Euglenophyta

PLANT GROUPS
(6)
Euglenophyta
General characteristic of the Euglenophyta
Habitat Fresh water, Brackish water, a few marine water
Pigments Chlorophyll (a & d), ?-carotene
Food reserve Paramylum (? 1, 3 glucose polymer)
Cell wall No cell wall but have Pellicle
Growth form Unicellular flagellate
Flagella Two but only one emerging from the gullet
Reproduction Sexual not found, Asexual by longitudinal binary fission

Division Euglenophyta
Class Euglenophyacae
Order Euglenales
Family Euglenaceae
Genus Euglena

The longer flagellum extends forward, and is covered by two distinct kinds of fine hairs. Eyespot is in cytoplasm near the gullet, not in plastid. A contractile vacuole is present at the apical end of the cell, empties into reservoir. Pellicle lies within the cytoplasm, at the surface of the cell, Composed of spiral strips of protein that overlap slightly. In many species, these can slide with respect to each other, this produces a distinctive mobility called euglenoid movement, or metaboly. Euglena grown at high temperature will lose its plastids, in studies of the herbicide diquat, Euglena was found to grow slightly faster in presence of high concentrations of the herbicide, Chloroplasts were completely inactive, but Euglena was growing heterotrophically, using diquat as food.












Bacillariophyta (Diatoms)
General characteristic of the Bacillariophyta
Habitat Aquatic & Terrestrial
Pigments Chlorophyll (a & c)
Food reserve Fat & Chrysolaminarin
Cell wall Hemicellulose & Silica
Growth form Unicellular & Colonial
Reproduction Asexual, Sexual (Isogamy, Oogamy)

The cell wall of diatoms consists of two parts which overlap like halves of a petridish.

Classification of Diatoms
On the basis of symmetry & secondary structure on the valve surface, diatoms divided into two orders:

1) Centrales: Radial symmetry, Oogamous
2) Pennales: Bilateral symmetry, Isogamous
The siliceous walls resist dissolution & decay after the death of organism & accumulate as fassils.