g) if cells are the basic unit of life, why are tissues, organs, and organ systems required in large multicellular organisms?
Even though cells are the basic unit of life, tissues, organs, and organ systems are required in large multicellular organisms. First of all, tissues are made up of specialized cells which are similar to each other, in order to perform certain functions. Organs are made up of numerous tissues. Organ systems are made up of several organs. Cells cannot perform the functions of these tissues, organs, and organ systems needed for large multicellular organisms, however multiple cells make up tissues, organs, and organ systems which are crucial and necessary for large multicellular organisms to perform life sustaining tasks. Moreover, these specialized cells cannot perform even the basic life sustaining tasks such as finding food, or disposing waste in a large multicellular cell alone, instead they need the assistance of other neighboring cells. This is why the many of the specialized cells combine in large multicellular organisms in order to create tissue, organs, and organ systems. For instance, a human is a large multicellular organism. Humans are made up cells, however cells in the body form tissues like the muscle tissue, organs like the heart, and organ systems like the circulatory system.