Lesson Plan Title : Growing Bacteria

Age Range:

Grade 6 through Grade 8 (Middle School)

Overview and Purpose:

Bacteria grow all around us. Learning about it can be fun and fascinating. In this lesson students will observe the growth of bacteria over a week's period.


The student will be able to

*identify areas in the classroom where bacteria are growing.

*observe and record the growth of bacteria growing in Petri dishes for one week.



Petri dishes with agar

Science journal


Explain that the students are going to swab their Petri dishes with material from different places in the classroom and illustrate the growth of bacteria over the next week. Brainstorm with the students some places where they think bacteria are growing in their classroom (i.e. the trash can, on the floor in the corner, between their toes).

Have them swab some of the areas and rub the Q-tip on the Petri dish. Label the dishes and check them each class period. Have the students illustrate the growth of the bacteria in the same Petri dish all week.

When the experiment is over, ask the students to tape the dishes closed and dispose of them in the trash. They should not open them.


An extension of this lesson would be to have the students research the type of bacteria that is growing and create a poster about it. They could also do a second experiment using common household cleaners. They could return to the areas and swab then again before and after they use a cleaner on them to see if that affects the bacteria growth.