Algae and Their Ecological Importance

Marine algae are vital to Earth's ecosystems, providing oxygen and supporting marine life. They are categorized into red, green, and brown algae, each with unique characteristics and ecological roles. Red algae thrive in deeper waters due to phycoerythrin, green algae are diverse and help reduce CO2, and brown algae are large and antioxidant-rich. Algae support coral reefs and can be used as biofuel, producing significant oxygen through photosynthesis.

What are the basic characteristics that differentiate marine algae from typical plants?

• They lack roots, shoots, and leaves.

• They produce seeds and flowers.

• They have vascular tissue.

• They have roots and leaves.

Which pigment is responsible for the red color in red algae?

• Xanthophyll

• Chlorophyll

• Carotene

• Phycoerythrin

What is a common use of red algae in commercial products?

• As a source of chlorophyll

• For producing agar

• For making biofuel

• As a natural dye

Which type of algae is most diverse with over seven thousand species?

• Red algae

• Brown algae

• Blue-green algae

• Green algae

What role does chlorophyll play in green algae?

• It gives them a red appearance.

• It helps them absorb blue light.

• It makes them float.

• It gives them a green appearance.

What is a characteristic feature of brown algae?

• They have a holdfast structure.

• They are mostly found in tropical waters.

• They lack air bladders.

• They are microscopic.

Which type of algae is known for its antioxidant and anti-inflammatory properties?

• Green algae

• Red algae

• Blue-green algae

• Brown algae

How do algae contribute to the well-being of coral reefs?

• By producing coral skeletons

• By reflecting sunlight

• By supplying necessary compounds for coral growth

• By providing a habitat for fish

What is a potential benefit of using algae as a biofuel?

• It is not sustainable.

• It can produce 15 times more oil per acre than corn.

• It is already a large-scale operation.

• It produces less oil than corn.

What percentage of the Earth's oxygen is produced by algae?

• 30%

• 50%

• 70%

• 10%