The is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell. 1. plasma membrane 2. nucleoid region 3. ribosome 4. pili 5. cell wall

1. plasma membrane

The plasma membrane is selectively permeable.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

answer; /// i believe the correct answer is (reactants);