The Evolution of Life on Earth

What was Earth's early atmosphere composed of?

• Methane and helium

• Water vapor and ash

• Oxygen and nitrogen

• Carbon dioxide and oxygen

Which molecules are thought to have been the first genetic material?

• DNA

• Proteins

• Lipids

• RNA

What significant change did photosynthesizing organisms bring to Earth's atmosphere?

• Increase in carbon dioxide

• Decrease in water vapor

• Decrease in nitrogen

• Increase in oxygen

What evidence suggests the oldest signs of life?

• Insect fossils

• Carbon molecules in rocks

• Human artifacts

• Dinosaur bones

What was a major consequence of the oxygen-rich atmosphere for early life forms?

• Poisoning many of them

• Increased size

• Development of photosynthesis

• Improved mobility

Which adaptation is NOT mentioned as contributing to survival and reproduction?

• Claws in hunters

• Hard shells in prey

• Legs and lungs in fish-like animals

• Wings for flight

What did Dr. Meemann Chang discover about fish fossils?

• They could walk on land

• They had inner and outer nostrils

• They had a pair of nostrils between front teeth

• They had wings

What drives macroevolution according to the video?

• Solar flares

• Human activities

• Meteor impacts only

• Plate tectonics and climate changes

How many times have mass extinctions occurred in Earth's history?

• Ten times

• Three times

• Five times

• Seven times

What is the relationship between life and Earth's changing conditions described as?

• A symbiotic relationship

• A competition

• A dance

• A battle for survival