Conditions For Life On Earth Flashcards
Why is the mass of the earth significant?
Mass of earth and force of gravity allows us to retain an atmosphere with vital gasses present.
Why is the earths rotation and tilt on its axis significant?
Rotation and tilt on its axis and orbit around the sun control the earths seasonal and daily temperature range.
Why is the earths molten core significant?
Molten core produces a magnetic field which deflects solar wind
How did oxygen become present in the earths atmosphere?
First by photosynthetic bacteria, then by plants and algae release oxygen during photosynthesis
How was the ozone layer formed and why is it significant?
By chemical reactions involving oxygen and uv light. Absorbs uv radiation so that it doesn’t harm organisms.
Why is the earths high atmospheric pressure significant for life on earth?
Allows presence of liquid water
Why is appropriate temp range vital for presence of life on earth?
Allows efficient enzyme reactions In organisms
What are some improved methods for monitoring the conditions of life on earth?
Use of electronic monitoring equipment
Gas analysis of ice cores
Improved carriers of monitoring equipment eg satellites
Collection of long term data sets
Despite a 30 percent increase in solar radiation, temperatures on earth have not shown a large a large increase, why is that?
Co2 levels have reduced in photosynthesis
Co2 is a greenhouse gas that absorbs IR
How have oxygen concentration increase allowed the presence of organisms possible on earth?
Excess oxygen levels lead to formation of ozone in the stratosphere which absorbs uv light
Fewer mutations/DNA damage allowed organisms to evolve
How is solar insolation vital for life on earth?
Sunlight absorbed by low albedo objects on earths surface
This is re emitted by the earth as infrared and absorbed by atmospheric gases
Energy for photosynthesis
