[Re:] types of organization

[Don McAllister]

"Prof. Dov Por" wrote:

> Thomas,
> You are right in your criticism. One-celled  beings are not organisms.   I
> have been used to know that there are three
> levels:cell-tissue-organism.Organisms for instance  have an embryology
> which the unicells do not have. Organisms are complex structures in which
> many different cells participate.

What is a fertilized human egg?  How many cells/tissues does the developing
embryo have to have before it becomes an organism?

don
Don McAllister