Early Life and Earth's Atmosphere

What was Earth like before life existed?

• Covered in forests and rivers

• Mostly hot rock and salty water

• Filled with dinosaurs and volcanoes

• A cold, icy planet

What was the atmosphere like on Earth before life began?

• Full of oxygen and clean air

• Mostly nitrogen and water vapor

• Filled with poison gas and no oxygen

• Protected by a thick ozone layer

What was the first type of life to form on Earth, and where did it mostly live?

• Dinosaurs, on land

• Fish, in rivers

• Bacteria, in the ocean

• Birds, in the sky

What process did early ocean bacteria use to remove carbon dioxide from the air?

• Respiration

• Photosynthesis

• Digestion

• Fermentation

What type of plants were the very first land plants?

• Ferns

• Bryophytes

• Flowering plants

• Conifers

In which country were the fossils of the first land plants found?

• England

• Scotland

• Ireland

• Wales

Why did the first land plants need to grow close to water?

• They needed water to attract insects.

• They lacked special tissues to move and store water.

• They used water to protect themselves from animals.

• They could only get sunlight near water.