One function of the immune system is to attack the foreign cells to protect the body. In organ transplants, how does the immune system take the new organs?

it depends

Explanation:

it it would depend on the blood type or ABO compatibility and if it was the wrong blood type do it attack each other and the person would get sick. but if the blood type matches there is another reason that it may or may not take. that would be called the major histocompatibility complex or MHC. this is basically proteins called cell surface proteins. these proteins are basically the body's way of classifying cells that are of self or non-self. the t cells from an adaptive immune system will look at the MHC and determine whether or not it's for if it's foreign it kills it. if the cell "looks like it belongs ( has compatible blood type and MHC ) then it accepts the transfer.