1. Aquatic Plants – Green, Red, and Brown Algae

2. Green Algae 6000 species single cells colonies long filaments.
Chlamydomonas
Spirogyra
Ulva

3. Green Algae aquatic (freshwater or marine) or terrestrial
form symbiotic relationships with fungi to form lichens.
Caulerpa – an invasive seaweed
Algal bloom
Volvox

4. Characteristics of Green Algae
chlorophyll a & b (green color)
Some have flagella for movement
cell walls with cellulose

5. Characteristics of Green Algae
Sexual reproduction: go through 2 different life stages using a method called “alternation of generations
Asexual reproduction: by fission, fragmentation or zoospores (motile spores)

6. Alternation of Generations
A life cycle in which there are two distinct life stages that occur alternately for a species
Stage 1
Diploid (2N – each cell has two sets of chromosomes)
Called the sporophyte
Produce gametes (= sex cells = haploid cells) by meiosis
Stage 2
Haploid (1N – each cell has one set of chromosomes)
Called the gametophyte
Fuse to form a sporophyte (= zygote = diploid cells) by fertilization

8. Chlamydomonas Characteristics Unicellular Motile, 2 equal flagella
Occur in stagnant water and damp soil, fresh water and salt water, even in snow!
Have a nucleus inside their chloroplast
Possess two small vacuoles which function to remove waste
Have a light sensitive, red pigment spot which allows the cells to swim towards light

9. Chlamydomonas Life Cycle
Take a good look at the diagram below of the life cycle of Chamydomonas which is an example of alternation of generations Note the diploid (2N) and the haploid (1N) stages of its life.
Diploid (2N)

10. Spirogyra
Algal cells are joined end to end to form filaments (multicellular)
Mostly freshwater
Generally free floating
Reproduces asexually by fragmentation and sexually by conjugation
Does not form gametes,
therefore does not go
through alternation of
generations
Undergo conjugation –
exchange of genetic information

11. Ulva (sea lettuce) Multicellular green algae (looks like a plant)
Lives in marine and brackish water
Has flat, blade like leaves called a thallus which is made up of two layers of cells
Gametes are free-swimming and a zygote is formed in the water

12. Ulva Life Cycle Mitosis: 1 cell becoming 2 equal diploid cells
Meiosis: 1 cell becoming 4 haploid cells (gametes)

13. Lichens
Can be formed by a symbiotic relationship between green algae and a fungus
The fungus provides the algae with water and minerals that it absorbs from whatever it is growing on and protects the algae by retaining water and serving as a larger capture area for minerals and nutrients

14. The algal cells uses minerals and water to make food for the fungus and itself
Stained slide

15. Youtube
killer algae #1
killer algae #2
killer algae #3
killer algae #4
killer algae #5
volvox
chlamydomonas
algae lady on Vancouver Island
elodea cytoplasmic streaming– an aquatic angiosperm not an algae
algae as a biofuel
algae as biofuel
algal blooms are centre stage

16. Red Algae - Rhodophyta
Red algae are red because of the presence of the pigment phycoerythrin; this pigment reflects red light and absorbs blue light. Because blue light penetrates water to a greater depth than light of longer wavelengths, these pigments allow red algae to photosynthesize and live at somewhat greater depths than most other "algae".

17. Importance of red algae
Nori sushi
high vitamin and protein content
relative simplicity of cultivation, which began in Japan more than 300 years ago.
Agar
Bacterial growth medium
Carrageenan
-food additive/thickener

18. Importance of red algae
important in the formation of tropical reefs,
in some Pacific atolls, red algae have contributed far more to reef structure than other organisms, even more than corals.
called coralline algae, because they secrete a hard shell of carbonate around themselves, in much the same way that corals do.

19. Nori – red algae used for food/sushi

20. Agar agar – red algae used for food and bacterial cultures

21. Carrageenan – red algae used as a food additive and thickener

22. Coralline algae

23. Brown algae - phaeophyta
May reach over 30 meters in length.
Almost all are marine.
Pigments
chlorophyll c and fucoxanthin.

24. Brown algae - phaeophyta
Blades (analogous to leaves)
branch from the stipe, or stalk
Receptacles
form on the surface of the blades
structures in which the gametes are produced.

25. Sargassum – brown algae
Pelagic
(free-floating)

26. Fucus – also called rockweed
Attached to rocks via stipes

27. Youtube
kelp forest
cousteau kelp forest

28. 5 Really Bad Algae Jokes…..
Why did the algae and the fungus get married?
They took a lichen to each other.
Why do many algae couples drift apart?
They prefer planktonic relationships.
Why couldn't the algae keep a girlfriend?
He wasn't a fungi.
Why did the algae get pulled over on his way to the pond?
He was chloro-plastered.
Why did the algae fail math?
He divided when multiplying.
He didn’t know algae-bra.