Plant Water Conservation and Photosynthesis

The video explores factors affecting photosynthesis, such as light intensity, carbon dioxide, and temperature. It explains why root cells lack chloroplasts and the role of stomata in gas exchange and water conservation. The process of photorespiration is discussed, highlighting its impact on photosynthesis efficiency. Finally, alternative photosynthesis pathways like CAM and C4 are explored, focusing on plants like cacti, pineapples, corn, and sugarcane.

Which factor does NOT affect the rate of photosynthesis?

• Amount of water

• Light intensity

• Temperature

• Carbon dioxide levels

Why do root cells in plants lack chloroplasts?

• They have a different type of chlorophyll

• They are exposed to sunlight

• They are underground and do not receive sunlight

• They do not need to perform photosynthesis

What is the primary function of stomata in plants?

• To protect the plant from pests

• To absorb nutrients from the soil

• To facilitate gas exchange and water loss

• To store energy

What happens to the levels of carbon dioxide and oxygen when stomata close?

• Both carbon dioxide and oxygen levels increase

• Carbon dioxide levels increase, oxygen levels decrease

• Carbon dioxide levels decrease, oxygen levels increase

• Both carbon dioxide and oxygen levels decrease

What is photorespiration?

• A process where plants grow faster

• A process where plants absorb more sunlight

• A process where plants produce more sugar

• A process where plants use oxygen instead of carbon dioxide in the Calvin cycle

Which plants use the CAM pathway for photosynthesis?

• Corn and sugarcane

• Cacti and pineapples

• Wheat and rice

• Tomatoes and potatoes

How do CAM plants conserve water?

• By closing their stomata during the day

• By opening their stomata during the day

• By storing water in their leaves

• By growing in shaded areas

What is a characteristic of C4 plants?

• They open their stomata only at night

• They grow in cold environments

• They partially close their stomata during the hottest part of the day

• They require more water than other plants

Which of the following is a C4 plant?

• Corn

• Pineapple

• Rose

• Cactus

Why is the C4 pathway beneficial for plants like corn and sugarcane?

• It makes them resistant to pests

• It allows them to grow in colder climates

• It reduces their water requirement

• It increases their sugar production