Ch 25.

Question 1

Describe the history of the Earth

Answer 1

The Earth formed over 4.6 billion years ago out of a mixture of dust and gas around the young sun. It grew larger thanks to countless collisions between dust particles, asteroids

Question 2

Understand the relationship between geological events and the evolution of life

Answer 2

• Warm water = evolution of life. e.g oceans edge, hot springs, deep sea vents etc
• Chemical molecules in oceans derived from rain + energy from heat (e.g techtonic plates moving) created opportunities for cell development
• RNA developed which is considered the basis of all life

Question 3

Contrast today’s atmosphere with the likely atmosphere at the end of the Hadean eon.

Answer 3

• By the end of the Hadeon period, the temperature was around 55-85°C, which is at least 40°C hotter than the current average surface temperature.

Question 4

Describe the key steps necessary for life to originate

Answer 4

1. An abiotic (non-living) synthesis of Amino Acids and Nucleic Acids must occur.
2. The RNA/DNA molecules form and gain the ability to reproduce
3. The evolution membrane of phospholipids and proteins to keep the cell intact.

Question 5

Evaluate the strength of fossil evidence dating the origins of life.

Answer 5

• Micro fossil dating 3.2 billion years old and resembles present day prekaryotes
• fossil life indicates that life started in the Archean period

Question 6

Explain the relationship between CO2 levels and glaciation simple

Answer 6

When CO₂ levels go up, the atmosphere traps more heat, and the Earth gets warmer, causing glaciers and ice sheets to shrink or melt.
Low CO₂ → Cooler climate → More glaciation
High CO₂ → Warmer climate → Less glaciation

Question 7

Describe how plate tectonics has affected the evolution of life on Earth

Answer 7

Changed the climate
Formed mountains and volcanoes
Separated or connected continents

Question 8

Compare and contrast the evolution of the endomembrane system and mitochondria
and chloroplasts

Answer 8

All are found in eukaryotic cells.
All help the cell function better by processing energy or materials.
how they evolved and what they do are different.

Question 9

Describe the types of cell specialization needed for multicellularity

Answer 9

organisms need cells to specialize—each type of cell does a specific job to help the whole organism survive.