The independent variable of an experiment is the one that is intentionally changed or manipulated to see the results of changing said variable.
We are told that in each different group, the amount of caffeine that is given to the dogs changes - in the control group, they get no caffeine, in the 2nd group, they get 10 mg of caffeine each, and in the 3rd group, they get 50 mg of caffeine each.
Therefore, since the amount of caffeine that is given to the dogs is the only variable that is being manipulated, this is the independent variable.
Answer:
Take consistent amounts of their saliva samples with varying amounts of starch . (A.)
Oxygen is a small molecule and it's nonpolar, so it easily passes through a cell membrane. Carbon dioxide, the byproduct of cell respiration, is small enough to readily diffuse out of a cell. Small uncharged lipid molecules can pass through the lipid innards of the membrane.
The fact that choanoflagellates and collar cells of sponges resemble each other support the inference that chonoflagellates and sponges are sister groups.
Choanoflagellate are single -celled aquatic flagellate with single flagellum surrounded by a collar of microvilli. In addition choanoflagellate have a long interested evolutionary biologist due to their striking resemblance to collared cells of sponge.
