Why is cyanobacteria bacteria not algae?

Answer 1

At one time cyanobacteria were called blue-green algae and were included with the algae. However, like bacteria and unlike algae, cyanobacteria are prokaryotes, meaning that they do not have a nucleus. For this reason they were removed from the algae (which are eukaryotes) and put into the bacteria, with all the other prokaryotes. See: http://www.ucmp.berkeley.edu/bacteria/cyanomm.html http://fig.cox.miami.edu/Faculty/Dana/cyano.html

Answer 2

This is because bacteria as a whole are prokaryotic - no nucleus, very different structures for cell membranes and ribosomes, and the list continues. Although aggregations of cyanobacteria function similarly to algae, their cellular and molecular features are very different. This is why taxonomists put them into two separate kingdoms.

The differences between cyanobacteria and algae can be compared to the differences between a koala and a sloth. Both are slow moving, aboreal herbivores; however, a koala is a marsupial and a sloth is a placental mammal. There are major differences between the two animals, even though they superficially act about the same.

Answer 3

All plants are eukaryotic and bacteria including cyanobacteria are prokaryotic