Mr.Finley Science Period 8

In this science period we discussed our petri dishs and the growth of bacteria in them. We also talked about how to chart them and find out how to graph the amount of growth and how much there is so far. We also talked about looking at bacteria percent and fractions the guesses were...

• 10%
• 1/7
• 15%
• 20%

We all assumed that 1/5 was the best fraction guess. Mr.Finley like fractions the best so that was what we used. You have to divide that to find the amount of percent of the growth of bacteria. Most students go this concept.

Each group also checked thier bacteria samples for the second day so far. Yesterday, many groups didn't get a lot of bacteria since it was only the first day of their growth time. Since today is the second day, more groups had more growth. This means that each group could record their quanitative data. If you were wondering, quanitative data is when the groups record what their bacteria looks like. So if their bacteria was green and lumpy, they would record that. The groups have to remeber to record guessed percentages as fractions. They also have to remember that their "bacteria" could be mold, the students have be very specific and careful with that kind of detail.

If the "bacteria" is hairy, it is mold. But if it looks like a melted piece of vanilla, it is bacteria. Most groups could have gotten a lot of mold, but you can never be too sure.

For example, my group only got bacteria in the sample for the high school gym floor. We used the mold in our data since we were allowed to. Mold is allowed in recorded data. Here were our results.... We only got some bacteria/mold for the high school gym floor

• Llyod said 15%
• Carter said 10%
• Lexi said 11%
• And I said 8%
• Our average result was 11%

Our qualitive data for the gym floor was.....

• Some of it was mold
• All dots of bacteria
• A big clump of mold

After we looked at our samples, Mr.Finley started talking about dependent and independent varibles. Here are the definitions of indpendent and dependent varibles...

Independent Varible: The independent varible in this experiment is testing

Dependent Varible: The dependent varible in this experiment is the bacteria

Next, the class made line graphs on the growth of the bacteria

MM