Final answer:
The symptom of lack of water for a plant is leaves that are curling and yellowish in color.
Step-by-step explanation:
One of the symptoms of lack of water for a plant is leaves that are curling and yellowish in color. When a plant doesn't receive enough water, it can't perform photosynthesis properly, causing the leaves to curl and turn yellow. This is because water is essential for transporting nutrients and maintaining turgidity in plant cells.
Additionally, rigid and firm stems and leaves are not typically a symptom of lack of water. When a plant lacks water, it becomes wilted and the stems and leaves become limp and droopy.
Therefore, the correct symptom of lack of water for a plant is leaves that are curling and yellowish in color.
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