1. Cell Biology The big picture So tell me what you know about cells
So tell me why they are important
So tell me the purpose of cells
So tell me what’s inside a cell

2. Important questions What are cells? Why are they important?
What’s the purpose of cells?
What’s inside a cell?

3. What are cells
Cells are the basic unit of structure and function of living things.
You are made of trillions of specialized cells all working together.
There are plant cells as well as animal cells, the main difference between the two is that plant cells have a cell wall.

4. Why are cells important
Cells help keep living things alive
Some of the functions of cells are:
Obtaining oxygen
Getting rid of wastes
Obtaining food
Growth, repair, and reproduction
The length of time cells live can vary. For example, white blood cells only live for 2 weeks, red blood cells live for about four months, liver cells live about 1 year and 1/2, and nerve cells can live up to a life time.

5. What’s the purpose of cells
Cells help us stay alive and reproduce
Cells in your lungs provide oxygen for your body
Cells in your stomach provide energy by digesting food
Cells in your muscles protect your weaker organs
What’s the body's largest organ
Every minute, 40,000 dead skin cells fall from your body.
Over the course of life an individual sheds about 105 pounds of skin.

6. What's inside a cell Mitochondria Cytoplasm Ribosomes Nucleus
Endoplasmic Reticulum
Golgi Body
Cell membrane
Vacuole
Lysosomes
The one we as a class will focus on is the nucleus

7. Nucleus The nucleus is the “brain” of every cell
Every cell has a nucleus
Chromosomes are found inside the nucleus
The cell nucleus acts like the brain of the cell. It helps control eating, movement, and reproduction. If it happens in a cell, chances are the nucleus knows about it

8. Candy Question 100,000 In your groups answer the following question.
One square centimeter of your skin’s surface contains more than ________________ cells.
100,000
100,000

9. Purpose of cell division
The purpose of cell division is to take one cell and make two new identical “daughter” cells.  
Cells need to divide for reproduction, growth, and for repair.
What would happened if we could not repair our skin, organs, ect
Which cells do not reproduce naturally in the body? brain and nerve

10. Two types of cell division
Mitosis
Meiosis

11. Mitosis Mitosis happens in order to create new identical cells
Majority of cells under-go mitosis
Main purpose of mitosis is growth and repair
If mitosis is only for growth and repair, what kind of cells go through mitosis.

12. Mitosis 46 Parent Cell 92 DNA replicates 46 x 2 = 92 46 46
Yarn example 46 46
Two new identical daughter cells

13. Prophase Metaphase Anaphase Telophase
Chromosomes become visible, the nucleolus disappears.
Metaphase
The chromosomes become arranged in the center of the cell.
Anaphase
Chromosomes separate and then move to opposite sides of the cell.
Telophase
Chromosome reassemble at opposite sides of the cell and the nucleus reforms, around each set of chromosomes.

14. Meiosis Meiosis only occurs in sex cells
The only purpose for meiosis is for reproduction
The result of meiosis is four new cells with HALF the number of chromosomes.
Only in sperm in males and Eggs in females

15. Meiosis 46 Parent Cell 92 DNA replicates 46 46 DNA splits 23 23 23 23
DNA splits again

16. Compare and Contrast Mitosis and Meiosis
Alike
Different
Both are cell reproduction to make new cells
Both go through similar phases
Mitosis results in two new cells which has 46 chromosomes and happens in most cells.
Meiosis results in four new cells which has 23 chromosomes and happens only in sex cells.

17. Meiosis
Mitosis 46 46 92 92
How many vowels in the word Meiosis, how many steps in Meiosis 46 46 46 46 23 23 23 23

18. Using the plastic chips show me:
Mitosis
Meiosis
If you break your arm, what cell division takes place to repair the bone in your arm?
Which cell division creates human reproduction cells?
Represents the number of chromosomes 92 46 23

19. Review