Algae: Aquatic Origins

How are algae related to true plants?

Green algae are closely related to true plants, and bryophytes and vascular plants likely descended from an extinct member of the green algae lineage.

Are all algae closely related to true plants?

No. Different types of algae have different evolutionary relationships.

Why are algae not considered one single kingdom?

Molecular phylogenetics shows that different algae are related to different groups of organisms.

What is the scientific group name for green algae?

Chlorophyta.

What pigments do green algae have?

Chlorophyll a and chlorophyll b.

Why do green algae appear green?

Because they contain lots of chlorophyll a and b.

Where can green algae be found?

In marine and freshwater ecosystems.

How are green algae related to land plants?

Land plants likely descended from an extinct member of the green algae lineage.

What groups of plants likely descended from the green algae lineage?

Bryophytes and vascular plants.

Where are red algae commonly found?

Warm marine waters.

What chlorophylls do red algae use?

Chlorophyll a and chlorophyll d.

What pigment makes red algae appear red?

Phycoerythrin.

What is a possible origin of red algae?

They may have originated from cyanobacteria.

Can red algae have alternation of generations?

Yes, their life cycles can include alternation of generations.

What are brown algae known for?

They are often multicellular and structurally complex.

What is a common example of brown algae?

Kelp

What are the three major structures of kelp?

Holdfast, stipe, and blades.

What does the holdfast do?

Anchors the kelp to a surface.

What does the stipe do?

Provides stem-like support.

What do the blades do?

Carry out photosynthesis.

Are all dinoflagellates photosynthetic?

No. Some are photosynthetic and some are heterotrophic.

What are zooxanthellae?

Single-celled dinoflagellates that live in a symbiotic relationship with coral.

What do zooxanthellae do for coral?

They perform photosynthesis and provide energy to the coral.

What can happen to zooxanthellae when coral is stressed by high temperatures?

The coral can lose its zooxanthellae, causing coral bleaching.

Can some dinoflagellates be harmful?

Yes. Some can cause toxic algal blooms, such as red tides.

What dinoflagellate is associated with red tides in your notes?

Karenia brevis.