conditions for life on earth

Question 1

How does mass affect life on earth

Answer 1

The large mass of the earth plays a key role as it provides a large enough force to keep the gases in our atmosphere from escaping into space; e.g. hydrogen, carbon dioxide, oxygen and carbon.. The mass also allows for perfect atmospheric pressure conditions.

If the pressure was higher, liquid water would boil and there would be no oceans.

Question 2

Distance from the sun

Answer 2

As the distance from the sun and a planet increases, the mean surface temperature decreases. There is a goldilocks zone, where earth is, where the temperature is almost perfect for life.

Question 3

Rotation of the earth (including the earth on an axis)

Answer 3

The speed of the earths rotation is 24 hours, which is fast enough to minimise excessive heating and cooling. The Axis also allows for there to be various seasons

Question 4

Magnetic field

Answer 4

Beneath the crust of the earth in the outer core, there are molten layers of metal which produce a convection current which produces a magnetic field. This deflects “solar winds” from the sun, which prevents damaging radiation from reaching the Earths surface

Question 5

Atmospheric oxygen

Answer 5

2.7 bill years ago, archaea developed the ability to photosynthesise, so CO2 went down and O2 up

The bacteria at one point died out and the process was taken over by algae and then plants. O2 built up until 540 mill y ago. It was stored as Iron oxide in the ocean, but when it ran out, it went into the atmosphere.

Question 6

Ozone layer

Answer 6

Due to oxygen, an ozone layer formed, (dynamic equilibrium formed from O and O2 as UV energy is converted into chemical energy)-(ozone is O3) which was crucial for animals to go from sea to land. The layer of ozone filtered out highly damaging UV radiation that would have damaged the DNA of any organism that absorbed it

Question 7

carbon sequestration

Answer 7

CO2 keeps heat energy in the atmosphere. Photoautotrophs absorbed this CO2 which prevented long term temp rises.

Question 8

biogeochemical cycles

Answer 8

Over time, greater varieties of organisms evolved, causing interconnecting biological process, causing biogeochemical processes. This allowed for small amounts of elements to support life over a long period of time, preventing build up of waste products/shortages of resources.