Ch.1 The Conditions of Life on Earth

Question 1

When was the Earth formed?

Answer 1

4.6 billion years ago

Question 2

How was Earth formed?

Answer 2

By rock fragments in space pulled together through gravity

Question 3

What happened as the rocks joined during Earth’s formation?

Answer 3

Huge amounts of energy were absorbed, creating heat and producing a ball of molten rock

Question 4

What is produced when the surface of Earth cooled gradually?

Answer 4

A surface crust of solid rock

Question 5

List the 5 features of Earth that created suitable conditions for life.

Answer 5

• Distance from Sun: Earth orbits in the Goldilocks zone- which liquid water are allowed
• Mass: Earth’s mass generates enough gravitational pull to hold the life-sustaining atmosphere
• Axis of rotation: tilt causes seasonal variation, distributing solar energy evenly across
• Speed of rotation: temperature moderation- prevents one side from overheating & freezing
• Magnetic field: magnetosphere is generated from from molten outer core- deflecting solar wind & cosmic rays

Question 6

What is the significance of Earth’s location in the Goldilocks zone?

Answer 6

It allows for temperatures that permit liquid water

Question 7

What role does Earth’s mass play in supporting life?

Answer 7

It generates enough gravitational pull to hold the life-sustaining atmosphere

Question 8

What is the effect of Earth’s axial tilt?

Answer 8

It causes seasonal variations, distributing solar energy more evenly across the planet

Question 9

What is the speed of Earth’s rotation?

Answer 9

24-hour rotation cycle

Question 10

How does Earth’s rotation prevent extreme temperature swings?

Answer 10

It prevents one side from overheating and freezing

Question 11

What generates Earth’s magnetosphere?

Answer 11

The molten outer core

Question 12

What does the magnetosphere do?

Answer 12

Deflects harmful solar wind and cosmic rays

Question 13

True or False: The magnetosphere protects DNA and the atmosphere.

Answer 13

True

Question 14

What is essential as a solvent and transport medium for early life on Earth?

Answer 14

Liquid Water

Liquid water played a critical role in temperature regulation and nutrient transport, similar to functions in blood or sap.

Question 15

What unique property of water protects early marine life?

Answer 15

High heat capacity

This property helped stabilize aquatic habitats before the formation of the ozone layer.

Question 16

What temperature range did most regions on Earth stay within, allowing for liquid water?

Answer 16

0°C - 35°C

This range prevented protein denaturation, enabling life.

Question 17

Which gases were critical for protein synthesis in early Earth’s atmosphere?

Answer 17

Oxygen (O2) and nitrogen (N2)

These gases played a significant role in the development of life and were used in photosynthesis.

Question 18

What process used atmospheric gases to synthesize organic molecules?

Answer 18

Photosynthesis

Photosynthesis allowed the synthesis of lipids and carbohydrates, which are essential for life.

Question 19

What did the Miller-Urey experiment demonstrate?

Answer 19

Organic compounds could be synthesized from inorganic matter under certain conditions

The experiment showed that amino acids could form in a simulated early Earth environment.

Question 20

What role did solar energy play in early Earth conditions?

Answer 20

Regulated heat absorption

Solar energy, along with Earth’s albedo and atmospheric composition, influenced temperature regulation.

Question 21

Fill in the blank: _______ is critical for stabilizing aquatic habitats.

Answer 21

Liquid Water

Question 22

True or False: The high heat capacity of water contributed to the protection of early marine life.

Answer 22

True

Question 23

What is the significance of the temperature range of 0°C - 35°C for early life?

Answer 23

It allowed for liquid water and prevented protein denaturation.

Question 25

What gas formed as a result of photosynthetic Archaea, enabling terrestrial life?

Answer 25

Oxygen ## Footnote This process began with cyanobacteria releasing oxygen around 2.7 billion years ago.

Question 26

When did the Great Oxidation Event occur?

Answer 26

~ 2.45 billion years ago ## Footnote This event marked the time when surplus oxygen entered the atmosphere.

Question 27

What role did photosynthetic organisms play in the Earth's atmosphere?

Answer 27

They increased oxygen levels and sequestered carbon ## Footnote This process involved absorbing CO2 and stabilizing global temperatures.

Question 28

What are biogeochemical cycles?

Answer 28

Nutrient recycling processes ## Footnote Examples include carbon and nitrogen cycles, allowing ecosystems to thrive without resource depletion.

Question 29

What effect did land plants have on the environment?

Answer 29

They released water vapor and rainfall ## Footnote This enabled further colonization of terrestrial habitats.

Question 30

True or False: Anaerobic organisms thrived as oxygen levels increased.

Answer 30

False ## Footnote Anaerobic organisms declined as aerobic life forms, such as plants and animals, diversified.

Question 31

Fill in the blank: The process of _______ contributed to the stabilization of global temperatures by absorbing CO2.

Answer 31

photosynthesis ## Footnote Photosynthetic organisms play a crucial role in carbon sequestration.

Question 32

What is the significance of limestone in geological history?

Answer 32

It forms from ancient marine deposits and indicates past conditions ## Footnote Limestone is associated with the processes of carbon sequestration.

Question 33

How did oxygen levels affect the evolution of life on Earth?

Answer 33

They allowed for the diversification of aerobic life ## Footnote Increased oxygen levels led to the decline of anaerobic organisms.

Question 34

What was one consequence of the release of oxygen into the atmosphere?

Answer 34

It counteracted the sun's heat and enabled life to thrive ## Footnote This process contributed to the Great Oxidation Event.

Question 35

What are the two main types of organisms mentioned that played a role in changing Earth's environment?

Answer 35

Cyanobacteria and aerobic organisms ## Footnote Both contributed to the increase of oxygen in the atmosphere.