DIVERSITY OF LIFE
SYNOPTIC DESCRIPTION OF THE PHYLUM PRASINOPHYTA
|The following description came from van den Hoek et al. (1995), Melkonian (1989, 1990), Melkonian and Surek (1995), and Sym and Pienaar (1993).|
|I. SYNONYMS: praesinophytes,|
|II. NUMBER: >180 species.|
III. PHYLUM CHARACTERISTICS:
A. Structure and Physiology
Cell Form: Generally, unicells; some (Prasinocladus) are benthic filaments.
Basal Bodies: Basal bodies with roots that are cross-shaped to unilateral; those with the broad roots have a multilayered structure (MLS) some with rhizoplast and broad flagellar roots, others with flagellar roots associated with the cell surface.
Cell Covering: Usually covered with elaborate scales of cellulose. Some naked.
Food Reserves: True starch that is deposited within the chloroplast in association with a pyrenoid.
Nucleus: Presumed haploid in vegetative forms.
Centrioles: Not present
Inclusions and Ejectile Organelles: Not present.
B. Mitosis, Meiosis and Life History
Meiosis: Present at least in Nephroselmis.
Sexual Reproduction and Life History: Confirmed in only one genus, Nephroselmis, which is isogamous and haplontic.
C. Ecology: Found in marine, brackish, and fresh water. Free-living and flagellated, or benthic with quadriflagellate zoospores.
By Jack R. Holt. Last revised: 03/19/2013