<span>#1) With reference to the role of oncogenes, explain how the normal controls over the cell cycle can be lost.
Answer: The way that cell cycle can be lost is by going through changes in the activity of cell cycle regulators. Cancer causes different types of mutations. There are two types of cell cycle regulators that can promote the development of cancer:
-Positive Regulators that can be over activated (become oncogenic).
-Negative Regulators (tumor suppressors) which can be inactivated.
I hope it helps, Regards. <span /><span>
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Since it is the hearts job to pump blood throughout the body of the organism, the circulatory system would fail and the entire organism would suffer if the heart cells stopped working properly.
<span>Homeostasis is the ability to maintain a constant internal environment in response to environmental changes</span>
b) some bacteria reduce nitrate ion
