1. All living things are made of .

2. The smallest living thing that we can call alive is a .

3. One of the students makes the suggestion that they should watch it closely under the microscope to see if it's alive. They say, "All living things move. If this object moves, it must be alive."

Which is the best evaluation of their argument?

• They are mostly correct. Only animals move, so the living thing could be a plant and be not moving.
• They are right. All living things change and grow, so if this is moving it must be a living thing.
• They are wrong, if we're looking at a group of cells. All organisms move, but single cells that are alone or a part of larger organisms do not move.
• They are mostly wrong. Some living things move, but others don't. If it's moving it could be a living thing, but might not.

4. Another student places some of the bread from their sandwich near these objects and leaves them overnight. The next day, they notice that some of the bread is gone and decide that these are living things and they ate the bread.

Which is the best evaluation of their argument?

• They are correct. All living things need energy and they must have eaten the bread.
• They are mostly wrong. Plants don't need energy or food, they survive off of heat from light. These could be plants.
• They are somewhat correct. Some living things eat food, but others don't need energy to survive.
• They are wrong. Some living things eat food, but others get energy in other ways.

5. The students watch with their microscope as some of the smaller pieces move around and the bigger pieces do not move. One of the students makes the following claim:

”This must be a group of different cells in a larger organism, since some of the smaller pieces are doing different things than the bigger pieces. Different cells do different jobs in living things.”

Which is the best evaluation of their statement?

• They are right. Groups of cells in multicellular organisms are always working together, but if different parts are doing different things, they are most likely single celled organisms.
• They are wrong. Larger organisms have different cells that do different things all the time and since some of these different objects are seen doing the same thing, they must be a single celled organism.
• They are wrong. Groups of cells in an organism might do different things or the same thing, but that doesn’t mean that they’re a part of a larger living thing.
• They are right. Groups of cells in all organisms usually work together to keep the organism alive. If cells are doing different things, they’re almost definitely a group of cells in a larger organism.