Answer: the capillaries.
<span>The blood capillaries are blood vessels with very small caliber. They form the blood distribution and collection network in cells. They are the communication between branches
originating from the arteries and with the smaller
veins. It is on the walls of the capillaries that occurs <span>the exchange of water, oxygen, CO2,
other nutrients and chemical residues.</span></span>
Answer:
the pH
Explanation:
The condition that should not be kept the same in each of the five test tubes is the pH.
Since <u>the aim of the experiment is to investigate the effect of pH on the activity of the lipase enzyme</u>, the pH is, therefore, the <em>independent variable</em>. Thus, it must be controlled or varied in all the test tubes in order to see its effect on the activity of the enzyme, which, in this case, would be the dependent variable.
The part of the phospholipid bilayer that interacts with water would be the hydrophilic portion consisting of the polar phosphate group. The hydrophobic tails which are the fatty acid chains will not interact with the water present in the aqueous environment.
<span>At the base of Arthropoda.</span>
