Translocation moves nutrients in phloem of plant stems

Steps:

• Identify region Z as phloem tissue in the stem diagram.
• Recall phloem transports organic substances like sugars from leaves to other parts.
• Link this to translocation, the active process for long-distance sugar movement.
• Rule out other options as they don't fit phloem's role.

Why C is correct:

• Translocation is the mass flow of sugars and nutrients through phloem sieve tubes, driven by pressure gradients from source to sink.

Why the others are wrong:

• A: Diffusion is passive movement of molecules over short distances, not for bulk transport in stems.
• B: Osmosis is water movement across membranes, not substance transport in vascular tissue.
• D: Transpiration drives water and mineral uptake via xylem, not nutrient movement in phloem.

Final answer: C