3. Staying Alive What does a living thing need to do to stay alive? Use e Store m Take m from the e Remove w Move s R

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1 1. What does cell theory say? Cells are the basic unit of structure and function in living things Every living thing is made of cells all cells come from other cells 2. Cell Organization Prokaryotic Do not have / Do not have Organisms are always & Eukaryotic Have / Have Organisms can be celled or,, & 3. Staying Alive What does a living thing need to do to stay alive? Use e Store m Take m from the e Remove w Move s R Cells divide for: 1) R 2) R 3) G 1. Reproduction Cells divide to create new Asexual Reproduction Offspring is genetically i to parent, only one parent is needed If the parent is a cell, it splits into two, producing two cells o Ex. bacteria ( ) If the parent is, a piece can break off, and grow into another, separate organism o Ex.. blackworms ( ) In certain species of snakes, birds, and sharks, females can produce live young without the need of a male, through a process called All the cells in your body divide in two, to produce more cells. This is a form of asexual reproduction called. The daughter cells are, and must be, to the parent cell. Diagram: 1 of 6

2 Sexual Reproduction Offspring is genetically from parents, two parents are required Parents create, which are cells that have the number of Two gametes come together, forming a cell ( ) with the set of chromosomes The zygote. Every cell of the organism comes from the zygote When the zygote divides, each new cell is to the zygote Diagram: 2. Repair Cells divide to other cells Cells continually wear out, and need to be Cells divide to make up for cells that have died Cell division is what causes, putting new cells back in place of the damaged cells 3. Growth An organism starts as a cell. The cells divide, making the organism grow. But why can t cells just get bigger? Why must cells divide? Some definitions will help you to understand this part: Definitions i) Solute The thing that gets ex. Koolaid is a solute, it gets ii) Solvent iii) Concentration iv) Diffusion The thing the solute gets dissolved in ex. Water is a, the Koolaid gets dissolved in water How much is in a The more of a substance that is dissolved, the the concentration ex. Sweet, gooey Koolaid is more concentrated than watered down Koolaid, because there is more powder (solute) in the water (solvent) When chemicals and nutrients flow from an area of concentration to an area of concentration This is how chemicals travel across the of a cell, and how they travel within the cell ex. when somebody sprays Axe in the hall, and soon it smells like Axe everywhere v) Osmosis When water moves across a membrane to a high concentration 2 of 6

3 Why organisms grow by having cells divide: Chemicals for cell activity and growth travel across the cell membrane by Within the cell, chemicals move by, from areas of high concentration to areas of low concentration Water moves into the cell by, and waste moves out by Osmosis and diffusion are very. If a cell is too big, there won t be enough time for the chemicals to get to where they are needed, and wastes may not be removed in time. Damage to the cell can occur from the presence of and lack of to certain areas. If cells stay, all the chemicals will get to where they are needed in time The three stages of a cell s life: i, m, c Cell Division Overview: Interphase is the resting stage between divisions Cell Division involves: o Mitosis: Splitting of the n (eukaryotic cells only) o Cytokinesis: Division of c, o, cell membrane Animal Cell Division in Detail Remember IPMATC : Interphase, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis 1) Interphase Usually l stage in long, thin, invisible strands Cell carries out life activities ex. growth, making e The DNA d as the cell prepares for division More o made C form 2) Prophase DNA condense into c Nuclear m dissolves Each chromosome consists of two identical strands called sister c, held together by a c. C move apart 3) Metaphase Centrioles send out s f, that attach to chromosomes and move them to the middle of the cell Chromosomes line up in m of cell 4) Anaphase Chromosomes pulled by spindle fibers to o parts of the cell 5) Telophase D) Chromosomes stretch out, become t, and are no longer v New nuclear membrane forms around each group of d c Cell appears to have two n 6) Cytokinesis Cytoplasm divides producing two genetically i daughter cells. Cell membrane is p off in the centre (kind of like dough) 3 of 6

4 1) Checkpoints in the Cell Cycle A signal is sent to the n, preventing the cell from d, if any of the following happen: signals from surrounding c tell the cell not to divide o there is not enough n to provide for cell growth o the DNA within the nucleus has not been r o the DNA is d What happens if the cell loses the signal to stop dividing? 2) Cancer Definitions Cancer Tumor Benign Tumor Malignant tumor Metastasis 3) Features and Causes of Cancer DNA tells the cell what to do A change in DNA is called a A m is something that causes a mutation and changes DNA Not all mutations are bad. Mutations have led to the development of opposable thumbs and a fourchambered heart. However, some mutations can be negative C are a special type of mutagen that can lead to cancer A carcinogen mutates the part of the DNA controlling how the cell divides, leading to un cell d There are many types of carcinogens: o T s Causes /10 cases of lung cancer Can cause mouth, throat, esophageal, bladder, stomach, liver and kidney cancer o R (UV rays in sunlight can lead to skin cancer, x-rays) o V (human papillomavirus can lead to cervical cancer, hepatitis B can lead to liver cancer) o C in p (BPA linked to testicular cancer) o G (breast & colon cancer linked to genetic predisposition) National institutes of health, ID of 6

5 4) Cancer Screening Checking for cancer even if there are no s Important if there is a f h o B & c cancer, retinoblastoma Can find cancer in early stages, and make it easier to treat Examples: o B self-examinations (not as effective as once thought) o T self-examination o PSA blood test, screens for p cancer in men over 50 o Blood tests for c c o Skin checks for m ABCD (Asymmetry, Border, Color, Diameter) 5) Cancer Treatments Surgery o For a and well-defined tumors o For cancers contained in an area that can be removed o Ex. Removing the entire colon because of colon cancer Chemotherapy (pain, pus and poison) o Using c substances to treat a cancer, often c o Target rapidly d cells, not just cancer cells o Travels through body via bloodstream, reaching multiple cancer sites o May shrink t for later surgical removal o Side effects: lower production of b cells, i of digestive tract, h loss Radiation o Damages DNA in cells, preventing c d o Can damage h cells, so precautionary measures are taken: o Using f b to avoid healthy tissue o Implanting a radioactive source into the t o May cause cancer in /1000 cases, - years after exposure. So why use it? 1) Cell Specialization All cells have same, but are not all alike. Multicellular organism: Collection of different types of cells doing specialized jobs. Cells develop in different ways to perform particular functions 2) Stem Cell An cell Become specialized cells when exposed to proper Every cell in your body was originally a Can remain unspecialized and actively for long periods. Controversial Need to embryo to collect a large amount of cell 5 of 6

6 3) Embryonic Stem Cells found in can become any cell type of the body & perform any function Cells: Can form any cell, incl. body & placenta cells Cells: Can form any cells of the body 4) Adult (Tissue) Stem Cells ie. cells Exist in already Differentiate into amount of tissues Ex. stem cells in & can become various blood cells used in treatment of o Original stem cells in bone marrow are cancerous, producing nonfunctional white blood cells o Original bone marrow must be removed with o Replaced with stem cells from a matched o cord blood can be for later use 6 of 6