General understanding for first year botany students

1. GENERAL CHARACTERS OF
DIVISION CHLOROPHYTA

2. DISTRIBUTION
• Wide range of distribution
– Aquatic
• Fresh water
• Marine water
– Terrestrial

3. DISTRIBUTION
• Still / Stagnant water
– Volvox
– Spirogyra
– Chlamydomonas
• Fresh flowing water
– Oedogonium
– Cladophora

4. DISTRIBUTION
• Marine Water Species
– Caulerpa
– Bryopsis
• Terrestrial Species
– Trentepholia
– Pleurococcus

5. CELL STRUCTURE
• Eukaryotic
• Extremely Variable Shapes
• Cell wall composed of two layers
• Inner layer made up of Cellulose
• Outer layer made up of Pectic substances
• Protoplast surrounded by cell membrane
• Protoplast vacuolated
• Cell may be Uni-nucleated or Multi-nucleated

6. Chloroplast in Chlorophyta
• The most prominent feature of the cell
• Variety of shapes
• Number of Chloroplasts is also variable

7. Shapes of Chloplast
• Cup shaped – Chlamydomonas
• Stellate – Zygnema
• Ribbon shaped – Spirogyra
• Discoid – Cladophora
• Reticulate – Oedogonium

8. Cup shaped – Chlamydomonas

9. Stellate– Zygnema

10. Ribbon shaped – Spirogyra

11. Discoid – Cladophora

12. Reticulate – Oedogonium

13. The Pigments
• Chlorophyll a
• Chlorophyll b
• Carotenes
• Lutein
• Lycopene
• Zeaxanthin
• Violaxantin
• Neoxanthin
• Siphoxanthin

14. Reserve Food
• Chloroplasts are associated with Pyrenoids
• Pyrenoids – Bodies for reserve food material
• Central core – Proteinacious
• Surrounded by starch plates

15. Range of thallus
• Unicellular and Motile
• Unicellular and Motile but colonial
• Unicellular non motile coccoid
• Filamentous unbranched
• Filamentous branched
• Parenchymatous thalloid
• Heterotrichous form
• Siphonaceous form

16. Unicellular and Motile
• Chlamydomonas

17. Unicellular and Motile but colonial
• Volvox

18. Unicellular non motile coccoid
• Scenedesmus • Chlorella

19. Filamentous unbranched
• Ulothrix • Zygnema

20. Filamentous branched
• Cladophora

21. Parenchymatous thalloid
• Ulva

22. Heterotrichous form
• Chaetophora

23. Siphonaceous form
• Caulerpa

24. Economic Importance of Algae
• Agriculture
• Chemical Industry
• Medicine
• Food

25. Economic Importance of Algae
• Algae As Food
– Rich source of Proteins, Fats and Vitamins
– Algae like Laminaria, Gracilaria used as food in
China
– Porphyra used as supplimentary diet by Japnese

26. Economic Importance of Algae
• Algae As Food
– Phaeophyceae(Brown Algae)
• Laminaria& Sargassum
– Rhodophyceae(Red Algae)
• Porphyra & Palmaria
– Chlorophyceae(Green Algae)
• Ulva, Chlorella, Spirulina & Caulerpa

27. Algae As Food
– Phaeophyceae(Brown Algae)
• Laminaria& Sargassum

28. Algae As Food
– Rhodophyceae(Red Algae)
• Porphyra & Palmaria

29. Algae As Food
– Chlorophyceae(Green Algae)
• Ulva, Chlorella, Spirulina & Caulerpa

30. Economic Importance of Algae
• Algae As Food – Some Important Products
– Agar-agar – Gelidium, Gracilaria & Hypnea
– Glycerol
– Sorbitol
– Dulcitol
– Floridian Starch
– Spirulina – Protein Rich nutritional Supplement

32. Economic Importance of Algae
• Algae As Biofertilizers
– Algae which fix Atmospheric Nitrogen
• Anabaena
• Nostoc
• Tolypothrix
– Algae form symbiotic relation with other plants
• Anabaena and Azolla (Pteridophyte)(an aquatic plant)
– used in Rice fields

33. Anabaena
Nostoc
Tolypothrix
Tolypothrix

34. Economic Importance of Algae
• Algae As Biofertilizers
– Used directly as Fertilizers as they are rich in
Potassium but poor in Nitrogen
– Some times sea weeds are burnt and ashes are
spread in the fields

35. REPRODUCTION IN ALGAE
• Vegetative reproduction
• Asexual Reproduction
• Sexual Reproduction

36. REPRODUCTION IN ALGAE
Alternation of Generation
Alga
(n)
Male Gametangia
(n)
Gamets
(n)
Zygote
(2n)
Zygospore
(2n)
Female Gametangia
(n)
(n)(n) (n) (n)
Gamets
(n)
Mature Spores
(n) Sexual
Reproduction
Asexual
Reproduction
Spores
(n)
Germination of Spores
(n)