Question

Suppose we obtain clinical samples from three muscle biopsies, one from a muscle that has undergone hypertrophy, a second from a muscle that shows signs of hyperplasia, and a third that is from a normal muscle. If we extract DNA from 100 mg of each biopsy, would we expect the same or different amounts of DNA from each sample? Explain your reasoning carefully and thoroughly.

Answer 1

Hypertrophy is the increase in tissue volume due to increased cell size. Any cell that has undergone hypertrophy contains larger amount of DNA than the normal cell. The muscle cells do not divide, but they can enlarge. When we do excercise and take nutritious food, the cells make maximum effort that results in duplication of DNA and enlargement of other cellular components, but the cell actually do not divide.

Hyperplasia is the increase in tissue size due to increased rate of cellular reproduction. But, muscle cells and nerve cells do not undergo cell division. However, in the given case, it is said that the second sample is taken from a cell that is showing the signs of hyperplasia, means a newly formed muscle cell. Non-reproductive cells generally contains larger DNA than reproductive cells, because after every cell division, the DNA undergoes erosion at its ends.Thus, it is expected to have a smaller size DNA than an adult normal muscle cell DNA content.

Thus, the DNA contetn in all the three samples varies from one another.