Lab 9: Autotrophic Protists - The Eukaryotic Algae
Algal Classification

(D) Cell Walls Composition and Construction

Like the higher plants, many algae have cellulose as part of their cell wall. The cell wall is constructed of microfibrils of cellulose with the microfibrils intertwined and criss-crossed in layers, like a sheet of plywood. Cell walls are difficult to observe in algae as they are clear and rather thin compared to cell walls in plants. Stains are used to distinguish cell walls and a few prepared slides may be available for demonstration on the front desk.

In addition to cellulosic cell walls, algae have a number of other compounds used in cell wall construction. Euglena and Chlamydomonas have proteinaceous materials in their cell walls. The cell wall material in Euglena is arranged in a spiral pattern around the cell and is called a pellicle. This flexible wall allows it to move freely in the bottom mud of ponds and lakes.

Calcareous alga
Calcareous alga
Calcareous alga

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