Causes and Effects of Cancer
Article Review: Cancer
1. Gibbs, W W. "Untangling the Roots of Cancer." Scientific American July 2003: 56-65. Print.
2. In the human body, cells are constantly going through the cell cycle. An important step of the cell cycle is called mitosis, in which the cell (referred to as the parent cell) undergoes a series of steps that lead to the formation of two daughter cells. This process only occurs in somatic cells, which are any non-gamete cells. Gametes are haploid (containing only half of a full chromosome set, 23 chromosomes vs. a diploid’s 46) cells in the form of sperm (males) or ovum (females). Some areas of the body undergo very little mitotic division at all, such as muscles and nervous tissue. Other areas undergo mitotic division in response to a growth factor, which is a signal to cells of a specific area to begin mitosis. This growth factor is released into the extracellular fluid in certain portions of the body in response to four basic stimuli: growth, repair, asexual reproduction, and regeneration. In humans, growth and repair are the prevalent stimuli. Growth dictates the maturation of an organism during a specific period of time—known as puberty in humans. Repair, on the other hand, occurs when an organism sustains an injury such as a laceration, in which mitotic division occurs to create a blood clot to seal the wound, and epithelial cells undergo the process as well to recreate the skin cells that were destroyed. To control the rate of mitotic cell division, the body uses growth signals and antigrowth signals. Cancerous cells are those that ignore antigrowth signals, and can continue to replicate without growth factors. After a certain amount of mitotic divisions, the telomeres in cells shorten until there is none, and programmed apoptosis—cell death—occurs. Cancer cells elongate their telomeres, and so can also replicate almost indefinitely. When these cells start to build up, they form a mass called a tumor. Tumors can either be benign or
1. Gibbs, W W. "Untangling the Roots of Cancer." Scientific American July 2003: 56-65. Print.
2. In the human body, cells are constantly going through the cell cycle. An important step of the cell cycle is called mitosis, in which the cell (referred to as the parent cell) undergoes a series of steps that lead to the formation of two daughter cells. This process only occurs in somatic cells, which are any non-gamete cells. Gametes are haploid (containing only half of a full chromosome set, 23 chromosomes vs. a diploid’s 46) cells in the form of sperm (males) or ovum (females). Some areas of the body undergo very little mitotic division at all, such as muscles and nervous tissue. Other areas undergo mitotic division in response to a growth factor, which is a signal to cells of a specific area to begin mitosis. This growth factor is released into the extracellular fluid in certain portions of the body in response to four basic stimuli: growth, repair, asexual reproduction, and regeneration. In humans, growth and repair are the prevalent stimuli. Growth dictates the maturation of an organism during a specific period of time—known as puberty in humans. Repair, on the other hand, occurs when an organism sustains an injury such as a laceration, in which mitotic division occurs to create a blood clot to seal the wound, and epithelial cells undergo the process as well to recreate the skin cells that were destroyed. To control the rate of mitotic cell division, the body uses growth signals and antigrowth signals. Cancerous cells are those that ignore antigrowth signals, and can continue to replicate without growth factors. After a certain amount of mitotic divisions, the telomeres in cells shorten until there is none, and programmed apoptosis—cell death—occurs. Cancer cells elongate their telomeres, and so can also replicate almost indefinitely. When these cells start to build up, they form a mass called a tumor. Tumors can either be benign or