1. “CELL REPRODUCTION” (p.96)
CHAPTER FOUR
“CELL REPRODUCTION”
(p.96)

2. CHAPTER 4 “I Cans” I can state the reasons why mitosis occurs.
I can state the reasons why mitosis occurs.
I can draw and explain the phases of mitosis.
I can identify the properties of a DNA strand.
I can discuss different types of current DNA research.

3. Cell Reproduction is also known as cell division
or mitosis or fission.

4. REASONS FOR MITOSIS Growth -adding cells to the body. Replace
worn-out or dying cells.
Ex. Red blood cells (2-3 million per second).
Repair
bruises and cuts.
Reproduction *
- one celled organisms.

5. ------------------------------------------------ Parent cell
the original cell.
Daughter cells
- the two new cells that are formed
Parent Cell
Daughter Cell

6. Mitosis Humans: 46 Fruit Flies: 8 Cat: 32 Potato and Chimp: 48
- a type of cell division which produces daughter cells exactly like the parent.
New cells must have the same number of chromosomes. The DNA must be duplicated.
Humans: 46
Fruit Flies: 8
Cat: 32
Potato and Chimp: 48

7. MITOSIS is a series of changes or phases

8. 1) INTERPHASE
WHEN THE CELL IS NOT DUPLICATING.
NORMAL CELL ACTIVITIES.
MOST OF A CELL’S LIFE IS SPENT IN INTERPHASE.

9. Time spent in the Cell Cycle
4 hours
10 hours
2 hours
4 hours

10. 2) PROPHASE- first real stage of mitosis.
Nucleus breaks apart.
-nuclear membrane disappears
Tube-like structures called spindle fibers appear and attach to the centrioles.

11. 3) METAPHASE
Spindle fibers attach to the chromosome at their middle point.
- called a centromere.

12. 4) ANAPHASE
Centrioles and spindle fibers pull apart the chromosomes to opposite sides of the cell.

13. 5) TELOPHASE Centriole and spindle fibers disappear. Nucleus reforms.
Chromosomes have duplicated.
Cell membrane pinches in to form two daughter cells.

14. After telophase, cells enter interphase again.

16. Mitosis Animation

17. IDENTIFY THIS STAGE OF MITOSIS
INTERPHASE

18. IDENTIFY THIS STAGE OF MITOSIS
METAPHASE

19. IDENTIFY THIS STAGE OF MITOSIS
IT’S A TOUGH ONE….
PROPHASE

20. IDENTIFY THIS STAGE OF MITOSIS
ANAPHASE

21. IDENTIFY THIS STAGE OF MITOSIS
TELOPHASE

22. In plants, a new cell wall - called a cell plate - forms between the daughter cells.

25. ASSIGNMENT: WORKSHEET “MITOSIS”

26. DNA - “deoxyribonucleic acid”
a chemical which makes up the chromosomes.
Key to heredity.
Duplicated during mitosis.

27. Its structure and how it works was a mystery until 1952.
James Watson and Francis Crick
-proved the shape/structure of DNA was a double helix. (twisted ladder) p.111

28. The DNA molecule is made of four chemicals put into a certain order.
Base pairs
Guanine Cytosine
Adenine Thymine
the sequence forms the hereditary code.
it controls eye color, height, allergies, etc.

29. The siderails are made of a sugar – deoxyribose – and a phosphate.
What would happen if we would change the base pairs?

31. A section of the chromosome called a gene determines traits.
Ex. blonde hair, blue eyes, etc
- a gene is the location of a protein which makes your code.

32. DNA is duplicated during mitosis
called replication.
sometimes an error occurs (caused by pollution or x-rays) called a mutation.
- a permanent change in the gene.
- most are harmful.
ex. deformed frogs in Minnesota.

34. Mutations

35. DNA Research Recombinant DNA
new DNA created when DNA from one organism is combined with another organism.
also called “gene splicing”.

36. This has created “new” organisms.
oil eating bacteria.
Disease resistant potatoes.
Insulin producing bacteria.
“Round-up ready” corn

38. What if we could replace the DNA strand which causes cancer?
Many are against DNA research. We could create a very deadly disease.

39. a clone is genetically identical to its parent.
Cloning
a clone is genetically identical to its parent.
The DNA comes from one parent - not two.
Good? Bad?
Dolly

40. Cloning

41. ASSIGNMENT: WORKSHEET “DNA”

42. CHAPTER 4 “I Cans” I can state the reasons why mitosis occurs.
I can state the reasons why mitosis occurs.
I can draw and explain the phases of mitosis.
I can identify the properties of a DNA strand.
I can discuss different types of current DNA research.