ALGAE

Algae - What is it? Algae are plant-like organisms that belong to the Kingdom Protista.

Algae are a diverse group of protists Algae are a diverse group of protists. In other words they are all very different. For example, they may range in size from microscopic single-celled organisms . . . diatoms

to large seaweeds that may be hundreds of feet long. This is a picture of a kelp forest in the Pacific Ocean.

Most species of algae are unicellular, but some are large, multicellular organisms. These multicelluar algae are sometimes called seaweed.

Algae are autotrophic protists. They are called plant-like because they perform photosynthesis. Like plants they contain chlorophyll.

Algae are different from plants because they lack the specialized groups of cells (tissues) and have no true roots, stems, or leaves.

These root-like structures are called holdfasts. Can you tell why?

Algae reproduce in a way that is different from plants Algae reproduce in a way that is different from plants. Single-celled species reproduce by binary fission. Multi-cellular types may reproduce by conjugation.

Spirogyra, a green filamentous algae conjugates when strands line up and exchange genetic material. Spores form and drop to the bottom of the water.

In spite of the fact that organisms known as algae have many differences, they do have some characteristics in common. 1. They are mostly aquatic. 2. Most have flagella at some point in their life cycle. 3. Algae cells contain pyrenoids that make and store starch.

Algae is divided into 3 groups based on color: green, red and golden or brown. This is the green algae known as ulva or sea lettuce.

Red algae is called rhodophyta. Red algae can grow in very deep water.

This red algae known as Irish Moss is used as a stabilizer in many foods. You’ll find it listed as carageenan in your chocolate milk!

Green algae is called chlorophyta.

Brown or golden algae is phaeophyta. This algae is called fucus.

Many kinds of brown algae have bladders to help them float on the surface of the water - assuring them of a source of light. These are kelp bladders.