What is the function of the nuclear envelope?

The nuclear envelope plays a critical role in maintaining the integrity and functionality of the nucleus, which is the control center of the cell. Its primary function is to protect the genetic material within the nucleus from damage and to regulate the flow of substances in and out of the nucleus. The nuclear envelope consists of two lipid bilayer membranes that are perforated by nuclear pores. These pores facilitate selective transport, allowing necessary molecules such as RNA and ribosomal proteins to exit the nucleus while also controlling the entry of proteins and other molecules needed for nuclear functions. This regulation is vital for proper cellular processes and gene expression.

In contrast, the functions associated with other options do not describe the role of the nuclear envelope. Energy production occurs primarily in mitochondria, photosynthesis takes place in chloroplasts in plant cells, and protein synthesis is mainly carried out by ribosomes. Therefore, the assertion that the nuclear envelope controls substance exchange and protects the nucleus is correct and aligns with the fundamental understanding of cellular biology.