Question

1. why it is necessary for plants to have chloroplasts?
2. the central vacuole stores water. what would happen to the size of the central vacuole if a plant does not have enough water?
3. how do you think the vacuole would be different if the plant was well - watered?
4. why do you think a plant has both a rigid cell wall and a cell membrane?

Explanation:

1. Chloroplasts are the sites of photosynthesis in plants. They contain chlorophyll which captures light - energy to convert carbon dioxide and water into glucose and oxygen. So plants need chloroplasts to produce food and oxygen for their survival and growth.
2. If a plant does not have enough water, the central vacuole will shrink in size. This is because water is released from the vacuole to maintain other cellular functions, and without replenishment, its volume decreases.
3. If the plant is well - watered, the central vacuole will be large and turgid. It will be filled with water, providing structural support to the plant cell and helping the plant maintain an upright posture.
4. The rigid cell wall provides structural support and protection to the plant cell, helping the plant maintain its shape and withstand mechanical stress. The cell membrane is a semi - permeable barrier that controls the movement of substances in and out of the cell, regulating the cell's internal environment. Both are necessary for the proper functioning and survival of the plant cell.

Answer:

1. Chloroplasts are needed for photosynthesis to produce food and oxygen.
2. The central vacuole will shrink.
3. The central vacuole will be large and turgid.
4. The cell wall provides support and protection, while the cell membrane regulates substance movement.