How can mass help identify an unknown substance

Which of these is not a function of some membrane proteins ? a. allowing polar molecules to enter the cell b. recognizing other types of cells c. receiving messeges from other cells b. carrying messages to oher cells

Which of the following is an example of this type of co-evolution

If two parents who's blood types are both b produce a child that has blood type o, what can you say about the parent's genotybes? oa) one is ii ob) one is ibi oc) both are bi od) nothing, this is impossible