Living things with one cell

What this chapter teaches

Some living things are one cell. Yeast has a nucleus, and bacteria have none. Most microbes are harmless or useful, and a few cause disease. A virus is not a cell. Yeast makes carbon dioxide gas that makes dough rise.

Three questions to ask

There is no one right wording. Listen for the idea.

1. Which living thing can you name that is made of only one cell?
2. Why does dough with yeast in it rise?
3. How can you keep disease microbes away from your food and hands?

After the chapter, the learner can

• Name living things made of one cell, such as yeast and bacteria
• Explain how some microbes cause disease and others are useful
• Make bread dough rise with yeast and explain why it rises