The Origin of cells
There are two theories involved in the orgin of cells:
1. Cells can only be formed by the division of pre-existing cells
1. Cells can only be formed by the division of pre-existing cells
This theory, proposed by Rudolf Vrichow, suggests that all cells come from other cells through the process of mitosis, in which the cell is divided in to two identical cell daughters
2. Spontanepus Generation Theory
This theory suggests that the first cells must have arisen form non-living materials.
Recipe for the origin of life:
1)The synthesis of simple organic molecules (amino acids) from inorganic molecules (water, carbon dioxide, ammonia)
2)The assembly of these molecules into polymers (e.g. polypeptides from amino acids)
3)Formation of polymers that can self-replicate to allow for inheritance of characteristics
4)Development of membranes with internal chemistry different from their surroundings
This theory suggests that the first cells must have arisen form non-living materials.
Recipe for the origin of life:
1)The synthesis of simple organic molecules (amino acids) from inorganic molecules (water, carbon dioxide, ammonia)
2)The assembly of these molecules into polymers (e.g. polypeptides from amino acids)
3)Formation of polymers that can self-replicate to allow for inheritance of characteristics
4)Development of membranes with internal chemistry different from their surroundings
THE EDOSYMBIOTIC THEORY
This theory proposes that Eukaryotic cells come from chloroplasts and mitochondria that were once free living prokaryotes due to their particular possesion of their own DNA, double membrane and 70S ribosomes. It states that these were swallowed by larger prokaryotes and thus converted into organelles in the Eukaryotes