Cells at Work!

In this chapter, we learn that the common cold is caused by inflammation, and that the immune system is responsible for its symptoms. We learn that a cell's own dna is copied during interphase and then divided during mitosis. The duration between cell division marks a single cycle. The number of times cells can divide in their lifetime depends on the type of cell. The cell that is wearing a stylish hat comes to the rescue. He tells the cell that there is an enemy nearby and that he will kill it if it tries to escape. The immune system, he says, is so full of itself that it is violent. He asks the cell if it has a tissue, and the answer is that it does. He then asks if the cell has a regulatory cell that controls its activity. The answer is yes, and he is glad to see that the cell is a representative of the cold.