1. Kingdom Plantae
Multicellular Algae
Nonvascular Plants
Vascular Plants

2. Multicellular Algae Characteristic 1 Live in/near water sources

3. Multicellular Algae Characteristic 2 Lack vascular tissue

4. Multicellular Algae Characteristic 3
Some unicellular, some colonial, most multicellular

5. Multicellular Algae Characteristic 4
Reproductive cycles involve alternating sexual and asexual stages

6. Multicellular Algae Characteristic 5 Well-adapted to life in water
Thin leaf-like structures (~2 cells thick)
Movement of materials into the organism is through diffusion
No stems
Ease of sexual reproduction

7. Multicellular Algae Characteristic 6
Adapted to life in the intertidal zone
Cell wall of cellulose and gel-like sugar (slimy and rubbery)
Some have CaCO3

8. Algal groups in phycology
According to:
Chlorophyll and accessory pigments
Form in which food is stored
Multicellular Algae
Division Rhodophyta
Division Phaeophyta
Division Chlorophyta

9. Division Rhodophyta (Red algae)
Habitat
Some freshwater, most marine
Polar regions, tropics
Up to ~260 m depth
Pigments
Chl a (all)
phycoerythrin absorbs blue light
appears green, pink, red, purple, black
Food reserve: Floridean starch
Mostly multicellular; no flagella and centrioles
Chondrus crispus, Irish moss
Lithothamnion glaciale
Porphyra  nori

10. Division Phaeophyta (Brown algae)
Habitat
Mostly marine
Cool, shallow coastal waters of temperate/arctic areas
Pigments
Chl a and c
fucoxanthin
Dusky olive/yellow-brown
Food reserve: laminarin
All multicellular; largest and most complex algae
Macrocystis pyrifera, giant kelp
Padina

11. Phaeophyta structures
Thallus (pl. thalli) “sprout”- plantlike seaweed body
holdfast – attachment
stipe – stemlike support
blade – surface for photosynthesis
bladder – flotation, keeps blades near surface

12. SEXUAL Reproduction in Fucus
Only multicellular part of the life cycle

13. DIvision Chlorophyta (green algae)
Habitat: Freshwater/marine/moist areas
Pigments: Chl a and b, carotenoids
Food reserve: starch
Cell wall of cellulose
Unicellular/colonial/multicellular
Ancestors of modern land plants
Volvox
Ulva

14. Unicellular green alga
Chlamydomonas
Ponds, ditches
2 flagella
Cup-shaped chloroplast
Pyrenoid at base synthesizes and stores starch
2 small contractile vacuoles
Eyespot
Cell wall not made of cellulose

15. colonial green algae Gonium
4-42 identical cells living together but functioning independently
Volvox
500-50,000 cells arranged in hollow spheres
Most cells identical; few produce gametes
Oedogonium
Threadlike colonies
Holdfast cell attached to lake/pond bottom
Asexual reproduction: broken filaments divide and grow
Sexual reproduction: formation of gametes

16. multicellular green algae
Ulva
Intertidal zone of marine habitats
Truly multicellular
2-cells thick but tough

17. Reproduction in chlorophyta
Alternation of generations
Diploid  haploid stages
Asexual  sexual modes of reproduction
Asexual  spore* formation
Sexual  gamete* formation
* Both are haploid reproductive cells
Haploid, N
Diploid, 2N

18. Reproduction in chlamydomonas
(unfavorable conditions)
2N  N
N  N
Dominant stage
Fertilization/Syngamy
Isogamy

19. Reproduction in ulva Multicellular haploid stages with
Multicellular diploid stage with
sporangia that produce spores
N  N
2N  N
Multicellular haploid stages with
gametangia that produce gametes

20. Ecology of Algae “grasses of the sea” home to marine organisms
source of oxygen
source of pharmaceuticals
food products
algin from brown algae
carageenan and agar from red algae
non-food products
Chlorella
Dunaliella
Lithothamnium
Laminaria
Porphyra
Nori
Undaria
Wakame
Kombu