TOPIC 1 CONDITIONS FOR LIFE Flashcards
(22 cards)
Features of earth that made it suitable for life ?
mass
distance from sun
axis of rotation
speed of rotation
magnetic field
How does the speed of the earths rotation make it suitable for life?
Due to the 24 hour cycle - prevents earth being warmed too much or equally being cooled too much
How does the mass of the earths rotation make it suitable for life?
mass is great enough to prevent gases from escaping eg. carbon, hydrogen etc
How did liquid water allow life to develop on earth?
. Involved in chemical reactions
. Acts as a solvent to transport substances around organisms
. Created aquatic habitats
. Evaporation to regulate body temperature
How did Nitrogen allow early life to develop?
Creation of proteins
What gas was not present during early life?
Oxygen
How did Carbon Dioxide allow early life to develop?
Photosynthesis
Word equation for photosynthesis
Carbon Dioxide + Water -> Glucose + Oxygen
How did the temperature range allow life to develop on earth?
warm enough for liquid water but cool enough that enzymes do not denature. 0-35 degrees celcius
Why was solar insolation so important during the development of life on earth?
sunlight provided energy for photosynthesis
How did carbon sequestration cause environmental change?
Prevented long term temperature rise due to reduction in carbon levels
How did transpiration cause environmental change?
Returned water vapour to atmosphere which increased rainfall, enhancing plant growth
What is transpiration?
Transpiration is the process by which plants absorb water through their roots, move it through their stems, and release water vapor through small openings in their leaves called stomata.
How did biogeochemical cycles cause environmental change?
Biogeochemical cycles developed which meant small amounts of nutrient elements could support life over long periods of time without being depleted
How did atmospheric oxygen cause environmental change?
. Archaea developed the ability to photosynthesise 2.7 billion years ago
. Oxygen kept reacting with iron in the ocean causing iron deposits
. Once all the iron had reacted the oxygen went into the atmosphere
. Once in the atmosphere it reacted with UV light to cause the dynamic equilibrium of the constant formation and destruction of ozone we see today
What is proxy data?
preserved physical characteristics of the environment that can stand in for direct measurements
what are three common types of proxy data?
. dendrochronology
. pollen from peat bogs
. hand written/drawn accounts by people from history
How does dendrochronology work ?
. every year trees grow two rings
Wider one in spring
Thinner/darker one in summer
What does a wide ring mean in denrochronology?
Warmer/wetter
What does a thin ring mean in dendrochronology?
Cooler/drier
How does proxy data using pollen from peat bogs work
. plants from past produce pollen
. pollen gets trapped in peat and peat builds up
. using quantity of pollen we can infer climate
