1. BIO 4320 – marine algers systematikk og biologi
Division ”CHLOROPHYTA”

2. Origin of chloroplast
Chlorophyta

3. Phylogeny of Chlorophyta sensu lato

4. Chlorophyta sensu lato
5-10 classes
Freshwater and marine;
ca species

5. Division characteristics
morphology
Flagellates, colonies
Filaments
Parenchymatic
Ulva
Dunaliella

6. Division characteristics
Isokont swarmers
”smooth” flagella or covered by scales
Stellate transition zone (flagella apparatues)
Dobble chloroplast membrane
Chloroplasts with 2-6 thylakoids, grana
Green chloroplast with:
chlorophyll a og b
β-karoten and xanthophyls
Some have pyrenoid (in chloroplast)
Storage product: starch (in chloroplast)

7. Bloom on the Southern coast of Norway

9. Chloroplast pigments chlorophyll a + b carotenoids β-karoten
Xanthophylls
lutein
violaxanthin
neoxanthin

10. flagella ”smooth” in Chlorophyceae
with organic scales in Prasinophyceae
flagella

11. Flagellar transition zone
from van den Hoek et al. 1995

12. sheding of flagella
from van den Hoek et al. 1995

13. flagellar roots of UTC
UTC clade
UTC clade = Ulvophyceae-Trebouxiophyceae Chlorophyceae
Chlorodendrales moved from Prasinophyceae to Chlorophyta
Prasinophyceae may be split into several classes

14. Microtubular roots of UTC
Microtubular roots run beneath the cell membrane to the posterior part of the cell
anchor the flagella to the cell
constitute a tubular cytoskeleton
4 flagellar roots:
2 consist of 2 microtubuli
2 consist of 4 (usually) microtubuli

15. Microtubular roots of UTC
Microtubular roots run in oppsite directions forming a cross-like pattern in apical view
3 principal arrangements can be distinguished based on displacement of basal bodies
Characterized as cruciate (three types)
clockwise
opposite
counterclockwise

16. Flagellar apparatues Ulvophyceae CW Trebouxiophyceae CCW DO
Cruciate
UTC-clade (a-c)
Ulvophyceae CW
Trebouxiophyceae
CCW
Prasinophyceae DO
Chlorophyceae
MLS
Charophyceae
Prasinophyceae
multilayered structure

17. Chlorophyceae cruciate and clock wise flagellar bases
from van den Hoek et al. 1995

18. Chlamydomonas reinhardtii flagellar bases and roots
Clockwise:
1 o’clock – 7 o’clock type
(connective fibres omitted)
from van den Hoek et al. 1995

19. Chlamydomonas reinhardtii flagellar bases and roots
upper striated connective
connective fibres with centrin
lower striated connective
from van den Hoek et al. 1995

20. Chlamydomonas reinhardtii rhizoplast
Contraction/relaxation
contracted
relaxed
connective fibres
rhizoplast
nucleus
from van den Hoek et al. 1995

21. Mitosis
open; nuclear membrane disperse during metaphase (Charophyceae)
closed; nuclear membrane is persistent (many UTC)
Trebouxiophyceae; closed mitosis with metacentric spindle
(see fig 16.8)

22. clade U T C
Present in brackish water

23. Cell wall Cells are naked with cell wall
or covered with organic scales

24. Cell division Cytokinesis by furrowing (Prasino-,Trebouxiophyceae)
by phycoplast-furrowing (chlorophyceae)
Mode of division of systematical importance

25. Mitosis and cell division
8 different modes have been distinguished

26. occurrence freshwater, brackish water, salt water
rock pools, ponds and snow
humid soil, tree trunks, stones
Tropical, temperate and polar milieu

27. diversity Cell size from < 1 μm to 20-30 cm
Flagellates, coccoids, colony forming, filamentous and parenchymatic