Page 35 - Algae
P. 35

18                                    Algae: Anatomy, Biochemistry, and Biotechnology





































                  FIGURE 1.25 Trichome of Arthrospira sp.  FIGURE 1.26 Cells of Prochloron sp.
                  (Bar: 20 mm.)                         (Bar: 10 mm.)


                  nanoplankton and obligate symbionts within marine didemnid ascidians and holothurians, and are
                  mainly limited to living in tropical and subtropical marine environments, with optimal growth
                  temperature at about 248C. Prochlorophytes possess chlorophylls a and b similar to euglenoids
                  and land plants, but lack phycobilins, and this is the most significance difference between these and cya-
                  nobacteria; other pigments are b-carotene and several xanthophylls (zeaxanthin is the principal
                  one). Their thylakoids, which lie free in the cytoplasm, are arranged in stacks. Prochlorophytes

























                  FIGURE 1.27 Heterocyst (arrow) of Anabaena azollae. (Bar: 10 mm.)
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