Bacteria and ArchaeaChapter 10 section 1

Warm upWhat is the difference between the two pictures in the following figure?

Objectives Define prokaryote.Describe the characteristics of prokaryotes.Explain how prokaryotes reproduce by binary fission.Recognize three common shapes of bacteria.Explain the importance of the endospore.

Introduction How many bacteria are in a handful of soil? Would you believe that a single gram of soil- which is about the mass of a pencil eraser- may have more than 2.5 billion bacteria? What about a handful of soil?

Name some characteristics that you know about prokaryotic cells.

Single-celled organismsNo nucleusVery small but not all of the same sizeDNA (genetic material) scattered in the cytoplasmHave cell wall that gives them their specific shape.Bacteria are mostly of three common shapes: rod shape, spherical shape and spiral shape.

Shapes of bacteriaMost bacteria have a rigid cell wall that gives them their shape.3 common shapes of bacteria:

1- Bacilli: rod shaped2- Cocci: spherical shape3-Spirilla: spiral shapeSome bacteria have hair-like parts called flagella that help them move around.

No Nucleus!All bacteria are single-celled organisms that do not have no nucleus. They are known as prokaryotes.A prokaryote is able to move, get energy and reproduce like cells that have a nucleus.Prokaryotes function as independent organism

Prokaryote ReproductionProkaryotes reproduce by a process called Binary Fission.Binary fission is a reproduction in which one single-celled organism splits into two single-celled organisms.

Endospores

Most species of bacteria do well in warm, moist places.Some will die in cold surroundings.Some bacteria becomes inactive in cold surroundings and form endospores.An endospore contains genetic material and proteins and is covered by a thick, protective coat.Scientists found endospores inside an insect that was preserved in amber for 30 million years.

Wrap up with Homer

What are prokaryotes?How bacteria differs from other eukaryotic cells?What are the three common shapes of bacteria?How can bacteria reproduce?What is an endospore?

AssignmentsSection review questionsPractice sheetSystem-wide Quiz 1

Required lessons are:

5.1 Mendel and his Peas5.2 Traits and Inheritance10.1 Bacteria and Archaea