Chapter 10 questions

Section 1

1. Two reasons why cells divide are one the larger they become the more stress it puts on the DNA. Also the the bigger it becomes the harder it is for it to move nutrients and waste across the membrane.



2. The cells DNA is like a library because the larger the cell becomes the more stress it puts on the DNA, in comparison the larger a town gets the more people that want to check out books and the more stress it puts on the library.



3. The solution to the problems with cell growth is cell division.



4. As the cell increases in size the volume increases faster then the surface area.



5. For a cell that has a length of 4cm its surface area would be 96 and its volume would be 64.

Section 2

1. The main events in the cell cycle are: Prophase, Metaphase, Anaphase, and Telophase.

2. In Prophase the chromatin condense into chromosomes and centrioles splilt and form spindle fibers. Metaphase the chromosomes line up across the center of the cell. Each chromosome is connected to a spindle fiber at it centromere. Anaphase the sister chromatids separate into individual chromosomes and are moved apart. Telophase the chromosomes gather at opposite ends of the cell and lose their distinct shapes. Two new nuclear membranes form.

3.During interphase the cell grows and replicates its DNA.

4.Chromosomes are made up of chromatin and a centromere.

5.Prokayotic cells divide by just spliting DNA and the cell.

6.Cytokinesis is simlar in plant cells and and animal cells in that the parts replicate before the cell can divide. A major difference is that in a plant cell a cell plate forms between the two membrans.

Section 3

1. Cyclin regulates when a cell will divide.

2. Cancer cells do not resond to the signals that regulate the dividing of cells. So they replicate out of control.

3. When cells come into contact with other cells, cell division slows.

4. Cancer is considered a disease because it messes up cell division and cause out of control cell division.

5.If cyclin was injected into a cell in the process of mitosis it would speed up because it is a stimulate.

Section 4

1. D. surface area

2. C. two daughter cells

3. A. centriole

4. C. 12

5. C. chromatids

6. A. prophase

8. B. cyclins

9. A. speeds up/slows down the cycle

10. A. cancer

Cell Vocab

cell division-the process by which cells multiply involving both nuclear and cytoplasmic division

chromatid-one of the usually paired and parallel strands of a duplicated chromosome joined by a single centromere

centromere-the point or region on a chromosome to which the spindle attaches during mitosis and meiosis

interphase-the interval between the end of one mitotic or meiotic division and the beginning of another

cell cycle-the complete series of events from one cell division to the next

mitosis-process that takes place in the nucleus of a dividing cell, involves typically a series of steps consisting of prophase, metaphase, anaphase, and telophase, and results in the formation of two new nuclei each having the same number of chromosomes as the parent nucleus

prophase-the initial stage of mitosis and of the mitotic division of meiosis characterized by the condensation of chromosomes consisting of two chromatids, disappearance of the nucleolus and nuclear membrane, and formation of mitotic spindle

centriole-one of a pair of cellular organelles that occur especially in animals, are adjacent to the nucleus, function in the formation of the spindle apparatus during cell division, and consist of a cylinder with nine microtubules arranged peripherally in a circle

spindle-a spindle-shaped network of chiefly microtubular fibers along which the chromosomes are distributed during mitosis and meiosis

metaphase-the stage of mitosis and meiosis in which the chromosomes become arranged in the equatorial plane of the spindle

anaphase-the stage of mitosis and meiosis in which the chromosomes move toward the poles of the spindle

telophase-the final stage of mitosis and of the second division of meiosis in which the spindle disappears and the nuclear envelope reforms around each set of chromosomes

cytokinesis-the cytoplasmic changes accompanying mitosis

cyclin-any of a group of proteins active in controlling the cell cycle and in initiating DNA synthesis

cancer-a malignant tumor of potentially unlimited growth that expands locally by invasion and systemically by metastasis

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