I think it's called infectious agent or something close to that.
Tolerance is one aspect of physical dependence. It's basically when your body gets used to a medication and you no longer get the same amount of pain relief from a given dose of the medication. A person needs to continue to increase the dose of the medication in order to get the same effect.
Withdrawal is another component of physical dependence. That's when the medication is stopped abruptly or the dose is lowered too quickly and a person experiences unpleasant symptoms
The statement is once a year for women over 40 as they're more likely to develop breast cancer. Also it's once a year for all women over 18 with a family history of breast cancer as it is very rare to develop breast cancer as a child.