At a particular position along a nephron, the osmotic potential of the filtrate is 500 mOsm/L, whereas the surrounding kidney's is 600 mOsm/L. Which of the following is a likely result?

• A. Water will diffuse into the nephron by osmosis.
• B. Water will be pumped into the nephron by active transport.
• C. Water will be pumped out of the nephron by active transport.
• D. There will be no net movement of water.
• E. Water will diffuse out of the nephron by osmosis.

Answer: (E)

Verified step by step guidance

1. Understand the concept of osmosis: Osmosis is the movement of water across a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration.
2. Identify the osmotic potential of the filtrate and the surrounding kidney: The filtrate has an osmotic potential of 500 mOsm/L, and the surrounding kidney has an osmotic potential of 600 mOsm/L.
3. Determine the direction of water movement: Since the surrounding kidney has a higher osmotic potential (600 mOsm/L) compared to the filtrate (500 mOsm/L), water will move from the filtrate into the surrounding kidney.
4. Conclude the type of transport: The movement of water in this scenario is due to osmosis, which is a passive process, meaning water will diffuse out of the nephron.
5. Eliminate incorrect options: Active transport involves energy expenditure, which is not applicable here. Therefore, options involving active transport can be ruled out, and the correct result is that water will diffuse out of the nephron by osmosis.