Sam and Carol tried a second experiment. Carol and Sam took a package of yeast and poured it into some warm water. Yeast is used when baking bread to help the bread to rise. After an hour, they noticed that the yeast solution was bubbling. They used a dropper to make a microscope slide of some of the liquid containing the yeast. This is what they saw.

Carol thought what yeast was a living thing. Sam thought she was wrong. But is it?