[Geysers] Three items

[Greg Wimpey]

On Fri, 2005-01-28 at 18:33, TSBryan at aol.com wrote:

>  
> Item #3. I know blue-green algae (old name) and cyanobacteria (new
> name) are for the same "critter". But I also understood that the
> change from alga to bacteria had to do with cell nuclei (or lack
> thereof), so that the names WOULD NOT be interchangable. There's my
> real query.
>  

A quick browse of Google results seems to show that "algae" is a rather
ill-defined term.  You are right in that cyanobacteria, like all
bacteria, do not have a cell nucleus.  Other forms of algae are
eukaryotes (they have a nucleus).  So, algae would be what biologists
call a polyphyletic category: it contains organisms from different
evolutionary lineages.  I think it's probably a term of convenience for
"any very simple plant-like organism".