1. The Cell Cycle & Cell Division

2. The Cell Cycle

3. Phases of the Cell Cycle
The cell cycle consists of
Mitotic (M) phase (mitosis and cytokinesis)
Interphase (cell growth and copying of chromosomes in preparation for cell division)
Interphase (about 90% of the cell cycle) can be divided into subphases:
G1 phase (“first gap”)
S phase (“synthesis”)
G2 phase (“second gap”)

4. Animated Cycle

5. MITOSIS

6. Mitosis
The process of cell division which results in the production of two daughter cells from a single parent cell.
The daughter cells are identical to one another and to the original parent cell.

7. Mitosis can be divided into stages
Interphase
Prophase
Metaphase
Anaphase
Telophase & Cytokinesis

8. Interphase The cell prepares for division
Animal Cell
DNA replicated
Organelles replicated
Cell increases in size
Plant Cell
DNA replicated
Organelles replicated
Cell increases in size

9. Interphase Plant Cell Animal Cell
Photographs from:

10. Prophase The cell prepares for nuclear division
Animal Cell
Packages DNA into chromosomes
Plant cell
Packages DNA into chromosomes

11. Prophase Plant Cell Animal Cell
Photographs from:

12. Metaphase The cell prepares chromosomes for division
Animal Cell
Chromosomes line up at the center of the cell
Spindle fibers attach from daughter cells to chromosomes at the centromere
Plant Cell
Chromosomes line up at the center of the cell
Spindle fibers attach from daughter cells to chromosomes at the centromere

13. Metaphase Plant Cell Animal Cell
Photographs from:

14. Anaphase The chromosomes divide
Animal Cell
Spindle fibers pull chromosomes apart
½ of each chromosome (called chromotid) moves to each daughter cell
Plant Cell
Spindle fibers pull chromosomes apart
½ of each chromosome (called chromotid) moves to each daughter cell

15. Anaphase Plant Cell Animal Cell
Photographs from:

16. Telophase The cytoplasm divides
Plant Cell
DNA spreads out
2 nuclei form
New cell wall forms between to nuclei to form the 2 new daughter cells
Animal Cell
DNA spreads out
2 nuclei form
Cell wall pinches in to form the 2 new daughter cells

17. Telophase Plant Cell Animal Cell
Photographs from:

18. Mitosis Animation

19. Animal Mitosis -- Review
Interphase                                                             
Prophase                                                             
Metaphase                                                             
Anaphase                                                             
Telophase                                                             

20. Plant Mitosis -- Review
Interphase                                                             
Prophase                                                             
Metaphase                                                             
Anaphase                                                             
Telophase                                                             

21. Asexual Reproduction
Living Environment

22. Mitosis animation:

23. Are you two twins? Asexual Reproduction:
Used by many unicellular organisms, plants, and lower animals.
Involves only mitotic cell division = each offspring has exactly the same heredity as its parent.
Usually rapid compared to sexual reproduction. Types of Asexual Reproduction Include:

24. Cut it half
Binary Fission = simplest form of asexual reproduction. Parent organism divides into two
approximately equal parts. Each daughter cell becomes a new individual.

25. Binary Fission

26. Bacteria Bacteria No organized nucleus.
Genetic material in the form a single circular chromosome.
Before division starts chromosome is replicated then each daughter cell gets one copy of the chromosome.
Can occur every 20-min.

27. Protozoan Protozoa – Mitosis occurs. Cytoplasm
pinches in and divides the organism in half. Each half has a copy of the genetic material. Diagram.

28. Protozoa – Mitosis occurs. Cytoplasm
pinches in and divides the organism in half. Each half has a copy of the genetic material. Diagram.

29. They Where best buds
Budding = Parent organism divides into two unequal parts.
The new organism is created as a smaller out growth or bud on the outside of the parent.
Buds will brake off and live independently or remain attached and form a colony.

30. Budding

31. Yeast – Once the yeast cell reaches a certain size it undergoes mitosis.
Once the genetic material is replicated budding begins.
Hydra – Cells on the outside of the parent hydra begin to undergo mitotic division creating a small group of cells. Those cells continue to divide until in a completely new hydra is formed. Can also reproduce sexually.

32. Yeast cell cycle including budding:

33. Can I have some spore?
Spore Formation – spores = small specialized cells that contain a nucleus and cytoplasm surrounded by a thick outside wall which protects the spore. Under the right conditions the spore can rise to a new organism. Found in bacteria, molds, yeast, mushrooms, mosses, ferns and some protozoans.

34. Spore formation

35. Don’t try this at home
Regeneration = The ability to re-grow lost or damaged body parts. Hydra, planaria, starfish, and earthworm More complex animals less able to re-grow parts. Crab can re-grow a claw. Some reptiles can re-grow a tail. Most mammals can repair damaged tissue but can not re-grow missing parts.

36. Regeneration

37. Vegetative Reproduction

38. Bulb = Short underground stem surrounded by thick leaves
Bulb = Short underground stem surrounded by thick leaves. Contain stored food. As the plant grows it produces new bulbs which will grow into new plants. Tulips, onions, and lilies.

39. Corms = Similar to bulbs but do not contain leaves, just underground stems. Water chestnuts.

40. Tuber = enlarged part of an underground stem that contains stored food
Tuber = enlarged part of an underground stem that contains stored food. Potatoes are tubers. “Eyes” = tiny buds that can form a new potato plant. How you plant potatoes. Great potato famine.

41. Runner or stolen = horizontal stem above the ground with buds
Runner or stolen = horizontal stem above the ground with buds. If a bud touches the ground it will form roots and stems and start a new plant. Strawberries.

42. Rhizome = horizontal stem that grows underground
Rhizome = horizontal stem that grows underground. Thick and contains stored food. Upper portion form nodes which will form buds which will form new plants. Lower portion forms roots. Ferns, cattails, and water lilies.

43. Artificial Vegetative Reproduction

44. Watch out for those old ladies.
Cutting = use a portion of a developed plant to make a new plant. Roses, ivy, and grapevines are reproduced in this way.

45. Layering = a stem is bent so that it is covered with soil
Layering = a stem is bent so that it is covered with soil. Once the branch forms roots it is disconnected from the original plant. Raspberries and roses.

46. Grafting = Bud or stem of one plant is permanently attached to the stem or trunk of a very similar plant. The cambium layers grow together and form a single plant. Apple trees.

47. That’s a strange cacti

48. Why Bother?? Advantages to artificial vegetative propagation:
1. Plants that grow from seed are not always exactly the same as their parents.
2. Takes less time to artificially propagate.
3. Can create seedless fruits.
4. Grafting can be used to generate higher levels of fruit and nut production.

49. Can robot teachers from the future asexual reproduce?
(Relax that was a rhetorical question)

50. Websites Yeast cell cycle including budding:
Mitosis animation: