Some ions and molecules need the cell to use energy to allow them to cross the cell membrane. this type of transport is called a) osmosis b) diffusion c) active transport d) passive transport

you are the source of the heat energy. you can minimize the heat energy by selecting the appropriate clothes to wear.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands