Bacteria lab

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Biology Lab Report
Bacterial Growth

To determine how temperature affect bacterial growth.

We think bacteria will well grow in 37℃, because that is close to our bodytemperature. In our body many bacteria are living so temperature is good for them. We choose three bacteria which are from soil, saliva, and hand wash water. Saliva and hand wash water is something that relatedto our body. We choose soil because our hypothesis is 37℃ and soil is at outside. So we want to see what temperature does it grow the most which usually lives at outside. We think when thetemperature is too low or too high bacteria will die.

Independent: Independent variable of this experiment is temperature which is changed by experiment.
Dependent: Dependent variable of thisexperiment is bacterial growth which I want to find out during experiment.
Control: Control variable of this experiment is

-Bacteria -96% alcohol
-Beaker -Petri dishwith nutrient agar
-Test tube -Bunsen burner
-Disinfectant -Inoculating loop
-Permanent marker

1. You work with pairs. You prepare everything on the desk.
2.You pour alcohol to the test tube. You light the Bunsen burner.
3. Before you work with microbes you wash your hand and swab the bench with disinfectant. You put name on the lid of Petri dish.4. You heat edge of the test tube (which is alcohol in it) for 2 seconds. Dip the inoculating loop and heat it until it gets red.
5. You heat edge of the bottle/beaker which has bacteria init. Dip the inoculating loop.
6. Slightly lift the lid of Petri dish. Gently streak the loop over the surface of the ager and replace the lid.
7. You steal the Petri dish with tape. Put the dishupside down. You wait for two weeks.
8. Repeat step 2-7 for other two Petri dishes. You place them to different places.
9. Leave it for 2 weeks.

Our result from Petri dish is at...