What is the dense active protoplasm found in the center of a cell called?

The dense active protoplasm found in the center of a cell is known as the nucleus. The nucleus serves as the control center of the cell, housing the cell's genetic material (DNA) and coordinating its activities, including growth, metabolism, and reproduction. It is responsible for essential functions such as gene expression and regulation, which are crucial for the proper functioning and development of the cell.

The nucleus is surrounded by a nuclear envelope that separates its contents from the cytoplasm, and within this envelope, the dense protoplasm is concentrated. This protoplasm is rich in proteins and nucleic acids, facilitating the processes of RNA synthesis and ribosome production, which are vital for cellular activities. Understanding the role of the nucleus helps in grasping how cells operate and how they respond to their environment.

In contrast, cytoplasm refers to the jelly-like substance outside the nucleus, providing a medium for chemical reactions and supporting the cell's organelles. Ribosomes are the molecular machines that synthesize proteins, not the dense protoplasm itself. Nucleoplasm is the fluid within the nucleus, but the active components that drive its functions are concentrated within the nuclear material.