Q.Organisms which can survive a wide range of temperature are called

Temperature governs metabolism, behaviour, reproduction, development and survival across all organisms, and several classical ecological rules describe how organisms and populations respond to it. Van't Hoff's rule holds that metabolic rate roughly doubles for every 10°C rise (and halves for every 10°C fall), a ratio expressed as the Q10 value, close to 2.0 in most living systems. Bergmann's rule notes that within a widely distributed group of related species, colder-region populations tend to be larger-bodied (better heat retention) than warmer-region populations. Allen's rule notes that warm-blooded animals in colder climates tend to have shorter limbs and extremities than relatives in warmer climates, again to conserve heat. Jordan's rule links colder water to a higher vertebral count in fish. Organisms are further classed by their temperature tolerance breadth: eurytherms tolerate a wide temperature range (an evolutionary advantage that aided survival through ice ages and colonisation of new habitats), while stenotherms — including many fish, frogs, lizards and snakes — tolerate only a narrow range. Extreme-temperature adaptations include heat-resistant spores/cysts, antifreeze proteins in Arctic fish, hibernation, aestivation, and migration.