Bacterial Reproduction

Lesson Plan - Get It!

Audio:

Bacteria can reproduce as quickly as every 20 minutes, which allows for exponential growth because of how they reproduce.

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

You may wonder what the difference between a bacterium and a bacteria is. 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.

Before you continue, if you missed, or need to review, the previous seven lessons in this Viruses and Bacteria series, find them under Related Lessons in the right-hand sidebar.

Asexual reproduction is when there is only one parent involved, and the offspring is identical to the parent. The bacterium makes an exact copy of itself.

Bacteria reproduce asexually by binary fission, one cell dividing in half to form two identical cells. There are five stages that the bacterium goes through during this process.

1. In Stage One, the bacterium makes an exact copy of its DNA.

2. During Sage Two, the bacterium cell grows longer, allowing the two DNA molecules to separate.

3. Next, in Stage Three, a cross wall (also called a septum) begins to form in the middle, and the membrane invaginates, or turns inward, and encloses the new cell in Stage Four.

4. Finally, after the septum has fully formed, the two cells separate into two new daughter cells for Stage Five.

Sexual reproduction is when there are two parents involved, and they combine their genetic material to form an offspring that differs from both parents. However, sexual reproduction in bacteria does not result in additional offspring.

Instead of more offspring, it results in more genetic diversity, which is passed on to new bacteria when they divide by binary fission.

Genetic material diversity can be achieved by the three ways listed below.

Bacterial conjugation

When a plasmid is shared from one bacterium to another, this creates no new bacteria, but it introduces some genetic diversity into the population.

Bacterial transformation

When bacteria pick up a plasmid from the environment, this creates no new bacteria, but it introduces some genetic diversity into the population.

Bacterial transduction

When a virus moves bacterial DNA from one bacterium to another via viral replication cycles, this creates no new bacteria. Still, it introduces some genetic diversity into the population.

As you watch the video below, fill out Lesson Eight, Bacterial Reproduction, in your Viruses and Bacteria Unit Workbook that you downloaded in Lesson One from Downloadable Resources in the right-hand sidebar.

Write all your vocabulary words down in the vocabulary section of the workbook.

Binary fission results in more bacteria, but conjugation, translation, and transduction increase genetic diversity among the bacterial cells.

Think about how one bacterium can turn into many bacteria in a short period.

• Why do you think it is beneficial for the bacteria to be able to pass on new genetic material to other bacteria?

In the Got It? section, you will become the teacher!