What process do plants use to make oxygen?

• Respiration

• Transpiration

• Photosynthesis

• Fermentation

What do animals do with the oxygen they breathe in?

• Animals convert oxygen into carbon dioxide for breathing.

• Animals use oxygen for cellular respiration to produce energy.

• Animals exhale oxygen as waste.

• Animals use oxygen to build muscle mass.

Why are plants important for the oxygen cycle?

• Plants produce oxygen through photosynthesis, making them important for the oxygen cycle.

• Plants release carbon dioxide, which is essential for the oxygen cycle.

• Plants absorb oxygen during photosynthesis, reducing oxygen levels.

• Plants do not play a role in the oxygen cycle at all.

Where is most of the oxygen found in our environment?

• In the Earth's atmosphere.

• In the Earth's core.

• In the Earth's crust.

• In the Earth's oceans.

What is the first stage of the oxygen cycle?

• Respiration

• Photosynthesis

• Decomposition

• Combustion

How do humans contribute to the oxygen cycle?

• Humans do not affect the oxygen cycle at all.

• Humans produce oxygen through photosynthesis.

• Humans only consume oxygen without any contribution.

• Humans contribute to the oxygen cycle by respiring oxygen and supporting plant life that produces oxygen.

What gas do plants take in during photosynthesis?

• Hydrogen

• Carbon dioxide

• Nitrogen

• Oxygen

What do we call the process of breathing in and out?

• Exhalation

• Respiration

• Inhalation

• Ventilation

How does oxygen get back into the atmosphere?

• Oxygen is generated through the process of respiration.

• Oxygen is released during volcanic eruptions.

• Oxygen returns to the atmosphere mainly through photosynthesis.

• Oxygen is produced by burning fossil fuels.

What role do trees play in producing oxygen?

• Trees produce oxygen only at night.

• Trees produce oxygen through photosynthesis.

• Trees absorb carbon dioxide and release nitrogen.

• Trees do not contribute to the oxygen cycle.