[2026] PTE Academic Reading - Multiple Choice, Multiple Answers

Tardigrades, colloquially known as water bears, are microscopic, eight-legged animals famous for their extraordinary resilience.First described by a German zoologist in 1773, these resilient creatures can be found in almost every terrestrial and marine environment on Earth.They typically inhabit the thin layers of water that coat mosses, lichens, and leaf litter, feeding on plant cells, algae, and small invertebrates.

What truly distinguishes tardigrades is their ability to survive extreme conditions that would be fatal to almost all other known forms of life.When faced with environmental stress, such as severe dehydration or freezing temperatures, they enter a state of suspended animation called cryptobiosis.In this state, their metabolism drops to less than one percent of normal, and they curl up into a dehydrated ball known as a tun.

While in the tun state, tardigrades can withstand boiling liquids, massive doses of radiation, and even the vacuum of outer space.They survive these extremes by replacing the water in their cells with a sugar called trehalose, which prevents the crystallization of cell components.Once favorable conditions return, they rehydrate and resume their normal biological activities within a matter of minutes to a few hours.