1. 1. All living things are made up of one or more cells Is yeast unicellular or multicellular?

2. 2. All living things are organized Yeast cells are eukaryotic, which means they have a membrane bound nucleus and membrane bound organelles. Is a yeast cell organized?

3. 3. All living things grow and develop Yeast cells produce a new generation of cells in about two hours. Each cell undergoes the cell cycle (pictured below). Does yeast experience growth and development?

4. 4. All living things obtain and use energy (metabolism) The yeast which is used to make bread is Saccharomyces cerevisiae. This yeast is a facultative anaerobe, which means that when oxygen levels are low or glucose levels are high, sugar is metabolized without using oxygen, resulting in the production of a small amount of ATP (energy), as well as carbon dioxide and ethanol. As the bread bakes, the ethanol evaporates. Bubbles which contained carbon dioxide provide the fluffy texture of bread. S. cerevisiae and other members of the same genus are used in making wine and beer, where, obviously, the production of alcohol is a major goal. (Source - serendip.brynmawr.edu/sci_edu/waldron/pdf/YeastTeachPrep.doc)

5. 5. All living things maintain homeostasis Yeast cells are able to regulate their metabolism to maintain internal balance. Does yeast experience homeostasis?

6. asexual reproduction sexual reproduction 6. All living things have the ability to reproduce, pass on their traits, adapt to their environment, and experience evolution

7. 7. All living things respond to their environment Yeast cells are able to control the expression of their genes when experiencing environmental stress. This gene regulation is referred to as the environmental stress response. For example, yeast cells are able to regulate their internal conditions and gene expression to survive an exposure to high temperatures. Does yeast experience response?