1. Cell Cycle and Cancer

2. Investigation One

3. Organization of Multi-cellular Organisms • Cell- smallest basic unit of life that can replicate independently • Tissues- cells that share a common structure and function are grouped together • Organ- Two or tissues working together • CellTissue Organ System Organism

4. Tissues • Four Types of Tissues • Epithelial: pack tightly and form the lining of many parts of the body • Muscle: contains special cell that contract, because they have long protein fibers that slide past each other • Nerve: contain long cells that can generate electrical signals in the body • Connective: adds support and structure to the body

5. Tissues

6. Organs • Two or more tissues working together to perform a specific set of functions for the organism • Lung, Heart, liver, skin, eye, Stomach, Brain, Intestines etc.

7. Skin • Skin is an organ that contains several types of tissues including • Connective • Epithelial • Nerve • Muscle • It is our largest organ and protects our body from sun, heat, or cold. • Several Layers • Epidermis • Dermis • Subcutaneous

8. Skin Tissue

9. Skin Tissue • Exposure to sun damages cells in the epidermis, causing them to die and slough off. • Thousands of skin cells are lost everyday • Skin is maintained by replacing the cells that are damaged and die through cell division

10. Lungs • Lungs mostly contain epithelial and connective tissue • The lungs allow the exchange of oxygen from the air we breathe to blood so that it can be delivered to other tissues in the body where it is needed for normal cell function • It also allows carbon dioxide waste in the blood that came from the tissues throughout the body to leave the body through exhalation.

11. Lungs • When air enters the body it travels down the trachea (wind pipe) and into the bronchioles • The air is then lead to the alveoli ducts towards the pulmonary alveoli; which are air sacs where the oxygen in the air is absorbed. • Alveoli balloon like structures that are made up of epithelial cells • The epithelial cells are surrounded by tiny blood vessels called capillaries • The single layer and tiny blood cells allow for the oxygen to travel a short distance

12. Lung Tissue

13. Lung Tissue • Alveoli is surrounded by a single layer of cells • If the alveoli was surrounded by several layers thick, the oxygen from the air and carbon dioxide from the blood would have to travel further making it more difficult to breathe properly, Altering the function of the lungs

14. Breast Tissue • Breast is made of a combination of fatty glandular and connective tissue • These tissues function to supply milk for growing infants • The glandular tissue contains lobes that store milk and ducts for transfer • Breast tissues can be either inactive or active. • Tissue becomes active 3-5 days after a woman gives birth

15. Breast Tissue

16. Breast Tissue • To Transform inactive to active tissue requires a large increase in the number of cells within the lobes and ducts • The extra cells needed to make the larger lobes and ducts are produced through cell division of the existing cells in these tissues

17. Organization of Cells and Organ Function • Cells are organized into tissues and each tissue provides a function that contributes to the function of the organ • Skin- dermis serves to contain connective tissue and blood vessels needed to maintain the epidermis while the subcutaneous has fat cells to keep us warm • Lung- the layer of alveoli cells allows the lung to function by permitting easy oxygen and carbon dioxide exchange • Breast- organization of glandular tissue cells to form lobes and ducts to store and transport milk

18. Replacing Dead Cells in Tissues • Cells replenish themselves through cell division

19. Investigation two

20. Cell Division • Cells within the body are produced from other cells • The original (parent) cell copies all of it contents, including DNA and organelles, and splits these materials evenly into two new daughter cells. • This way the cell has made an exact copy of itself.

21. Cell Division • During childhood the human body grows at a very fast rate • Once an adult human is fully grown, most cells either stop or slow down this process of dividing.

22. Cell Division Phases • Interphase • G1 or GAP phase • S or DNA synthesis phase • G2 or GAP2 phase • M or Mitosis phase • Prophase • Metaphase • Anaphase • Telophase • Cytokinesis

24. Interphase • G1 or GAP phase • Cell produces proteins and grows in size • S or DNA synthesis phase • DNA replication occurs; cell will make an exact copy of the DNA • At the end of S phase each chromosome inside the nucleus of the cell consists of 2 identical sister chromatids • G2 or GAP2 phase • Not much activity occurs

25. Mitosis • Prophase • Chromosomes condense • Metaphase • Duplicated chromosomes line up on spindle fibers • Anaphase • Which sister chromatids separate and move down the spindle fibers to opposite ends of the cell • Telophase • Spindle fibers disappear and new nuclear membranes form around each set of chromosomes • Cytokinesis • Cytoplasm splits in half and cell division occurs

28. Cell Cycle • The process of the cell cycle is regulated by different proteins • The time it takes for a cell to complete the cycle depends on which regulatory proteins are present in that cell

29. Investigation three

30. Regulation of the Cell Cycle • If cells divide at random, the organization of the tissue would be lost and the function of the organ would be affected • If the gene that codes for the controlling protein is damaged or mutated, then a properly functioning protein cannot be produced. • If there is no production of the controlling proteins, the cells will go through the cell cycle and divide unregulated

31. Unregulated Cell Division • If cells divide unregulated each new daughter cell will inherit the mutated gene for this controlling protein because the cell receives an exact copy of DNA in the original parent cell • This means that every daughter cell produced from the originally damaged cell will also divide continuously

32. Cancer • A group of diseases that involve the uncontrolled cell division of the body cells • Cancer begins when one normal body cell breaks free from normal controls of the cell cycle and begins to follow its own rate of cell division. • This process allows a tumor to form

33. Spreading of Cancer • If a single cancerous cell breaks away from the tumor it can travel in the blood to other places throughout the body • Metastases- at the new site this single cancer cell will proliferate and form another tumor

34. Control of Cell Cycle and Cancer • Normally the cell cycle is regulated so that cell only progress through the cycle and divide when necessary • In cancer, the regulation of the cell cycle is lost and the cell divides constantly • The constant cell proliferation leads to a tumor and cancer