A2.1-Origin of cells Flashcards
how many covalent bonds does carbon form? and what does it allow it to don ?
it forms 4 covalent binds which allows it to form large complex molecules
when and how was the earth formed?
it was formed 4.6 billion years ago when gravitation pull and the heat from radioactive decay formed a hot, molten proton earth
how did water come to earth?
asteroids that hit earth brought water as they are frozen water so when the earths surface cooled water was left on the surface.
what is a reducing atmosphere?
an oxygen poor atmosphere where things tend to gain electrons , reduction.
what was the first atmosphere like?
it was mainly composed of hydrogen and helium but these gases eventually dissipated into space.
what was the second atmosphere like ?
it was composed of water vapour carbon dioxide and methane, these are all green house grass so as a result the earth was very very hot. ammonia hydrogen sulphide and hydrogen were also there but importantly no oxygen was present.
why was life presented from developing on early earth?
because there was no ozone layer so lots of uv radiation was being emitted to earth, it is toxic so life couldn’t develop.
