Diatoms: Characteristics and Ecology

The video introduces diatoms, a major group of algae and common phytoplankton. Diatoms are unicellular organisms with glass cell walls, belonging to the kingdom Protista. They are found in various water bodies and are crucial as primary producers, contributing significantly to oxygen production. Diatoms exist in two forms: Centrales, with radial symmetry, and Pennales, which are elongated. They play a vital role in aquatic ecosystems by providing food and oxygen. The video concludes by emphasizing their ecological importance.

What type of organism are diatoms?

• Multicellular

• Unicellular

• Bacteria

• Fungi

What material are diatom cell walls made of?

• Glass

• Chitin

• Cellulose

• Protein

Approximately how many species of diatoms have been discovered?

• 50,000

• 500,000

• 100,000

• 10,000

What do diatoms need for photosynthesis?

• Sunlight, oxygen, and water

• Sunlight, carbon dioxide, and water

• Sunlight, nitrogen, and water

• Sunlight, carbon dioxide, and oxygen

Which form of diatoms has radial symmetry and is wheel-shaped?

• Centrales

• Both

• Pennales

• Neither

Where are Pennales most commonly found?

• Mountains

• Deserts

• Freshwater streams

• Oceans

What is one of the ecological roles of diatoms?

• Decomposers

• Primary producers

• Parasites

• Predators