About the geologic time scale divisions
The geologic history of the Earth is broken up into hierarchical chunks of time. From largest to smallest, this hierarchy includes eons, eras, periods, epochs, and ages.
some of the special structures in the members of these phylum as follows:
Members of porifera are sponges. they have collar cells and cellular -level body organization. Cnidarian have stinging cells present on the tentacles around the mouth. Ctenophorans have comb-like plate cells for swimming. Platyhelminthes - members are first to have sensory and nervous tissue in the head region.
A eukaryotic cell can replicate itself two ways. Hope this helps!
