Which example involves a cell membrane receiving and sending messages? a. the cell membrane prevents glucose from entering a cell. b. a transport protein allows a large molecule to enter a cell. c. cells of an organism tell each other when predators are near. d. an enzyme acts as a catalyst for a reaction on a cell membrane.

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.

explanation:

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.