Chlorophyceae

  • Cell division is by a phycoplast of microtubules that form parallel to the plane of division
  • The spindle disintegrates after anaphase separation or In some species the there is a furrowing of the cytoplasm membrane oriented by the phycoplast while in still other species vesicles coalesce to form a cell plate that divides the cell.
  • If motile cells exist, then the flagella are inserted anteriorly and from the basal bodies, 4 bundles of microtubules cross out in a 'cross-my-heart' or x configuration
  • Life cylcle is zygotic meiosis

The Chlorophyceae includesa number of major groups distinguished primarily by basic differences in the arrangement of their flagellae; the 2 which we will review include the

a. The filamentous greens ( Ken and Nick)

 b. The volvocine line (Debbie & Lisa)

as well as the:

Order Chlorococcales which includes Hydrodictyon ( a nonmotile colonial ) and Pediastrium

 

* Chlorellales - Members of this order have opposed flagellae (12 o'clock-6 o'clock), though some have only vestigial flagellae and so have not been definitively associated with this group. Similarities with members of the Chlorococcales make distinctions difficult.


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