Bountiful Bacteria

Contributor: Felicia Sabur. Lesson ID: 11415

Bacteria are everywhere! Does that seem good or scary to you? These amazing little creatures reproduce faster than you can say "binary fission and conjugation"! See if you know "beans" about bacteria!

categories

Life Science

subject
Science
learning style
Visual
personality style
Lion
Grade Level
Middle School (6-8)
Lesson Type
Quick Query

Lesson Plan - Get It!

Audio:

Bacteria can reproduce as often as every 20 minutes! Happily for us, certain conditions have to be just right in order for them to multiply this quickly. How many bacteria do you think we would have after four hours if conditions were right, if we start with one bacterium?

Just like all living things, bacteria reproduce.

They can reproduce by both asexual reproduction and sexual reproduction by conjugation.


Asexual reproduction is when there is only one parent involved and the offspring is identical to the parent. It's kind of like the bacterium makes a photocopy of itself.

While watching the Asexual Reproduction by dickychin8282 video below, you will learn more about asexual reproduction. You will also get to see what bacteria look like under the microscope as they multiply asexually:

 

Bacteria reproduce asexually by binary fission, the process of one cell dividing to form two identical cells. There are four stages that the bacterium go through during this process.

Before watching the next video, MicroShorts Binary Fission by Rebecca Payne Microbiology, print the How Bacteria Multiply Worksheet found in Downloadable Resources in the right-hand sidebar. Feel free to pause or replay the video while filling out the section on Binary Fission:

 


Sexual reproduction is when there are two parents involved and they combine their genetic material to form an offspring that differs from both parents.

During the process of conjugation, one bacterium transfers some of its genetic material to another bacterium. In order to do this, the bacteria form a bridge-like structure called a pilus that connects the two cells. This process changes the genetic material of the cells, but it doesn't increase the number of bacterium. When these cells divide asexually through binary fission, the new genetic material passes to all new bacteria cells that are formed.

To explore the conjugation process more fully, watch this animated video Bacterial Conjugation by Anirban Basu:

 

NOTE: If there's only one, you call it a bacterium, and if there are more than one, you call them bacteria. The word "bacteria" is the plural form of bacterium.

Discuss with your teacher and classmates how one bacterium can turn into many bacteria in a short period of time, and why you think it is beneficial for the bacteria to be able to pass on new genetic material to other bacteria.

Continue on to the Got It? section for a simple experiment!

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