What are some of the possible factors associated with aging?
What will be an ideal response?
The changes in immune system, hormone secretion, cellular and molecular changes in the cell, and the effects of free radicals have all been hypothesized to contribute to the aging process. Many developmental changes occur in the body throughout an individual's lifetime. Hormone levels change throughout a person's life; for example, growth hormone concentrations decline with age in both genders, and estrogen declines in females. The rate of cell division slows with age. One hypothesis is that telomeres, which protect the ends of the chromosomes, may influence the number of times cells can divide. Each time the DNA is copied before cell division, a tiny piece of telomere is sliced off. After a certain number of cell divisions, the telomere is gone, leaving the chromosome unprotected. Chromosomes that sustain such damage can no longer participate in cell division. Free radicals are another possible factor; they damage cells and thereby may also contribute to the aging process.
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Imagine that a cell had no motor proteins. Which processes would not be able to occur?
rev: 06_13_2016_QC_CS-53689 _____ Cell division _____ Fertilization of an egg by a sperm cell _____ Protein translation _____ Maintenance of cell rigidity
All vertebrates have an __________ system of secretory glands and cells. Fill in the blank(s) with the appropriate word(s)
three major parts of a cell
What will be an ideal response?
When blood calcium levels are too low, the hormone _____ is released, which stimulates osteoclasts to break down bone and release calcium into the blood
calcitonin growth hormone estrogen parathyroid hormone