Answer:
The correct answer is 2. Usually multiple mutations are required in different genes to cause cancer.
Explanation:
Mutation is the change in the DNA sequence of a cell which plays an important role in causing cancer. Mutation in many different genes allows the cell to grow and multiply in an uncontrollable manner. It also allows the cell to gain the property of metastasis.
Metastasis is the property of malignant tumor cell which allow the mutated cells to invade different tissues and organs and multiply in numbers. This property plays an important role in causing cancer. Therefore several mutations in different genes are required to cause cancer. So the correct answer is 2.
Rule of law means supremacy of the law
These are arteries, which prevent the backflow of blood because the walls have little muscle to pump blood into the capillaries.
Right vertical blood pumping
left vertical blood pumping
False because people don't have to inhale the smoke
