BIOL 1902 Lecture Notes - Lecture 5: Subcutaneous Tissue, Ectotherm, Antifreeze Protein
24 Oct 2018
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Document Summary
Subzero temps: ectotherms: an animal whose internal body temp is controlled by the temp surrounding it rely on external temperatures for body temp. Turtles, frogs, snakes, insects (cold blooded: endotherms: generate heat internally. Putting on extra layers on the outside: mammals guard hair: extra hair on outside, undercoat for extra warmth. Moose they grow dense fur called underfur inner coat: birds contour feathers on the outside become bulkier by 50% down feathers underneath. Colour can provide warmth: white- pale colours (fur/feathers) retain internal-heat better when there is windshield weather (snowy owls, glogers"s rule- further north you go, the lighter the fur. Snowshoe hares gain 27% in the coats insulation value. Large ears, legs, tail is not good (loose heat faster: alle(cid:374)"s rule- shorter extremities are better, berg(cid:373)a(cid:374)(cid:374)"s rule- low surface area: volume ratio body size is large in cold climates and small in warm climates (moose) Closer to 1 to 1 ratio is better.
