1) the temperature is nearly uniform throughout a lake
a. during winter when the ice forms an insulating cover.
b. during summer when the sunlight warms the surface and the wind mixes the layers.
c. by the end of the fall and spring overturn.
d. at all times due to winds causing constant mixing of the layers.
e. never. the lake always has different temperature layers and they are reversed in winter
and summer.
2) when trying to stimulate breathing, it is better to give a mixture of carbon dioxide
and oxygen than only oxygen because
a. pure oxygen causes you to breathe too rapidly.
b. carbon dioxide and oxygen together exert a greater pressure than an
c. carbon dioxide buildup in the blood stimulates the respiratory center in the brain.
d. oxygen causes lactic acid buildup, and the change in ph prevents breathing.
e. oxygen alone could lead to spontaneous human combustion.
3) the process by which cholesterol is transported into the cell by the binding of ldl to
its receptor and the internalization of the receptor-ldl complex is
a. facilitated transport.
b. active transport.
c. cotransport.
d. endocytosis.
e. exocytosis.
4) which association between zone and description is not correct?
a. littoral – lake zone closest to shore
b. benthic – stream, lake, or ocean floor
c. limnetic – lake zone on surface away from shore
d. bathypelagic – sunlit portion of the ocean