On Earth, everything is made up of cells, and cells come in two basic types, Prokaryotic and Eukaryotic. ‘Pro’ means before, and ‘eu’ means ‘true’ or ‘good’. So "Prokaryotic" means "before a nucleus," and "eukaryotic" means "possessing a true nucleus." This is one of the differences between the two cells with Prokaryotic having no nuclei and eukaryotic having a true nuclei. However this is only of a few differences between the two.
They do also have a lot in common; they perform the same kinds of functions in the same way, both are enclosed plasma membranes and both contain DNA. Some of the differences are; eukaryotic cells are larger and more complex, (prokaryotic cells are about 1000 times smaller than eukaryotic cells) and their DNA is linear compared to prokaryotic which is circular.
On studying the two types of cells it is clear that there is a connection between the two. Scientists have no doubt that the eukaryotic cell is clearly developed from the prokaryotic cell. Within eukaryotic cells you find the organelle called a mitochondrion, and within the prokaryotic cells you find an organelle called plastids, the most famous being chloroplast. Both organelles have a similar evolutionary origin. Both are clearly descendents of prokaryotic cells which have taken up residence within other cells, which is known as endosymobiosis. Secondary endosymbiosis occurs when the product of primary endosymbiosis is itself engulfed and retained by another free living eukaryote. Secondary endosymbiosis has occurred several times and has given rise to extremely diverse groups of algae and other eukaryotes.
Cyanobacteria are prokaryotic often referred to as ‘blue - green algae’. While most algae are eukaryotic, cyanobacteria are the only exception. They use photosynthesis to gain energy. Cyanobacteria are very old, with fossils dating back to four million years ago. While prokaryotic cyanobacteria themselves reproduce asexually through cell division, they were instrumental...