soha said:
who created single cell organisms?
Theory
Chemicals of life were formed on Earth.
Urey and Miller set up a closed system set. Powerful electrical sparks were discharged into a glass chamber containing ammonia, hydrogen and methane. After only a week of continual electrical discharges and recycling steam through the apparatus, the condensed water in the flask became red and turbid. When the liquid was analysed through paper chromotography, they found it contained a number of amino acids.
Now, this is the theory that after the big bang, life started on earth. The above experiement represents the early stages of earth, as a gaseous planet, and aims to prove that complex organic molecules (amino acids), can be produced naturally from basic chemical components.
Now, as for your single celled organisms.
The formation of organic molecules came first, then the formation of membranes. Membranes helped protect the system of organic molecules, which evolved into nucleic acids and became capable of self replication.
Procaryotic cells were the first cells. They are also the earliest known type of fossil found.
After procaryotic cells came eucaryotic organisms. They were cells containing a membrane bound nucleus abd cell organelles developed.
Colonial cells - multicellular organisms may have originated when daughter cells became bound together after cell division to develop a colony. Stromatolites are an exame of colonial cells.
And last, but not least. Multicellular organisms, ie us. Multicellular organisms show differentiation Each cell has a specialised function and is dependant on others.
