Water deficits can cause which of the following?

• A. Increased photosynthesis
• B. Ultraviolet damage with no effect
• C. Enhanced growth
• D. Slowed photosynthesis, stomatal closure and wilting leaves

Answer: (D)

When a tree lacks water, it closes its stomata to limit water loss. That stomatal closure also reduces the entry of carbon dioxide into the leaves, so photosynthesis slows down. With less photosynthesis, the tree’s energy and carbohydrate production drop, and growth is hindered. The loss of turgor pressure in leaf cells from the water deficit causes the leaves to wilt. This combination—slowed photosynthesis, stomatal closure, and wilting leaves—is the typical response to insufficient water.

The other ideas don’t fit because drought does not boost photosynthesis or growth; it reduces both as the tree conserves resources. Ultraviolet damage isn’t a direct, universal consequence of water deficit, and saying there’s no effect contradicts the stress drought puts on the plant.