Conditions for life on earth Flashcards
What is the water sphere called?
Hydrosphere
What is the gas sphere called
Atmosphere
What is the rock sphere called
Lithosphere
What is the life sphere called
Biosphere
What is sufficient Thor the earth to retain an atmosphere
The mass of earth and it’s resulting force of gravity
Which gases did the early atmosphere provide for making biological molecules
Carbon Dioxide, methane and nitrogen
Where did these early atmosphere gases come from
Volcanic activity
What maintained liquid water
Atmospheric pressure and temperature
What is atmospheric pressure
The pressure exerted by the weight of the atmosphere
What would happen to water if atmospheric pressure was too low
Liquid water would boil well below 100 degrees
What would happen to water if the temperature was too low
Liquid water would turn to ice
What would happen to water if the temperature was too high
It would turn to gas
Why is liquid water important
It’s essential for life - physiological solvent, transport, coolant and it provides aquatic habitats
What does physiological solvent mean
Dissolving chemicals to allow biological reactions in solutions to occur
What is a coolant
Eg. Sweating
What is anomalous expansion
Where water expands instead of contracting when the temperature goes from 4 degrees to 0 degrees and it becomes less dense
What does anomalous expansion on freezing water create
An insulating later that prevents many water bodies from freezing solid
What is a specific heat capacity
The amount of energy needed to change the temperature of 1kg of the substance by 1 degree
What does high specific heat capacity of water mean
That water bodies change temperature slowly, creating more stable habitats
What is the amount of solar energy reaching a certain area called
Insolation
What is a suitable temperature range controlled by
Incoming insolation, it’s absorption by the earth’s surface and it’s behaviour in the atmosphere
What is the measure of the ability of surface to reflect light called
Albedo
What does a surface need to do to heat up
Absorb lots of energy
Why does ice have a cooling effect on the earth’s climate
Because it has a high albedo and reflects a great deal of solar energy without absorbing it
Why do darker surfaces have a low albedo
Because they reflect little sunlight and absorb most of it
What happens to some of the energy when sunlight is absorbed
It’s reradiated as longer wavelength radiation
Which type of radiation is reradiated
Infrared
What is the greenhouse effect
When infrared is absorbed by greenhouse gases in the atmosphere causing the atmosphere to heat up (because infrared has a heating effect on its surroundings)
Name 2 common greenhouse gases
Carbon dioxide and methane
Why does infrared heat
Because of its long wavelength
How do greenhouse gases absorb infrared radiation
As vibrations of their chemical bonds — when co2 vibrates it radiates infrared in all directions
How was the earth formed
By colliding roasting rocks
Without the greenhouse effect what degree would the earth be
-18 degrees
How far is the earth from the sun
150 million kilometres
What part of the solar system is the earth in concerning distance form the sun
The Goldilocks zone
What are enzymes
Proteins that speed up biological reactions: biological catalysts
What happens to enzymes when it gets too hot
They denature (unfold and permanently stop working)
What results in seasons
Earth’s tilted axis as earth orbits the sun, so different hemispheres receive more intense radiation per unit area at different locations around the sun
What keeps the earth from wobbling too much on its axis
The gravitational attraction from the moon
What provides the earth protection from radiation
The magnetosphere
What produces the magnetosphere
Earths molten outer core
How does the magnetosphere protect the earth
It deflects harmful solar radiation called solar wind
What would happen if we didn’t have a magnetosphere
The solar wind would blow away our atmosphere and would harm life
What does the term biota mean
Refers to living organisms in the area, they have a significant impact on the earths environment
How was oxygen first produced
From photosynthesis of bacteria and then algae and plants
What is photolysis
When energy from sunlight is used to plug water into hydrogen and oxygen
What is a photoautotroph
Photosynthetic organisms
What is respiration
A process by which energy can be released form sugars to allow organisms to power chemical reactions for survival
What type of respiration was around W fire oxygen was present in the air
Anaerobic, so no oxygen was needed
Which type of respiration is more effective? Anaerobic and aerobic
Aerobic as more energy is released from sugars
What is the difference between an organic and inorganic molecule
Inorganic molecules don’t contain carbon (expect CO2) and organic molecules do
What does ambient gas mean
‘Surrounding’ so it’s the gases that surround us
Which atmosphere layer do we live in
The troposphere
What is atmospheric layer is above the troposphere
Stratosphere
What layer is in between the troposphere and then stratosphere
The ozone layer
What was ozone (triatomic oxygen) produced by
Chemical reactions involving oxygen and ultraviolet light in the stratosphere
Why is the ozone crucial for earth
It absorbs harmful UV from the sun, limiting the amount that reaches the earths surface
What % of carbon dioxide is in the atmosphere
0.04%
What reduced carbon dioxide in the atmosphere
It was reduced by autotrophs, because carbon dioxide is a component in photosynthesis
What is carbon sequestration
Where photoautotrophs store carbon dioxide in their biomass to grow
What do biogeochemical cycles show
The flow of chemical elements and compounds between living organisms and the physical environment
Name 5 limitations of early monitoring methods
Lack of ancient historical data / inability to measure many factors / lack of data collected in many areas / limited reliability of proxy data for ancient conditions / lack sophisticated equipment for accurate measurements
Name 5 improved monitoring methods
Collection of long-term data sets / use of electronic monitoring equipment / gas analysis of ice cores / isotope analysis of ice cores / improved carriers for monitoring equipment
What is proxy data
Study of past climates, preserved physical characteristics of the past that stand for weather measurements to enable to reconstruct climate conditions
What is dendrochronology
Tree ring dating, counting tree rings to find out their exact age to help analyse atmospheric conditions
Define climate
Long-term weather trends
