1. The Integumentary System
More Than Skin Deep
Mitosis

2. TAKS
Objective 2 – The student will demonstrate an understanding of living systems and the environment.

3. TEKS
The student knows the structures and functions of nucleic acids in the mechanisms of genetics. The student is expected to
(C) compare the processes of mitosis and meiosis and their significance to sexual and asexual reproduction

4. Engage
Grace’s Story

5. Explore 1: Onion Root Tip
How many anaphases can you spot?
What phase is represented by the cells with the dark circles?

6. Exploration 2: Onion/Whitefish Lab

7. Cells in Action
Mitosis
Mitosis Animation

8. Explain: Mitosis (Nuclear Division)
Mitosis is considered nuclear division since the steps only refer to the contents of the nucleus.
There are 4 steps.
Prophase P
Metaphase M
Anaphase A
Telophase T

9. Prophase

10. Early Metaphase

11. Late Metaphase

12. Anaphase

13. Telophase

14. Interphase Review (G1, S, G2)
Chromosomes are replicated
Chromsomes appear as threadlike coils (chromatin) at the start, but each chromosome and its copy (homologous chromosome) change to sister chromatids at the end of this phase

15. Prophase The nucleus disappears DNA Condenses
The chromatid pairs (sister chromatids) are joined by a centromere.
The thread-like spindle fibers appear.
The centrioles move toward the poles.

16. Metaphase The shortest stage of mitosis.
Sister Chromatids attach to spindle fibers
Chromatid pairs line up along the equator (middle) of the cell.
Why does this occur?
So that each new cell will receive one chromatid from the pair.

17. Anaphase
The chromatid pairs separate and the separated chromosomes move in opposite directions.
The spindle fibers contract and somehow pull them toward the poles.

18. Telophase The cell begins to separate.
Two new nuclei begin to reappear.
Chromosomes decondense to form chromatin
The spindle fibers disappear.

19. Cytokinesis Final separation into 2 new daughter cells.
Cells are identical in the type and number of chromosomes it contains.
Each cell has its own nucleus with identical DNA
If a cell containing 46 chromosomes undergoes mitosis, how many chromosomes does each of its daughter cells contain? 46
Where did the extra 46 chromosomes come from?
The S phase of the cell cycle.

20. Stages of Mitosis
Name Each

21. Anaphase

22. Early Metaphase

23. Prophase

24. Telophase

25. Late Metaphase

26. Questions
What is all body tissue composed of?
What is mitosis?

27. Elaborate
Most common and preventable disease of the integument is skin cancer
Skin cancer - most common form of cancer in the US
Cancer - general term for over 100 diseases our body, including the skin
Cancer - uncontrolled growth of abnormal and damaged cells.
What is skin cancer?

28. Skin Cancer

29. Skin Cancer
One cell is damaged by the sun and is no longer a normal skin cell.
This cell continues to grow uncontrolled and builds up in a location of the body making a tumor.
Malignant tumors can invade and destroy other tissues and spread to other parts of the body through the blood stream and lymphatic system.

30. Lymphatic System Network of Vessels Carries Lymph- Colorless Fluid
Lymph is carried to organs including the lymph nodes, spleen, thymus, and to cells throughout the body.

31. Metastasis
When cancer spreads to other parts of the body this is called metastasis

32. Types of Skin Cancer Basal cell carcinoma Squamous cell carcinoma
Melanoma

33. Basal Cell and Squamous Cell
These are the most common forms of skin cancers
Basal Cell – Most common type
Starts in the basal cells
Slow Growing
If left untreated, invades cartilage and bone causing disfigurement
Squamous cell – Second most common
Starts in the squamous cells
Most common form of skin cancer in those with darker skin
Starts as a nodule or red patch with well-defined outline
May metastasize if left untreated

34. Melanoma Less common than Basal and Squamous cell cancers MOST DEADLY
Starts in melanocytes
Linked to severe sunburns in childhood and adolescence
Caused by short, intense, excessive, exposure to ultraviolet light
Every blistering sunburn you get before you turn 18 increases your chances of developing melanoma

35. Questions What are the three types of skin cancer?
Which types are the most common?
Which skin cancer is most serious? Why
Which cancer is caused by “short, intense, excessive, exposure” to ultraviolet light?
Which is the most common skin cancer in people with darker skin?

36. Treatments Melanoma Basal and Squamous
Surgery is most common, and the only certain cure
Basal and Squamous
Surgery
Freezing
Burning
Scraping
Creams and lotion-based chemotherapy
Radiation