What is the function of gills and lungs in aquatic animals

Basically, gills filter the water around the animal and take in the small amount of oxegen mixed in the water. Lungs take in all of the air and almost half of it is oxgen and they can't go underwater for long. But since lungs are more efficient, animals with lungs can grow bigger than animals with gills

Explanation:

Gills are evaginations of the body surface. Some open directly to the environment; others, as in fishes, are enclosed in a cavity. In contrast, lungs represent invaginations of the body surface. Many invertebrates use gills as a major means of gas exchange; a few, such as the pulmonate land snail, use lungs.

Explanation:

They're just their to help the fish breath

carbohydrates: (starches and sugars) composed of carbon, hydrogen, and oxygen.

lipids: (fats, oils, and waxes) are made of carbon and hydrogen atoms.

nucleic acids: contain hydrogen, oxygen, nitrogen, carbon, and phosphorus. they are polymers of nucleotides. a nucleotide has three parts, a 5-carbon sugar, a phosphate     (-po⬇️4) group, and a nitrogenous base.

proteins: made up of nitrogen, carbon, hydrogen, and oxygen. they are polymers of amino acids.