Question

which of the following is not a passive process of movement? a solute pumps b osmosis c facilitated diffusion d diffusion

Explanation:

1. Recall the definitions of passive and active transport: Passive processes (like osmosis, facilitated diffusion, diffusion) do not require energy and move substances down their concentration gradient. Active processes require energy (ATP) and move substances against the gradient.
2. Analyze each option:

• Option B (Osmosis): Movement of water across a semi - permeable membrane, passive (no energy needed).
• Option C (Facilitated diffusion): Movement of substances with the help of transport proteins, down the concentration gradient, passive.
• Option D (Diffusion): Movement of substances from high to low concentration, passive.
• Option A (Solute pumps): These are involved in active transport, as they use energy (e.g., ATP) to move solutes against their concentration gradient. So solute pumps are not a passive process.

Answer:

A. Solute pumps