What component protects the nucleus from harmful substances?

The nuclear envelope is a double membrane structure that surrounds and protects the nucleus in a eukaryotic cell. This component plays a crucial role in maintaining the internal environment of the nucleus, safeguarding the genetic material (DNA) from potential harmful substances and external threats. The nuclear envelope contains nuclear pores that regulate the movement of molecules, such as RNA and proteins, in and out of the nucleus, allowing for the controlled exchange of substances. By controlling access, it helps to protect the delicate genetic information inside the nucleus that is vital for cell function and reproduction.

The other components mentioned, such as the cytoplasm, chromatin, and nucleolus, have distinct roles, but they do not serve the primary protective function of isolating and securing the nucleus as effectively as the nuclear envelope does.