Conditions For Life On Earth

Question 1

Features of earth that created suitable conditions for life

Answer 1

Mass
Distance from sun
Axis of rotation
Speed of rotation
Magnetic field

Question 2

Early conditions on earth that allowed life to develop

Answer 2

Presence of liquid
Temperature range
Atmospheric gases
Solar insulation

Question 3

Presence of atmosphere

Answer 3

1. Large mass and gravitational pull which keeps the atmosphere close
2. Contains important gases: CO2, N2 AND CH4
3. Temperature and pressure means water is in liquid form

Question 4

Solar Insulation

Answer 4

Suitable temperature range for enzyme action and water in liquid state
Provides energy for photosynthesis
Amount absorbed depends upon the albedo of the surface

Question 5

Position in the solar system

Answer 5

1. 3rd rock from the sun
2. Temperature warm enough for enzyme action

Question 6

Earth orbital behaviour

Answer 6

1. Rotation and tilt of the earth on its axis and its orbit around the sun
2. Controls daily and seasonal variations in isolation and temperatures
3. Enough day length to stop temperature extremes and light for photosynthesis

Question 7

Presence of the magnetosphere

Answer 7

Provides protection from solar radiation
Produced by the movement of earths molten core

Question 8

Presence of liquid water

Answer 8

Solvent water
Transport within organisms
Temperature controls
Anomalous expansion on freezing (most dense at 4°C)
High specific heat capacity
Aquatic habitats
Absorption of UV radiation

Question 9

Temperature range

Answer 9

Temperatures between 0°-35°

Question 10

Atmospheric gases

Answer 10

Carbon dioxide for photosynthesis and the synthesis of carbohydrates, proteins and lipids
Nitrogen for protein synthesis

Question 11

How life on earth caused environmental change

Answer 11

Atmospheric oxygen
Carbon sequestration by photosynthetic organisms
Biogeochemical
Transpiration

Question 12

Limitations of early methods

Answer 12

• Lack of ancient historical data.
• Limited reliability of proxy data for ancient conditions.
• Limited coordination between researchers.
• Lack of sophisticated equipment for accurate measurements.
• Inability to measure many factors.
• Lack of data collection in many areas.
• Reliance on proxy data, eg dendrochronology, pollen analysis.

Question 13

Improved methods

Answer 13

• Collection of long-term data sets.
• The use of electronic monitoring equipment.
• Gas analysis of ice cores.
• Isotope analysis of ice cores.
• Improved carriers for monitoring equipment, eg helium balloons, aircraft, satellites.