3.1+what+is+a+cell?+6.3+white+blood+cells+and+defense+against+disease+18.1+chromosomes+and+cell+cycle-+rebecca

-Organisms, including humans are composed of cells. -cells are quite small and can be seen only under a microscope. - cells are about 100 micromerters in diameter ( the width of a human hair) - a cell is the sacis unit of life. - all living things are made of cells. -humans are mulitcellular. - cells in a mulitcellular organism are specialized in structure and function. - new cells arise only from preexisting cells. - Neutrients enter a cell and waste exits the cell at the surface- therefore the greater the amount of surface teh greater teh ability to get material in adn out of the cell. - cell division restores the amount of surface area needed for adequate exchange of materials.
 * 3.1- what is a cell?**

Questions: - The cell theory states that a cell is the basic unit of life. Nothing smaller tha a cell is alive. All living things are made up of cells. New cells only arise from preexisting cells.
 * 1. What does the cell theory state?**

- Cells are so tiny because we have so many of them. Their surface area allows nutrients ro enter and for waste to exit. The small size of a cell is explained by considering the surface- area- to - volume ration of cells.
 * 2. Why are cells so tiny?**

- A light microscope uses a set of glass lenses and light rays passing through the object to magnify objects, and the image can be viewed directlyby the human eye. The transmission electron microscope makes use of a stream of electrons to porduce magnified images. The human eye can't see the image, and therefore it is projected onto a fluorescent screen or photographic film to produce an image that can be viewed.The magnificationporduced by a transmission electron microscope i smuch higher that that of a light microscope. The electron mircoscope has a higher resolving power of the eye.
 * 3. How do the light microscope and electron microscopes differ from one another?**

Questions: -Each type is regulated by a protein called colony- stimulating factor (CSF). - Eosinophils, basophils, neutrophils, Lymphocytes monocytes. - White bloods cells are classified into the granular leukocy and the agranular leukocytes.
 * 6.3- White blood cells and defense against disease.**
 * 1. What are the different types of white  blood cells?**

- Granular Leukocytes= include neutrophils, eosinoph and basophils. neutrophils account for 70% of all white blood cells. They are also like "vacuum cleaners" because they suck unwanted substances for example, pathogens. Also the eosinophils are granular.The increase in number in the event of a parasitic wound infection or an allergic reaction. Basophils and tehy release histamine. Histamine dilates blood vessels, but constricts the air tubes that lead to the lungs (asma attack).
 * 2. What is the structure and function of each type of white blood cell?**

- Agranular Leukocytes= Lymphocytes and monocytes. Lymphocytes are responsible for specific immunity to particular pathogens and their toxins. There are 2 types of Lymphocytes: B cells and T- cells. Bcells portect us by porducing antibodies that will attack the pathogenes. T- cells directly destroy pathogens. Monocytes are also like vacuum cleaners. They stimulate other white blood cells to defend the body.

- Leukemia=uncontrolled white blood cell proliferation. These cells are abnormal or immature. -SCID= stem cells lack an enzyme called adenosine deaminase.- Your body can't fight infections of any sort. - EBV= the cause of infectious mononucleosis. Lymphocytes are mononuclear. It is apart of the herpes virus family. Fever, sore throat, swollen lympth glands. Stress can reactivate this virus.
 * 3. Name and describe three disorders of white blood cells?**


 * 18.1- Chromosomes and the cell cycle**

**1. What are the three stages of interphase?** -G1 stage, S stage, G2 stage.

-The cell enters the cell devision part of the cell cycle. It goes through mitosis and Cytokinesis. During Mitosis- the nuclear disivion, 2 daughter cells have the chromosomes distributed to their nucli. Cytokinesis- the division of the cytoplams and there are 2 daughter cells.
 * 2. How does interphase prepare a cell for cell division?**