Welcome back to Biology class! What to expect this semester: 1.You’re grade starts fresh today! 2.Grading policies will be the same as last semester, however late work will only be accepted on the days that grades are posted (each Monday/Tuesday). 3.You still need to keep an organized binder. You should clear out your work from last semester, but keep using your spiral. 4. What we will study: a.The cell cycle (cell division and cancer) b.Genetics and patterns of human inheritance. c.Adaptations and evolution of organisms. d.The classification of organisms.

Ch. 8-3 Cancer and the Cell Life Cycle What we’ll learn: What is the normal life cycle of a human cell? What is cancer and how is it related to cells? What are some causes of cancer in humans?

The “Life Span” of a cell, aka the Cell Cycle The cells in your body have a normal life cycle. As your cells grow and get older, they replace themselves through cell division.

Control of Cell Division Genes and enzymes in your cells control when cells go through division. Some cells divide often: Skin cells (daily) Some cells rarely (if ever) divide: Brain cells

Section 8.3 Summary – pages Cancer: A mistake in the Cell Cycle If a cell continues to rapidly divide and replace itself without stopping, cancer may develop. Cancerous cells can form a mass of cells called a tumor, which can deprive normal cells of nutrients.

Cancer: A mistake in the Cell Cycle In later stages, cancer cells enter the circulatory system and spread throughout the body, a process called metastasis, forming new tumors that disrupt the function of organs, organ systems, and ultimately, the organism.

Environmental factors, such as cigarette smoke, air and water pollution, and exposure to ultraviolet rays from the sun, are all known to damage the genes that control the cell cycle. The Causes of Cancer

Cancer may also be caused by viral infections that damage the genes, or mutations that change the function of DNA and genes. The Causes of Cancer

Section 3 Check Explain cancer in terms of cell growth. Question 1

Section 3 Check Explain cancer in terms of cell growth. Question 1 Answer Cancer is a malignant (harmful) growth resulting from uncontrolled cell division. The loss of control may be caused by environmental factors, like UV radiation, or mutations to DNA and genes.

Problem Solving Lab Get Whale Book and a Calculator. Open to page 212. Answer questions 1-4 on a sheet of paper titled # L-1 Understanding Cancer.

Answer to # 1 The most common type of cancer is Skin: basal cell and squamous. The least common type of cancer is Skin: melanoma

Answer to #2 Least treatable: Lung Most treatable: Skin: basal cell and squamous.

Answer to #3 Percent survival for breast cancer: 180,000 cases – 40,000 deaths = 140,000 survivors 140,000 survivors / 180,000 total cases = 0.78 x 100 = 78%

Answer to #4 Add total number of cancer cases = 1,605,000 Number of lung cancer = 170, ,000 / 1,605,000 =.10 x 100 = 10%