Pigmentation of the skin results from the accumulation of melanin-containing melanosomes in the basal layer of the epidermis. Differences in skin pigmentation result both from the relative ratio of eumelanin (brown–black) to pheomelanin (yellow–red), as well as the number of melanosomes within melanocytes.
Skin cells will produce more melanin, replacing what has been lost and increasing the percentage of melanin in the skin. This melanin has two effects, acting as a barrier to protect the skin from further damage, and darkening the natural color of the skin.
Any time a body is in an environment that is colder than 98.6 F (37 C), heat is lost. And since the heat loss in water is 25 times faster than to air, this may occur fairly quickly.
The shivering on a cold day is the body's mode of heat generation.This is a negative feedback mechanism where a change is detected by the body'd internal environment and crafts a mechanism to correct it
Explanation: this makes the most sense bc the duck has a visual adaptation meaning it is a physical adaptation so the top two are wrong, d doesn't have anything to do with food.
