Photosynthesis: Variations in Photosynthesis

The video discusses the process of photorespiration, which affects the Calvin cycle by fixing oxygen instead of carbon dioxide, leading to carbon loss. This is exacerbated in warm climates due to stomatal closure. C4 plants, like corn and sugarcane, have developed a mechanism to efficiently fix CO2, despite higher ATP costs. CAM plants, such as cacti, adapt by storing CO2 at night. Additionally, photosynthesis is not limited to plants; many protists and bacteria also contribute significantly to the world's oxygen supply.

What is the main reason for the increase in photorespiration in warm climates?

• Higher oxygen levels

• Closure of stomates to conserve water

• Increased sunlight

• Lack of nutrients

How do C4 plants like corn and sugarcane improve the efficiency of the Calvin cycle?

• By reducing ATP consumption

• By using an extra photosynthetic pathway

• By opening stomates at night

• By using less water

What is a significant drawback of the C4 pathway in plants?

• It requires more water

• It needs more ATP

• It reduces glucose production

• It limits oxygen release

How do CAM plants adapt to their hot, dry environments?

• By reducing leaf size

• By taking in CO2 at night

• By opening stomates during the day

• By storing water in leaves

Besides plants, which other organisms are known to perform photosynthesis?

• Fungi and algae

• Protists and bacteria

• Viruses and fungi

• Algae and viruses