Phylum: Chlorophyta

Link to Chlorophyta image directory

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Of all the phyla in the kingdom Protista, this is the one which is most directly relevant to botanists. This is because plants are believed to have evolved from the green algae. There are several lines of evidence that lead us to this conclusion:

1. Green algae have the same photosynthetic pigments as plants (Chlorophylls a & b)

2. They store their food as starch in plastids (chloroplasts) - unlike plants (except hornworts!) starch deposition is associated with a structure called a pyrenoid.

3. Some have cell walls composed of cellulose.

4. One class of the Chlorophyta, the Charaphycean green algae, undergoes cytokinesis, like plants, through the creation of a cell plate mediated by a phragmoplast.

You need to know the following nine examples

Volvocine Line: Chlamydomonas, Pandarina and Volvox all have similar cells, and represent a phylogenetic clade.

Chlamydomonas

Pandorina

Volvox

Charophyceaen Green Algae- Cell division associated with a phragmoplast.

Desmid, Cosmarium

Spirogyra

Chara


Ulva belongs to different lineage of grren algae that we are not teaching.

Ulva