AP BIOLOGY

Detailed explanation-1: -When hibernating, an animal’s metabolism slows significantly: its heartbeat slows, it breathes more slowly (some animals even stop breathing for periods of over an hour) and its body temperature drops-in some extreme cases to below the freezing point of water (zero degrees Celsius).

Detailed explanation-2: -Hibernating animals slow their metabolisms, cooling their bodies by 5° to 10°C (9° to 18°F). Arctic ground squirrels (Spermophilus parryii) can take this much further, cooling their bodies to subfreezing temperatures.

Detailed explanation-3: -In hibernation, respiration consists of one to two deep sighs followed by apnea of variable duration, averaging 1–3 breaths/min. The heart rate is often arrhythmic, but averages 7–8 beats/min.

Detailed explanation-4: -Breathing rate drops by 50 percent to 100 percent. Yes, 100 percent. Some animals stop breathing entirely. A few reptiles go their entire hibernation period without breathing, and even mammals have shown the ability to survive with drastically reduced oxygen supplies.

Detailed explanation-5: -Hibernation is a hypothermic condition when animals save energy during cold seasons by lowering body temperature, metabolism, breathing, and heart rate. This makes it possible for an animal to survive the winter on a fat deposit that would not last the winter.