Organ culture refers to the cultivation of organs in a laboratory through the synthesis of tissues. In this process, cells or tissues are taken from an organism and grown in a controlled environment outside of the body. This allows scientists to study the behavior and development of organs in a controlled setting, without the need for a whole organism.

Option 1 is incorrect as it refers to the aspects of culture in a community that are related to the needs of a specific organ of the human body. This does not accurately describe organ culture.

Option 2 is incorrect as it refers to the maintenance of a whole organ after removal from the organism by partial immersion in a nutrient fluid. While this is a technique used in organ culture, it does not encompass the entire concept.

Option 3 is incorrect as it refers to the introduction of a new organ in an animal body to create genetic mutations in the progenies of that animal. This is not related to the concept of organ culture.

Therefore, the correct answer is option 4, which accurately describes organ culture as the cultivation of organs in a laboratory through tissue synthesis.