly 8–11 mg/L dissolved, versus about 21% oxygen by volume in air), because of oxygen’s limited solubility in water.

A mature rainforest’s net oxygen output is close to zero, because its own animals, microbes, and decomposition consume roughly as much oxygen as its plants produce.

The survey is being conducted in the Nagarjunasagar-Srisailam Tiger Reserve, part of the Nallamala Hills, in collaboration with the Eastern Ghats Wildlife Society.

The IUCN classifies the Gooty tarantula as Critically Endangered, threatened by habitat destruction and the illegal exotic-pet trade.

In its natural habitat, the Gooty tarantula is an arboreal species, living in tree holes and bark crevices rather than burrowing underground.

Its natural habitat in India is limited to only a small area of forest around Gooty, Andhra Pradesh, making it highly vulnerable to habitat loss.

The Gooty tarantula (Poecilotheria metallica) is a spider — an arachnid — not a crustacean.

Captured CO2 can be combined with hydrogen to produce synthetic low-carbon fuel, a pathway explored as a way to cut aviation emissions.

DAC must extract CO2 from air where it makes up only about 0.04% (roughly 400 parts per million), far more dilute than an industrial flue-gas stream, making it energy-intensive and costly.

DACCU stands for Direct Air Carbon Capture and Utilization — DAC paired with converting the captured CO2 into fuel or products, as distinct from DACCS (storage).

Climeworks, a Swiss company founded in 2009, is one of the best-known commercial DAC operators, running large-scale plants including one in Iceland.

DAC extracts carbon dioxide directly from the ambient atmosphere, unlike conventional carbon capture, which pulls CO2 from a concentrated industrial source like a power-plant flue.

An MBR membrane’s small pore size removes suspended solids, bacteria, and even some viruses, producing effluent of high enough quality for reuse in irrigation or industrial processes.