NN+Reading+Notes

3.1 Questions

 * 1) What does the cell theory state? **The Cell Theory states that "a cell is the basic unit of life." This statement means that as long as there is a cell, the thing is living, even unicellular organisms. Everything living is made up of cells. A second condition is part of the theory as well, it says, "new cells arise only from preexisting cells." This statement means that a living being can't come out of thin air, the parents have to mate, and create a new cellular, living organism.**
 * 2) Why are cells so tiny? **Cells are so tiny so that they can have a better surface area to volume ratio. The greater the ratio, the easier it is for nutrients and wastes to be exchanged. As a cell grows larger, the ratio decreases, so when the cell gets to a certain size, it divides to maintain its ratio and to have a healthy exchange of nutrients and wastes.**
 * 3) How do the light microscopes and electron microscopes differ from one another**? Light and electron microscopes differ in many ways. The first is that the electron microscopes can magnify item much larger, and in higher resolution than the light microscope can. The second difference is that electron microscopes cannot view living organisms, but the light microscope can. The final difference is in how they are operated. The light microscope uses light and lenses to magnify and view the specimen. However, the electron microscopes require vacuums and analyze beams of electrons to receive thei**r **images.**

6.3 Questions

 * 1) What are the different types of white blood cells? **White blood cells are divided into two groups: granular and agranular leukocytes. Granular leukocytes include neutrophils, eosinophils, and basophils. Agranular leukocytes include lymphocytes, and monocytes.**
 * 2) What is the structure and function of each type of white blood cell? **Neutrophils have a multilobed nucleus, and they are the most abundant of the granular leukocytes. They are usually the first responders to a pathogen or bacterial invasion. The next type of white blood cell is the eosinophil. The eosinophil has a bilobed nucleus, and they mainly respond to infections of parasitic worms or during an allergic reaction. The third type of white blood cell is the basophil, and the nucleus of this cell is either U-shaped or lobed, and the cell is found in the connective tissues. This type of cell releases histamine during an allergic reaction. The first type of agranual leukocyte is the lymphocyte, a cell that is responsible for targeting specific diseases. There are two types of lymphocyte, B-cells and T-cells. The B-cells produce antibodies, and the T-cells target certain diseases and is the cell that AIDS targets. The final type of white blood cell is the monocyte. Monocytes are the largest of the white blood cells, and they help to stimulate other white blood cells. They also share the "vacuum cleaner" function with the neutorphils.**
 * 3) Name and describe three disorders of white blood cells. **Severe combined immunodificiency disease is where the stem cells for white blood cells are missing an important enzyme called adenosine deaminase. There are now two ways to treat this disease, the stem cells can be taken out of the body and injected with the enzyme, then replaced, or the person can be injected with the enzymes repeatedly. Cancer, specifically leukemia, is another disease of the white blood cell. Leukemia is usually a mutation of white blood cells or an immature blood cell dividing. The blood cells multiply out of control and eventually lose their ability to fight infection. A third type of white blood cell disease is infectious mononucleosis, also called "mono." This disease results in fever, sore throat, and swollen lymph glands. The symptoms usually go away after a couple of months, but the disease stays dormant in a persons throat and blood cells for the rest of their lives. When people exchange saliva, the virus can reawaken and infect the other person, creating the nickname, the "kissing disease."**

18.1 Questions

 * 1) What are the three stages of interphase? **The first of the stages is called the G1 stage, and this is the stage where the organelles are copied and the material needed for DNA synthesis is accumulated. The second stage is the S stage. During the S stage the DNA is replicated. The final stage is the G2 stage, which is when the proteins needed for cell division are gathered.**
 * 2) How does interphase prepare a cell for cell division? **Interphase is when the cell continues with its normal activities, but prepares to divide. During this time, every organelle is copied so that there is two of each organelle. Interphase is also when the DNA is copied for the new cell.**