A hypothesis is a general principle or explanation that is derived from observations. Suppose you make the following observations: a. You look at 10 human liver cells and observe that each one has a nucleus. b. You look at 10 onion cells and observe that each one has a nucleus. c. You look at 10 nerve cells from a mouse and observe that each one has a nucleus.

For each statement below, mark "True" if it would be a valid hypothesis, based on these three observations alone, and mark "False" if it would not be a valid hypothesis.

1. The onion cells I looked at have a nucleus.

2. All onion cells have a nucleus.

3. All cells have a nucleus.

4. Some cells have a nucleus.

5. Only onion cells have a nucleus.

6. If I look at 10 skin cells from my hand, each one will have a nucleus.

Answer:

1. The onion cells I looked at have a nucleus. false - this is not a hypothesis, it is an observation of the evidence you collected.

2. All onion cells have a nucleus. true - this is a valid hypothesis based on the evidence you have gathered from looking at onions

3. All cells have a nucleus. true - this is a hypothesis based on you looking at 3 cell types, several samples of each, and finding that they all have a nucleus

4. Some cells have a nucleus. false - this is not a valid hypothesis. Your evidence so far suggests all cells have a nucleus

5. Only onion cells have a nucleus. - false, you know this to be false as other cell types you analysed had a nucleus

6. If I look at 10 skin cells from my hand, each one will have a nucleus. false - a hypothesis is supposed to be a general principle that is backed up by evidence, this is too specific.