What do the signal molecules do to control cell division in normal cells? Growth
ID: 162104 • Letter: W
Question
What do the signal molecules do to control cell division in normal cells? Growth factors a cell to divide, and growth inhibitors prevent division Growth factor a cell to get bigger, and growth inhibitors prevent growth. Growth factors the cell's DNA to growth inhibitors tell DNA to shrink Growth factors keep normal cells from growing too big, and growth inhibitors keep them from staying too small. Tumors can deprive cells of oxygen This happens through which is When tumors block the blood stream, preventing oxygen from getting to some of the cells "downstream" from the blockage When tumors cause blood vessels from the circulatory system to grow into the tumor preventing oxygen and nutrients from travelling to other cells When tumors secrete chemicals that convert oxygen to carbon dioxide, which other cells can't use When tumors in the lungs, blocking oxygen Normal cells in a body communicate, live, divide and eventually die in an organized way to keep body smoothly. In cancer New cells are not produced so damage accumulates as cells age. Cells die much sooner than they should Cell divide uncontrollably and accumulate with severe consequences Cells are unable to repair damage to themselves and so damage accumulates in the body In a normal cell signal, a growth factor kinds to a receptor in the cell membrane, the signal gets relayed molecule to molecule until it gets its message to the transcription factor which regulates gene activity and so regulates the genes controlling cell division. What happens in cancer cells? The cells bypass this normal regulatory pathway and the cells divide out of control. The cells receive too many signals via this pathway and divide out of control. The cells receive signals that trigger mutation and so they divide out of control. The cells bypass the normal regulatory pathway and stop dividing. Mutations in what two types of genes can result in the uncontrolled cell division characteristic of cancer? The Philadelphia Gene and an oncogene An oncogene and a tumor development gene A proto-oncogene and a oncogene A proto-oncogene and a tumor suppressor gene. What is apoptosis? Programmed cell death Cell repair by enzymes Continuous cell division Cancer of a cellExplanation / Answer
15. Growth factors are capable of stimulating cellular growth, proliferation and cellular division. Growth factors serve as signals for the cells to undergo division. Growth inhibitors arrest the cell cycle and stop cell division.
Thus, the answer is a) growth factors tell and cell to divide, and growth inhibitors prevent division.
16. Angiogenesis refers to the development of new blood vessels. Tumors need a dedicated blood stream to provide the oxygen and other nutrients required for its growth. By inducing angiogenesis within the tumor, new blood vessels in the tumor can supply the rapidly dividing cells with the oxygen and other nutrients required. This diverts oxygen rich blood towards the tumor, away from healthy normal cells, thus depriving them of oxygen.
Thus, the answer is b) when tumors cause blood vessels from the circulatory system to grow within the tumor, preventing oxygen and nutrients from travelling to other cells.
17. Cancer in indicated by uncontrolled, unregulated proliferation of cells. These cells lose their function and shape, do not undergo apoptosis, and can even spread to other parts of the body via the circulatory system (metastasis). These uncontrollable cells form lumps called tumors or neoplasms, which can have disastrous effects on the function of other normal, healthy tissue.
Thus, the answer is c) cells divide uncontrollably and accumulate with severe consequences.
18. Cancer cells show uncontrollable growth due to cellular mutations that allow them to bypass the regulatory processes. These cells do not need growth factors for proliferation, and can continue to divide even in the presence of contradictory signals like growth inhibitors or cytokines.
Thus, the answer is a) the cells bypass this normal regulatory pathway and the cells divide out of control,
19. Normal cell division is controlled by proto-oncogenes and tumor suppressor genes. Proto-oncogenes produce molecules that enhance cell division or inhibit cell death. Regulation of proto-oncogenes leads to controlled cell growth. Tumor suppressor genes produce proteins that inhibit cell division and induce cell death. Proto-oncogenes when mutated become oncogenes, which accelerate growth, while mutations in tumor suppressor genes inactivate them, preventing inhibition of cell growth and preventing cell death.
Thus, the answer is d) a proto-oncogene and a tumor suppressor gene.
20. Apoptosis is the process of programmed cell death. Certain signals cause morphological changes in the cell, including blebbing, nuclear fragmentation, chromatin condensation, cell shrinkage, etc, which finally leads to cell death.
Thus, the answer is a) programmed cell death
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.