1. Cell Specialization, Organization and Function

2. Cell Specialization
Cells specialize to carry out specific functions in an organism.
Cells come in a variety of shapes…
The shape of the cell is related to its function…

3. STEM CELLS Are unspecialized, jobless cells
In the lab, under the right conditions, scientists can manipulate stem cells to be come any cell type.
Stem cell have the ability to repair/heal any damaged, worn, or diseased cell.
Embryonic stem cells have the ability to become any cell type
Adult stem cells (small supply) do not have as many abilities as embryonic stem cells

4. Embryonic vs. Adult Stem Cells
Ability to develop into almost any type of cell in the human body.
Can replicate (multiply) at very large numbers.
Come from the destruction of an embryo or umbilical cord.
Ability to develop into limited types of cells.
Are unable to grow in large numbers.
Come from adult tissues, such as bone marrow.

5. How stem cells become specialized
The stem cells receive cues (instructions) from the DNA inside of the nucleus
The nucleus tells stem cells what cell type to become
The process by which stem cells become specialized (get a job) is differentiation

6. Differentiation
Multicellular organisms all begin as an undifferentiated mass of cells (embryo-blastocyst).
Variations in DNA and gene expression determine the function and structure of each cell as it becomes “specialized.”

7. Differentiation
Nearly all cells in a multicellular organism have exactly the same chromosomes & DNA. Because of this, all undifferentiated cells have the potential to become ANY type of cell.
Once a cell differentiates, it CANNOT be reversed!

8. Differentiation
During differentiation, only specific parts of the DNA are activated. The parts that are activated determine the function and structure of the specialized cell.
Different parts of the DNA are also used in different types of cells. This is influenced by the cell’s environment and past history.

9. Differentiation
Chemical signals may be released by one cell to influence the development and activity of another cell.

10. Human Red Blood Cells Notice the rounded shape of red blood cells
What is the function of red blood
cells?
Carry O2
How does the rounded shape help Red blood cells do their job?
Rounded shape helps blood cells move easily through blood vessels

11. Bone Cells
Notice the “tree-ring” pattern of bone cells What is the function of bone cells? Provide protection to soft tissue & organs
How does the shape of bone cells help its function?
Forms a network of strength to provide protection

12. Nerve Cells What is the function of nerve cells?
Communication; receiving & transmitting info through the body from organ to organ
How does function relate to shape?
Long thin “fibers” for transmitting information

13. Muscle Cells What is the function of muscle cells? Movement
How does its shape relate to its function?
Muscle cells are long & elastic to allow for contraction & expansion which creates movement

14. There are 3 types of muscle cells
CARDIAC
SKELETAL
SMOOTH

15. Sperm Cells
What is the function of sperm cells? Fertilize the female egg How is their shape related to their function? Have long tails (flagella) to swim to egg

16. Plant transport tissue- Xylem
What is the function of the xylem?
To transport water and minerals from roots to top of plant.
How does its shape relate to its function?
Tube shape with no interference which allows for continuous water flow.

17. Plant transport tissue- Phloem
What is the function of the phloem?
Transports food and nutrients form the leaves to storage areas.
How does its shape relate to its function?
Long tube shapes with sieve walled tubes inside. Allows for up and down movement of material.