AP BIOLOGY

Detailed explanation-1: -A reason is that multicellular organisms need special organs for exchange of gases with the environment because of prokaryotic cells found in the body. The cells are not in contact with the environmentand therefore diffusion would not work in the exchange of gases.

Detailed explanation-2: -In multicellular organisms cells differentiate and specialize to form tissues which cooperate to form organs such as brains, kidneys, hearts, stomachs, and lungs. Without specialized cells multicellular organisms would be nothing more than a homogeneous lump of cells.

Detailed explanation-3: -The multicellular organisms remove excretory products by the process of simple diffusion.

Detailed explanation-4: -Characteristics of Multicellular Organisms They possess distinct organs and organ systems. They are eukaryotes, i.e., they contain membrane-bound structures. Their cells exhibit division of labour. Their size increases with the number of cells in an organism.