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

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

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

The Seaweeds Wide range of variation seen in multicellular algae:

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

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

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:

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

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

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

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

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

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

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

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

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

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

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