Practice question

Cryptobiosis denotes ametabolic dormant state triggered by extreme desiccation, freezing or osmolarity where metabolism becomes undetectably low and organism forms protective tun, cyst or coiled anhydrobiotic form rich in trehalose and LEA proteins forming biological glass. Tardigrades famously enter tun via anhydrobiosis, rotifers produce dormant resting eggs, many nematodes survive soil drying. Vertebrate fishes lack molecular machinery for intracellular vitrification, trehalose accumulation and reversible cytoskeletal stabilization; instead they rely on behavioral avoidance, migration or physiological tolerance like freeze-tolerant heart but not systemic suspended animation. Complex organ systems prevent true whole-body cryptobiosis.