How Quickly Can Bacteria Multiply? In this imaginary experiment, beans will represent bacterial cells. Put an imaginary bean in an imaginary cup. This bean will represent the first generation of bacteria.

Approximately every 20 minutes, a bacterial cell reproduces by dividing into two cells. Put 2 beans into a second cup to represent the second generation of bacteria.

Calculate how many bacterial cells there would be in the third generation if each cell in cup 2 divided into two cells.

Repeat previous step five more times. How many cells are in the eighth generation? How much time has elapsed since the first generation?

Cup 1 – 1 bacterium Cup 2 – 2 bacteria (20 min) Cup 3 – 4 bacteria (40 min) Cup 4 – 8 bacteria (60 min) Cup 5 – 16 bacteria (80 min) Cup 6 – 32 bacteria (100 min) Cup 7 – 64 bacteria (120 min) Cup 8 – 128 bacteria (140 min)

From one single bacterium, we got 128 bacteria in the eighth generation! And it only took 2h 20 min (140 min) !

Click “play” to view video.

The Bacterial Cell Structures Cell wall: rigid surrounding of bacterial cell that protects it Cell membrane: inside cell wall, controls what materials pass into and out of cell Cytoplasm: contains gel-like material

Ribosomes: tiny structures in cytoplasm, chemical factories where proteins are produced Genetic material: tangled string looking, inside cytoplasm, contains instructions for cell functions Flagella: long, whiplike structures that help a cell to move (singular flagellum)

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