Biology · Organisms and Populations · NEET
A regulator keeps its internal body constant (constant temperature and osmotic concentration) even when the outside changes. All birds and mammals, and a few lower vertebrates and invertebrates, are regulators; humans keep body temperature near 37 C. A conformer lets its internal body change along with the environment. About 99% of animals and nearly all plants are conformers, so their body temperature or osmotic concentration rises and falls with the surroundings.
Yes. NCERT clearly states that all birds and mammals, and a very few lower vertebrates and invertebrates, are capable of thermoregulation and osmoregulation. This is a favourite one-line fact for NEET, so remember: birds and mammals = regulators (thermoregulation + osmoregulation).
Hibernation is Suspend (dormancy), not Regulate. When conditions become too harsh, some organisms escape in time by becoming inactive. A bear hibernating in winter and a snail or fish going into aestivation in summer are examples of the Suspend strategy. They lower their metabolism and wait out the bad season instead of keeping their body active.
Many organisms are partial regulators: they can regulate their body only within a narrow (limited) range of environmental conditions, and beyond that range they behave like conformers. So most species are not perfect regulators; they regulate up to a point and then let the internal state change with the environment.
Nearly all plants and about 99% of animals are conformers. Plants cannot maintain a constant internal temperature and largely let their internal conditions follow the environment. Regulation (true thermoregulation and osmoregulation) is mainly seen in birds and mammals, which is why regulators are the exception, not the rule.
Thermoregulation is energetically expensive. A small animal like a shrew or a hummingbird has a large surface area relative to its volume, so it loses body heat very fast and must spend a lot of energy to generate heat and stay warm. This is why very small animals are rarely found in polar regions; the cost of regulating body heat there is too high.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Regulate (keep internal body constant), Conform (let internal body change with the environment), Migrate (move temporarily to a less stressful place), and Suspend (become dormant or inactive, like hibernation, aestivation, diapause or seed dormancy).
Regulate: humans and birds keeping constant body temperature. Conform: most fish and frogs whose body temperature changes with water. Migrate: birds like the Siberian crane flying to Keoladeo (Bharatpur) in winter. Suspend: a bear hibernating, a snail aestivating, or a seed remaining dormant until conditions improve.
All three are forms of Suspend (escaping stress in time by becoming inactive). Hibernation is winter dormancy (e.g. bears), aestivation is summer dormancy to avoid heat and drought (e.g. some snails and fish), and diapause is a stage of suspended development seen in many zooplankton species under unfavourable conditions.
Forming thick-walled spores is a Suspend strategy. Under unfavourable conditions many bacteria, fungi and lower plants form thick-walled spores that stay dormant and resist stress; they germinate again when conditions become suitable, helping the organism survive time periods of harsh abiotic stress.
No. In Migrate the organism moves away in space to a more favourable habitat and returns when conditions improve. In Suspend the organism stays in place but escapes in time by lowering its activity and metabolism (dormancy). Both avoid stress, but one moves and one waits.
