Multicellular Protists

Multicellular Protists

• Seaweed
• Large multicellular algae with complex structure
• Cell walls filled with algin: gel-like substance Examples:
• Thickening agent,
• waterproof and fireproof fabric

Archaeplastids

• Viewed as "ancient chloroplasts"
• Likely the endosymbiont that absorbed a photosynthetic Cyanobacteria, enabling it to use photosynthesis

Red Algae

• Pigment turns it red, masking the green chlorophyll
• Contains the multicellular seaweeds

Green Algae

• Chlorophytes
• Chlorophyll produces green pigment
• Most inhabit fresh water
• Contains both unicellular and multicellular species
• multicellularity allows for division of labor
• Charophytes
• Complex, multicellular organisms
• Closely related to land plants (sister taxa)
• Freshwater algal blooms
• Eutrophication: too many nutrients
• Caused by chemical and animal runoff
• Occurs in warm water
• When algal bloom dies it creates a mat
• aerobic bacteria decompose the dead algae and consume all the oxygen in the water
• kills other aquatic organisms

Other Groups

• Other multicellular protists
• Rhizaria
• Unikota