Domain Eukarya KINGDOM PLANTAE Recall the classification so far

Kingdom Plantae 1. Main Characteristics Eukaryotic, mostly multicellular, but also unicellular and colonial Found in aquatic and terrestrial environments. Autotrophic, i.e. photosynthetic, chemosynthesis

Cell wall strengthened with cellulose 1. Main Characteristics (2) Cell wall strengthened with cellulose Alternation of Generation in their life cycle 3 main groups: a) aquatic (algae) b) non-vascular (mosses & liverworts) c) vascular (ferns, trees, flowers, bushes,vegetables, grasses etc.)

2. Reproduction All ‘plants’ undergo alternation of generations, i.e. switch back and forth between the phases of asexual (Sporophyte 2N stage) and sexual (Gametophyte N stage) reproduction

2. Reproduction (2) Sporophyte generation (diploid = 2N); asexual produces spores (N) by the process of meiosis spores germinate and grow into a gametophyte (N)

Gametophyte generation (haploid = N); sexual produces gametes (sex cells) which fertilize, produces a zygote (2N) and grows into a sporophyte (2N) The dominant generation (sporophyte, or gametophyte) varies from plant group Plants first appeared in the water and then adapted to live on land

A. Aquatic Plants (ALGAE) Eukaryotic Mostly multicellular, some are unicellular or colonial

1. NUTRITION Autotrophic (photosynthesis) Possess chlorophyll pigments and other pigments to absorb sunlight energy Some contain pyrenoids that store starch

Fresh/marine water, damp soil, moist tree trunks 2. HABITAT Fresh/marine water, damp soil, moist tree trunks Examples: bull kelp (Nereocystis, ‘trees of the ocean’) Ulva (sea lettuce) Fucus (Rockweed) Spirogyra (stringy filaments in ponds) Chlamydomonas (unicellular) Volvox (colonial) Porphyra (Nori)

Reproduce sexually and asexually Undergo alternation of generations 3. REPRODUCTION Reproduce sexually and asexually Undergo alternation of generations Gametophyte (N) mitosis mitosis Gametes (N) Spores (N) fertilization meiosis Zygote (2N) Sporophyte (2N) mitosis

PHYLUM CHLOROPHYTA (green algae) 4. CLASSIFICATION Grouped according to the type of chlorophyll, the type of accessory pigments, their form of food storage, and their cell wall composition. There are 3 groups: PHYLUM CHLOROPHYTA (green algae) E.g. Chlamydomonas, Spirogyra, Ulva (sea lettuce), Volvox, Eelgrass etc. (‘seaweeds’)

PHYLUM PHAEOPHYTA (brown algae) E.g. Nereocystis (bull kelp), Fucus (rockweed), ‘laminarians’

Kelp forests

PHYLUM RHODOPHYTA (red algae) E.g. Coralline red algae, Porphyra

ECOLOGICAL USES OF ALGAE 1. The groups of algae (brown, red, green) provide 50 – 75% of the earth’s oxygen 2. Form the basis of many food chains e.g. green algae  zooplankton  shrimp  fish  seals (etc)

ECOLOGICAL USES OF ALGAE 3. Multicellular algae (e.g. kelps, Ulva, eelgrass beds) provide shelter, habitats and food for many animals such as sea stars, sea urchins, crabs, anemones, sponges, fishes, Great Blue Heron, Kingfishers, otters etc.

Eelgrass bed at low tide Dallas Road, Victoria Eelgrass bed at low tide

ECOLOGICAL USES OF ALGAE 4. Multicellular algae (e.g. kelps, Ulva, eelgrass beds) also provides nurseries and stabilizes the substrate. Black Rockfish in a kelp forest

ECOLOGICAL USES OF ALGAE 5. Red algae (e.g. coralline) help to form coral reefs and beds. Black Rockfish in a kelp forest

$ ECONOMICAL USES OF ALGAE $ Used as thickening/binding agent for food and non-food items e.g. carageenan – primarily dairy products (ice cream, pudding, custard, salad dressing etc) algin – used as a binder in plastics, paint, drugs, waxes, deodorant, make-up, toothpaste etc.

2. Commercially grown and harvested (brown & red) for food, e. g 2. Commercially grown and harvested (brown & red) for food, e.g. Nori, soup flavouring, sauces 3. Algae products in poultry feed, pie fillings, doughnuts, cake mixes

4. Used in medicine to produce antibiotics, source of vitamin C, source of agar used to grow bacteria and other microorganisms A summary of the many economic uses of Algae

Homework on Uses of Algae Go to your next empty full page and title it, “Examples of Algin/Alginate and/or Carageenan in Food or Industrial Products”. Glue or staple the product label and ingredients from 5 examples you have in your house that contains the algae. Highlight the type of algae found in your household item.

ALGAL/ALGAE ADAPTATIONS IN WATER Some multicellular algae have developed holdfasts to adhere to rocks and floats/bladder filled with gas that keep them upright for photosynthesis e.g. Bull kelp ….please sketch the following structures of a typical ‘bull kelp’.

Structures of a Bull Kelp

ALGAL/ALGAE ADAPTATIONS IN WATER (cont’d) 2. Sexual reproduction is easily accomplished because the gametes are motile and they move through water by flagella.

ALGAL/ALGAE ADAPTATIONS IN WATER (cont’d) 3. Accessory pigments absorb different wavelengths of light for photosynthesis. 4. Gas exchange of O2 and CO2 and nutrients directly from H2O by diffusion.