Bacterias are prokaryote organism, that means they have not nucleus.

They are the mayority of cell in your body.

We can separate it in Bad and good:

Bad: tuberculosis, lyme disease (bacterial infections)

Good: yogurt, gut

We have a great quantity of bacterias in our body beacause:

1 human cell is 20 bacterias in us.

This is the quantity of human cells and bacterias in our body:

–  10 – 100 trillion human cells

– 200-2000 trillion of bacterias.

The main difference between Eukarya and Bacterias:

http://youtu.be/fZEmF1hzHIs

How are they?

How they reproduce—by binary fision:

The DNA breaks in two.

http://youtu.be/WYe0LWTyEJM

Mutations:

This consist of one bacteria pass to another one what the other do not have. So the get stronger:

You can see it in this video.

http://youtu.be/_75VW3zzQSc

Antibiotics:

They kill bacteria

They were discovered by Alexander Fleming

How he discovered them:

1st: He used a Petri dish. He discovered that some kind of bacteria was growing inside.

2nd:Later in one of his petri dishes, in the center was growing a mold, the fungi can not get close to them.

This substance was called PENICILLIN.

Now there are lots of Antibiotics coming from different sources.

http://www.slideshare.net/Alvarolafuente/bacterias-10676438