Mitosis and Cancer You will learn: -Reasons Cells Divide -Phases of the Cell Cycle -Abnormal Cell Growth

Some reasons why cells divide? ________________

Limits to Cell Growth There are two main reasons why cells divide

Reason #1 ______________________________ _____________________________

Understanding DNA Overload In eukaryotic cells, DNA is found in the nucleus of the cell. When a cell is small, the information stored in the DNA is able to meet all the needs of the cell

As the cell increases in size, it usually does not make extra copies of DNA. ___________________________________________________________________________________________________

Reason #2 Food, oxygen, and water enter the cell through its cell membrane. Waste products must leave in the same way. ____________________________________________________________________________________________________________________________________

The rate at which food and oxygen is used up and waste products are produced depends on the cell’s volume If a cell gets too large, ___________________________________________________________________________________________________

What is the Cell Cycle? A period where the cell grows, _______ ___________________________, and divides into two daughter cells.

Interphase (inter = between) The "holding" stage or the stage between two successive cell divisions. ~90 percent of a cell's time in the normal cellular cycle may be spent in interphase.

Interphase (Longest Part of the Cell Cycle) ________________________, but it is included in the cell cycle ___________________________ performing cell functions organelles double in number, to prepare for division

Interphase G1 - (Growth 1) S - (Synthesis) - __________________ G2 - (Growth 2) - cell prepares for division

G1 Phase (Cell Growth) The cell does most of its growing __________________________ New proteins & organelles are synthesized

S Phase (DNA Replication) __________________________________________________________________ _____________________________

G2 Phase (Prep. for Mitosis) Shortest of the 3 phases __________________________________________________________________

M Phase (Mitosis) The process of cell division begins.

MITOSIS ________________________________ __________________________________________________________________

Prophase (pro=primary,first) In prophase, the __________________ condenses into discrete chromosomes. The nuclear envelope breaks down and spindles form at opposite "poles" of the cell.

Prophase Key Events __________________________________________________________________ In animal cells, centrioles begin to migrate to opposite poles _________________________________

What is chromatin? When a cell is "resting" i.e. not dividing, the chromosomes are organized into an entangled structure called chromatin

Metaphase (meta is like middle) In metaphase, the chromosomes are ________________________metaphase plate (a plane that is equally distant from the two _______________________poles). 
The spindles form the framework of the dividing cell.

Anaphase ana=upward,back The centromeres divide and the paired chromosomes __________________________________________________________________________________________

Telophase (telo=end) In this last stage, ____________________________ after the chromatids have migrated to the opposite poles. ____________________________________________________________________________________________

Cytokinesis Cyto =cell Kinesis=movement The cell’s cytoplasm divides at the end of telophase Animals - _________________________ Plants - ___________________________ ___________________________

Results of Mitosis

The Cell Cycle Proteins called cyclins and enzymes that attach to the __________________________________________________________________

What is abnormal cell growth? Also called uncontrolled, rapid cell growth is a central feature of _______________. Virtually every cancer is caused by mutations of DNA _____________________________are most susceptible to mutations, which may lead to ___________________________.

Tumors Tumors are abnormal growth of cells Benign tumors are non cancerous and and only grow locally Malignant tumors are cancerous and spread to other areas of the body

Abnormal Cell Growth

Abnormal Cell Growth

Surgical Removal of Tumor

A Large Abdominal Tumor

Body without Tumor

Cancer Occasionally, cells lose control of the cell cycle This results from: ____________________________ _____________________________ _______________________________________________________________________.

Cancer Cancer is a malignant growth resulting from uncontrolled cell division Malignant =dangerous to health; marked by uncontrolled growth

Cancer Cancer is the second leading cause of death in the U.S. Lung, colon, breast, and prostate cancers are the most prevalent types

Causes of cancer Genetics Environmental Factors ________________________________ Air and water pollution _________________________________ However, there are still unknown causes and researchers are working to discover these factors.

Cancer prevention Healthy Lifestyle Low fat, high fiber diet Exercise Not smoking Taking daily vitamins and minerals Carotenoids, Vitamins A, C, E, and calcium

Cancer Cancer is difficult to treat in later stages because the cancer may have spread to vital organs and damaged them beyond repair.