Algae

Cyanobacteria

Which of the following is technically not algae but is often called “blue-green algae”?

They perform photosynthesis and live in aquatic environments

Why are cyanobacteria often mistaken for algae?

False

Seaweeds (macroalgae) are true plants.

Seaweed (macroalgae)

Which of the following is a plant-like protist that is not a true plant?

They are multicellular, grow underwater, and look like algae

Why are simple aquatic plants like Chara sometimes mistaken for algae?

They are prokaryotes and lack a nucleus and membrane-bound organelles

Why are cyanobacteria not considered true algae?

They have plant-like structures such as fronds and holdfasts

Why are seaweeds often mistaken for plants?

Algae are eukaryotes with a nucleus, while cyanobacteria are prokaryotes

Which feature distinguishes true algae from cyanobacteria?

Provide oxygen through photosynthesis

Cyanobacteria are important in aquatic ecosystems because they:

They are plant-like protists that absorb nutrients directly from water

Which of the following statements about macroalgae (seaweeds) is TRUE?

It is a simple aquatic plant (embryophyte)

Chara is not considered algae because:

They provide food for tiny aquatic animals

Cyanobacteria are important in the food chain because:

Nitrogen fixation

Which ability of some cyanobacteria helps plants grow better?

Pollution or excess nutrients (algal bloom)

Too many cyanobacteria in water can indicate:

Produce oxygen, provide food in water, fix nitrogen

Which of the following lists all the main benefits of cyanobacteria?

prokaryotic

Cyanobacteria is;

Green algae

Which algae are considered the closest relatives of land plants?

Red algae

Which type of algae is used to produce agar and carrageenan for food and lab purposes?

Brown algae

Which algae includes large seaweeds like kelp and is important for marine habitats and human food additives?

Diatoms

Which algae are major photosynthesizers in oceans and have silica shells used in filters and soil additives?

Cyanobacteria, Green algae, Red algae, Brown algae, Diatoms

Which of the following lists only significant algae important for oxygen production, food chains, and human use?

Produce oxygen and serve as food for aquatic animals

Green algae are important because they:

Produce agar and carrageenan for food and laboratory uses

Red algae are mainly used by humans to:

Provide habitat for marine life and are used in food additives

Brown algae, such as kelp, are important because they:

Produce oxygen, form the base of aquatic food chains, and have silica shells used in filters

Diatoms are significant because they:

Produce oxygen, support aquatic food chains, provide human food and industrial uses

Which of the following correctly lists the main purposes or benefits of algae?

Fucoxanthin

Which pigment gives Phaeophyta (brown algae) their characteristic color?

Brown algae

Phaeophyta is a scientific name for:

Chlorophyta

Which is the scientific name for green algae?

Rhodophyta

Which algae is also called red algae?

Phaeophyta

Which algae is commonly called brown algae or brown seaweeds?

Bacillariophyta

Diatoms are scientifically called:

(Dinophyta)

Dinoflagellates

Tiny, mostly microscopic, photosynthetic organisms in water

What are phytoplankton?

Diatoms and dinoflagellates

Which of the following are types of phytoplankton?

They produce a lot of oxygen and form the base of aquatic food chains

Why are phytoplankton important?

Oceans, rivers, and lakes

Phytoplankton live mostly in:

Produce oxygen / grow excessively and produce toxins

Algae are beneficial because they __________ and harmful when they __________.

Reduce oxygen in water, causing fish to die

Which of the following is a harmful effect of excessive algae?

Producing food additives like agar and carrageenan

Which of the following is a human use of algae?

They produce oxygen and form the base of the food chain

Why are algae beneficial to aquatic ecosystems?

By producing food (sugars) and oxygen through photosynthesis

How do zooxanthellae help their host animals?