Primary Producers of the Ocean '26

Why are algae not considered to be plants?

• It is not green all the time

• It floats.

• It does not have roots, vascular tissues nor flowers

Which seaweed is a true plant and NOT an algae

• 
• 
• 
• 

the stem-like portion of then of seaweeds

• thallus

• blade

• stipe

• pneumatocyst

• holdfast

The portion of the seaweed that attaches to a substrate, like rocks, is the

• thallus

• pneumatocyst

• stipe

• holdfast

• blades

pneumatocysts are

• root-like structure of seaweeds

• leaf-like structure of seaweeds

• stem-like structure of seaweeds

• gas-filled bladders that sometimes keep their blades close to the sea surface

• stipe

• blade

• holdfast

• pneumatocyst

body of seaweed

• stipe

• macroalgae

• thallus

• blade

What is the term used to describe a sudden increase in phytoplankton growth? 

• A Spring

• A Migration

• A Bloom

• A Flower

What is one reason that phytoplankton are important?

• they clean the water

• they sequester CO₂

• they are drifting animals

• they make the water warmer

Which of the following phytoplankton are able to move using flagella?

• Dinoflagellate

• Diatoms

• Coccolithophores

• Cyanobacteria