Natural Cycles: Oxygen and Carbon Cycle

The video explains the essential role of oxygen for animals and how plants replenish it. It describes the process of photosynthesis, where plants take in carbon dioxide and release oxygen. The video also covers how animals obtain energy from carbohydrates, producing carbon dioxide as a byproduct, which plants then use, completing the cycle.

What percentage of the air is made up of oxygen?

• 30%

• 21%

• 50%

• 15%

Which organisms are responsible for replenishing oxygen in the atmosphere?

• Animals

• Plants and algae

• Bacteria

• Fungi

What gas do plants absorb from the atmosphere?

• Carbon dioxide

• Hydrogen

• Nitrogen

• Oxygen

What is a byproduct of energy production in animals?

• Water

• Carbon dioxide

• Oxygen

• Nitrogen

How do animals primarily obtain energy?

• By consuming carbohydrates

• By breathing in oxygen

• By absorbing sunlight

• Through photosynthesis