DH+cell+homework+1

The cell theory states that there is nothing smaller than a cell that is alive and "a cell is the basic unit of life". All living things are made up of cells, and new cells arise only from preexisting cells. Cells are the size they are because of how much they multiply and divide. They grow big once they have a lot of nutrients, then they divide themselves and become smaller. The light microscope uses "a set of glass lens and light rays passing through the object to magnify objects, and the image can be viewed directly by the human eye." However, the electron microscope "provides a three dimensional view of the surface of an object".
 * HOMEWORK 9/8/07**
 * __3.1__**
 * 1. What does the cell theory state?**
 * 2. Why are cells so tiny?**
 * 3. How do the light microscope and electron microscopes differ from one another?**

__**6.3**__ There are five different types of white blood cells. Neutrophil, eosinophil, basophil, lymphocyte and monocyte are the five different kinds.
 * 1. What are the different types of white blood cells?**
 * 2. What is the structure and function of each type of white blood cell?**
 * Neutrophils "account for 50-75% of all white blood cells; therefore, they are the most abundant of the white blood cells. Neutrophils are usually first responders to bacterial infection, and their intense phagocytic activity is essential to overcoming an invasion by a pathogen." They are thought of as the vacuum cleaners of the body because they "suck up unwanted substances, for example, pathogens."
 * "Eosinophils have a bilobed nucleus, and their large, abundant granules take up eosin and become a red color. Not much is known specifically about the function of eosinophils, but they increase in number in the event of a parasitic worn infection or an allergic reaction."
 * "Basophils have a U-shaped or lobed nucleus. In the connective tissues, basophils, and also similar type cells called mast cells, release histamine associated with allergic reactions."
 * "Lymphocytes account for 25-35% of all white blood cells, and therefore, they are the second most abundant type of white blood cells. Lymphocytes are responsible for specific immunity to particular pathogens and their toxins (poisonous substances)." There are B-cells and T-cells.
 * "Monocytes are the largest of the white blood cells, and after taking up residence in the tissues, the differentiate into even larger macrophagea except in the skin, where the become dendritie cells."
 * 3. Name and describe three disorders of white blood cells.**
 * Severe Combined Immunodeficiency Disease (SCID) is "when the stem cells of white blood cells lack an enzyme called adenosine deaminas. Without this enzyme, the body cannot fight infections of any sort." There are two ways to keep this disease under control. One is to use gene therapy, and the other is to repeatedly give injections of the missing enzyme.
 * Leukemia is a cancer that in which the conditions involve "uncontrolled white blood cell proliferation. Most of these white blood cells are abnormal or immature, therefore, the are incapable of performing their normal defense functions."
 * Infectious mononucleosis is a product of an Epstein-Barr virus. "It is called infectious mononucleosis because lymphocytes are mononuclear. EBV, a member of the herpes virus family, is one of the most common human viruses. Symptoms of infectious mononucleosis are fever, sore throat, and swollen lymph glands."

__**18.1**__ The three stages of interphase are the G1 stage, the S stage, and the G2 stage. Interphase helps prepare a cell for cell division because it preps everything. The first stage is fo
 * 1. What are the three stages of interphase?**
 * 2. How does interphase prepare a cell for cell division?**