Biology (40: Water and Electrolyte Balance)

One of the waste products that accumulates during cellular functions is carbon dioxide. It is removed via the respiratory system. What other waste product(s) accumulate during normal physiological functions in vertebrates?

I. ammonia II. uric acid III. urea

Which of the following is true of osmosis? In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration. Osmosis only takes place in red blood cells. Osmosis is an energy-demanding, or "active" process. In osmosis, solutes move across a membrane from areas of lower water concentration to areas of higher water concentration. In osmosis, water moves across a membrane from areas of higher solute concentration to areas of lower solute concentration.

In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration.

Which of the following affects the osmolarity of a solution? I) Concentrations of cations II) Concentrations of anions III) Concentration of water

Only I and II

When a cell is in equilibrium with its environment which of the following occurs for substances that can diffuse through the cell membrane? There is no movement of substances into or out of the cell. There is random movement of substances into or out of the cell. There is directed movement of substances into and out of the cell. All movement of molecules is performed by active transport. Water is moved against its gradient.

There is random movement of substances into or out of the cell.

Under what circumstances does membrane transport require energy?

Whenever a solute is moved against its electrochemical gradient.

If you are hiking through the desert for several days, which of the following should you drink to ensure proper hydration?

a drink with a combination of water and electrolytes

Identify the three regions in the loop of Henle in the correct order that filtrate passes through the loop.

descending limb, thin ascending limb, thick ascending limb

Biologists have been able to produce mice that lack functional genes for aquaporins. How would the urine of these mice compare to that of mice with normal aquaporins?

higher volume and lower osmolarity

Which structure in the mammalian kidney is responsible for maintaining the osmotic gradient in medulla of the kidney?

loop of Henle

In terrestrial vertebrates, selective filtration of nutrients back to the blood beings in the ___________ of the nephron.

proximal tubule

In terrestrial vertebrates, urine formation begins in the __________ of the nephron.

renal corpuscle

The force driving simple diffusion is ________, while the energy source for active transport is ________.

the concentration gradient; ATP