Rhodophyta
The phylum of the red algaes.

Radiolarian-ooze
Sediments found in the deeper ocean (below 3,600 meters), and
composed of the silica
shells of radio-larians.

Red tide
A condition caused by an extermely dense population of
planktonic organisms. Most commonly caused
by Dinoflagellata.

Radula
A hard band with minute teeth used by most mollusks to
scrape food off rocks. Not found in bivalvia.

Respiratory tree
The major respiratory organ of the sea cucumbers.

Ribosomes
The site of celluasr protein synthesis.

RNA(Ribonucleic acid)
Works in conjunction with DNA to carry out heredity orders
to the body.