Transpiration rate affected by stomatal blockage

Steps:

• Measure initial and final mass of each setup to calculate water loss.
• Petroleum jelly on leaves blocks stomata, reducing transpiration.
• Compare water loss: setups with jelly lose less water than those without.
• Identify setup B as having jelly on all leaves, minimizing mass loss.

Why B is correct:

• B shows least water loss, as jelly fully blocks stomata per transpiration definition (water vapor escape through stomata).

Why the others are wrong:

• A: No jelly, so full transpiration and highest water loss.
• C: Partial jelly, allowing some transpiration through unblocked areas.
• D: Jelly only on one side, permitting transpiration from the other.

Not enough information on exact diagram details.

Final answer: B