What is the difference between mutation and adaptation?

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

One function of the immune system is to attack the foreign cells to protect the body. in organ translate , the body recongnizes that the new organ is made of foreign cells. wha kind of medicine would you give a patient to increase the chances of transplate success

Analyze how the water cycle affects a food web. now list 3 examples for each below using complete sentences, on how too much water would affect the same web? how about to little water?