In the Section "Investigating Life: Does Natural Selection Maintain Cystic

Multiple Choice

In the section "Investigating Life: Does Natural Selection Maintain Cystic Fibrosis?",CFTR moves chloride ions out of cells by active transport.What can be inferred from this statement when the CFTR is functioning?

A) Chloride concentrations become higher on the outside of the cell.
B) Chloride concentrations become higher on the inside of the cell.
C) Sodium concentrations become higher on the outside of the cell.
D) Sodium concentrations become higher on the inside of the cell.
E) Water crosses membranes by active transport.