Lesson 4 - Microorganisms: Protozoa and Algae

Introduction

Today we’ll discuss protists (protozoa) and algae. Protists are one-celled organisms that feed on bacteria, dead matter, and even other protists. Some use flagella, which are whip-like threads, to push themselves around. Others use different ways to move. Most of these one-celled organisms live in wet places, such as oceans, lakes, ponds, rivers, and streams. Some protists behave like animals; others seem like plants. But they are actually none of the above. They belong to their own kingdom.

Algae are living creatures that like to live in moist environments. Algae, like land plants, feed themselves through the process of photosynthesis. Although algae use photosynthesis to prepare their food, they are not plants. There are no leaves, stems, flowers, or seeds on them. Some algae only have one cell. Some smaller algae species can only be seen under a microscope, while others, such as giant kelp, can be seen with the naked eye and are over 180 feet long. Algae play significant a role in the food web. Animals including whales, octopuses, starfish, and many other types depend on them for food. In some countries, it is also used as a human food source.

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Protozoa and Algae

Directions: 

1. 1. Grab your Science Journal and a pencil.
   2. Write down today’s Lesson Title at the top of your next Journal page.
   3. Write today’s learning objective on the first line.
   4. Watch the Module 3 - Lesson 4 video below. 
   5. Write down the important terms and their definitions in your Science Journal.
   6. Pause the video as often as you need.

 

 

   

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