1.5.U1
Cells can only be formed by division of pre existing cells.

1.5.U2
The first cells must have arisen from non-living material.

Spontaneous Generation

1.5.U3
The origin of eukaryotic cells can be explained by the endosymbiotic theory.

1.5.A1
Evidence from Pasteur's experiments that spontaneous generation of cells and organisms does not now occur on earth