1. Cell Differentiation & Cell Specialization

2. STEM CELLS

3. Stem Cells
HOW IS THAT POSSIBLE?

6. Sperm Cell Function: impregnate female egg cell Special structures:
Flagella – whips for movement
pointy head to break egg membrane
acrosome (packet of enzymes that break down egg membrane)
large mitochondria
for energy

7. Skin Cell Function: protect inner organs of organism
Special structures:
Flat & LOTS of layers
Waterproof
Different levels of organization-
Epidermis
Dermis
Muscle layer

8. Red Blood Cells Function: carry oxygen to all tissues in body
Special structure:
hemoglobin carries oxygen
disc shaped to carry the most oxygen!
no nucleus – more room for
hemoglobin

9. Muscle Cell Function: contract and relax for an organism’s movement
Special structures:
multi fibers to slide for movement
LOTS of mitochondria for more energy
Most mitochondria of
any cell type

10. Nerve Cell, Neuron
Function: Communicate and control ALL functions in an organism
Special structures:
Branched dendrites to receive message
long axon to send message
myelin sheath for protection

12. The Microscope Compound Light Microscope
Has two lenses – ocular (eyepiece) and objective
In order to be viewed, specimen must be thin (so the light may shine through the specimen) and placed on a slide.
Specimen may be stained to better see structures

13. Limitations of microscopes
1. Magnification is limited by the strength of the lens.
Calculating magnification:
Ocular lens x objective lens = total magnification
Example:
Ocular (10x) x objective (40x) = 400x
2. As magnification increases resolution (sharpness) decreases, so does Field of vision
LOW POWER
HIGH POWER

14. Field of Vision
As you increase magnification, you see more details of the specimen, but you see less of the overall specimen. This is called a reduction in the field of vision.
LOW POWER
HIGH POWER

15. Upside Down & Backwards?!?
The letter "e" is upside down because images under a compound microscope are always reversed and inverted. So when you go to move something to the right, it will be moving to the left. When you go to move something up, it will move down. Its the internal workings of the microscope (lens and mirror) that do this.
You put it under the microscope like this
But when you look at it… it looks like this?

16. What would the total magnification be on the microscope to the left?
Practice
What would the total magnification be on the microscope to the left?
Ocular
Objective
Total Magnification
20X 4X
10X
75X 5X
50X
25X
200X