Question

Multicellular organisms (with more than one cell) cannot just rely on diffusion. Their cells are too far from the external environment, and so they need a transport system with surfaces to molecules.

Answer 1

Step-by-step explanation:

Yes, that is correct. Multicellular organisms, which are composed of many cells, require a specialized transport system to move molecules, such as nutrients, oxygen, and waste products, between cells and the external environment.

Diffusion, which is the movement of particles from an area of high concentration to an area of low concentration, is an efficient way for single-celled organisms to transport molecules. However, for multicellular organisms, the distance between cells and the external environment is often too great for diffusion alone to be effective.

To overcome this challenge, multicellular organisms have evolved complex transport systems, such as the circulatory system in animals or the vascular system in plants. These systems have specialized surfaces, such as blood vessels or plant veins, that transport molecules throughout the organism. This enables cells that are located deep within the organism to receive the necessary nutrients and oxygen, and to remove waste products.