1. Specialized Cells Are they all alike?

2. Maryland Science Content Standards Describe and explain that the complex set of systems found in multicellular organisms are made up of different kinds of tissues and organs which are themselves composed of differentiated cells.

3. Notebook Title:Cell Type Date:12/16/2009

4. Objective Students will be able apply the concept of cell division to hypothesize whether cells are identical in shape and function throughout the body

5. Your Thoughts What do your cells look like? Why do you think this? What are the function of cells?

6. BUT…… We came from only two cells, that split into identical cells, right????? –What do you think????

7. Let’s Check This Out Click here

8. What Type of Cells Do We Have? What types of cells do you have? What do they look like? Why do you say this?

9. Let’s Keep Going…… How do multicellular organisms get nourishment, water, and oxygen and get rid of wastes? If all multicellular organisms start from a single cell -- the fertilized egg -- how do they develop specialized tissues, organs, and systems like the heart and circulatory system, the stomach and digestive system, and the kidneys and excretory system?

10. The Science Behind the Specialty The majority of organisms consist of many more than one type of cell. Indeed, about 200 different types of cells -- many highly specialized -- make up the tissues and organs of the human body. The cells that line the retina of your eye, for example, have a structure and function that is markedly different from those of the muscle cells in your bicep. Information taken from: http://www.teachersdomain.org/resource/tdc02.sci.life.stru.different/

11. Stem cells begin their transformation into the different types of cells that make up the human body during a phase in the development process called cell differentiation. In vertebrates, differentiation begins during a stage called gastrulation, when distinct tissue layers first form. Like most other developmental processes, differentiation is controlled by genes, the genetic instructions encoded in the DNA of every cell. Genes instruct each cell how and when to build the proteins that allow it to create the structures, and ultimately perform the functions, specific to its type of cell. The Science Behind the Specialty

12. Surprisingly, every nucleus of every cell has the same set of genes. A heart cell nucleus contains skin cell genes, as well as the genes that instruct stomach cells how to absorb nutrients. This suggests that in order for cells to differentiate -- to become different from one another -- certain genes must somehow be activated, while others remain inactive. Although scientists have come a long way toward understanding how cells coordinate the well-timed activation and inactivation of their genes, researchers have had little success inducing these changes artificially. Gaining such control over the developmental process, experts believe, may eventually result in cures for a wide variety of diseases, including diabetes and cancer. The Science Behind the Specialty

13. This Is the Process Click here This video segment from NOVA: "Life's Greatest Miracle"

14. Group Work In groups, you will research one of the following: –Nerve cellNerve cell –Red blood cellRed blood cell –White blood cellWhite blood cell –Muscle cellMuscle cell –Skin (epithelia) cellSkin (epithelia) cell –Bone cellsBone cells

15. Big Group Trace a group member’s body on large poster paper Each member of the bigger group draw the cells in the location they belong and write the function of the particular cell

16. Final Thought Organisms grow due to cell division. DNA is replicated. Every body cell has the same DNA. What happens during cell division that allows the DNA of cells to be the same, but the shape and function to be different?