Advanced Science Primary 5 Systems

Alexa cut the outer ring of a plant stem, removing the food-carrying tubes but leaving the water-carrying tubes intact. After a week, what will she observe?

A The roots will grow longer and thicker.
B The leaves above the cut will turn yellow and die immediately.
C The stem above the cut will swell.
D The whole plant will die within a day.
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Worked Solution

Step 1: The food-carrying tubes transport food from the leaves downwards to the roots. Step 2: Removing the outer ring breaks this transport path. Step 3: Food made by the leaves accumulates just above the cut, causing the stem to swell.

Correct answer: The stem above the cut will swell.

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