Chapter 1 ! Flashcards
Features of Earth that created suitable conditions for life
Features of earth that created sustainable conditions for life
- Mass
- Distance from the sun,
- axis of rotation,
- speed of rotation
- magnetic field
Explain how the mass effects ability for life on earth to occur
Features of earth that created sustainable conditions for life
- Masss is great enough to prevent most gases escaping into space (which allowed the atmosphere to include C, H, O, N)
- atmospheric pressure must be high enough to prevent liquid water boiling
Explain how the distance from the sun effects the ability for life on earth to occur
Features of earth that created sustainable conditions for life
- light & distance from sun affects the suitable temperatures
- Too close / too far would prevent liquid water being present
- The time taken for the earth to rotate on the axis produces a day / night cycle fast enough to avoid excessive heating / cooling
what is the goldilocks zone ?
Features of earth that created sustainable conditions for life
the range of distance in space where temperature is suitable for water to remain in liquid form on the planet meaning life can be possible
how has the axis of rotation effected life on earth ?
Features of earth that created sustainable conditions for life
- axis prodcues seasonal variations as the earth orbits the sun
how has the speed of rotation effected life on earth ?
Features of earth that created sustainable conditions for life
- the 24 hour period rotation reduces extremes of heating or cooling
how does the magnetic field effect life on earth ?
Features of earth that created sustainable conditions for life
- it deflects solar wind & prevents biologically solar radiation reaching earths surface
what are 4 early conditions that allow life to develop ?
Development of life on earth
- presence of liquid water
- temperature range
- atmospheric gases
- solar insolation
how has the temperature range allowed early life to develop ?
Development of life on earth
- range is 0℃ - 35℃
- this range means most areas are warm enough for liquid water but not too hot to denature proteins
how has the atmospheric gases allowed early life to develop ?
Development of life on earth
- CO2 present allows photosynthesis
- N present allows protein synthesis
how has the solar insulation allowed early life to develop ?
Development of life on earth
- heat from sunlight provides energy that drives the water cycle and warms the surface
- composition of atmosphere : controls amount of infrared energy that is absorbed and converted into heat
what 4 things changed as life began to develop ?
How life on earth caused environmental change
- atmospheric oxygen
- carbon sequestration
- biogeochemical cycles
- transpiration
how has atmospheric oxygen changed as life began to develop ?
How life on earth caused environmental change
- Archaea (single celled organisms in the oceans) developed the ability to photosynthesize
- For millions of years, all the oxygen produced had reacted with iron in the oceans, once it was all gone the oxygen surplus built up and began being released into the atmosphere causing concentrations to rise
how did oxygen in the atmosphere make life possible ?
How life on earth caused environmental change
- Oxygen in atmosphere → absorbed uv light → made life on surface possible
how has carbon sequestration changed as life began to develop ?
How life on earth caused environmental change
- CO2 retains heat energy
- photosynthesis organisms absorbed CO2 (some stored in geological sediments)
- helped prevent temperature rise
