1. Multicellular Primary Producers: Seaweeds and Plants
Chapter 6
Honors Marine Biology

2. Multicellular Primary Producers
As inhabitants of land, our perception of photosynthesis is mostly based on
Many photosynthetic organisms are not considered plants (i.e., they are not classified under Kingdom Plantae)
Photosynthetic bacteria
Unicellular algae

3. Multicellular Algae: The Seaweeds
Formally called ____________________ or ___________________
By definition, seaweeds are all MULTICELLULAR
Classification of seaweeds is based on their:

4. The Seaweeds
Wide range of variation seen in multicellular algae:

5. The Seaweeds General structure: Several unifying features:
All lack true leaves, stems and roots
Thallus(s.) – Thalli (pl.):
Blades:
Pneumatocysts:

6. The Seaweeds
General structure (cont’d):
Stipe:
Hold-fast:

7. Types of Seaweeds 1. Green Algae:
Only 10% of an estimated 17,000 species are thought to:
Pigments and food reserves of green algae are the same as terristrial plants so it is thought that:

8. Types of Seaweeds Brown Algae:
Have high concentrations of yellow pigments
Many species have rockweeds or wracks:

9. Types of Seaweeds Kelp: Most complex and largest of all brown algae
Most are found below the tide level in:

10. Types of Seaweeds Kelp forests (kelp beds): Found in the Pacific ocean
Harvested for several economically-important, natural products

11. Types of Seaweeds Red Algae:
Very numerous species; most of which live in
Inhabit most shallow-water marine environments
Some are harvested for:

12. Types of Seaweed Red Algae (cont’d): All have phycobilins:
Coralline algae:

13. Life Histories of Seaweeds
Reproduction is very complex in the seaweeds and includes:
Sexual reproduction
Spore production
Alternation of generations
Isomorphic versus polymorphic gametophyte

14. Economic Importance of Seaweed
Seaweeds have always been utilized by humans
Aquaculture:
Phycocolloids:
Algin:

15. Marine Flowering Plants
Dominant plants on land but are also found in oceans
They have true leaves, stems, and roots and belong to Kingdom __________________
Referring to seagrasses, salt-marsh plants, and mangroves

16. Marine Flowering Plants
1. Seagrasses:
Live completely submerged
Time their pollen release to occur with the:
Seeds have bristles

17. Marine Flowering Plants
2. Salt-Marsh Plants:
Do not tolerate total submergence by seawater
Provide a valuable ecosystem service:
Organic matter is available to them mostly as detritus

18. Marine Flowering Plants
3. Mangroves:
Thick leaves to reduce: