Astudentt observe a fish resting in the classroom fish tank . the fish mouth was openning and closing regulary as it pumped water over its gills . why was the fish pumping water over its gills ?

a

you got this this :)

the answer is b.) hydrogen bonds between bases.

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.