Question

cytoskeleton
vesicle
rough er
cytoplasm
nuclear envelope
centrioles (in centrosome)
nucleolus
chromatin
lysosome

Explanation:

Identify the target blank in the diagram

Using the Animal Cell Anatomy and Organelle Identification knowledge points, we analyze the pointer lines. The empty box in the upper right points directly to the double-membrane structure surrounding the nucleus, which is the nuclear envelope (or nuclear membrane).

Analyze the structure of the nuclear envelope

The nuclear envelope is a highly regulated double-membrane barrier separating the nucleoplasm from the cytoplasm. It consists of an outer nuclear membrane, which is continuous with the rough endoplasmic reticulum, and an inner nuclear membrane lined by the nuclear lamina.

Explain the function of nuclear pores

The envelope is perforated by nuclear pore complexes. These specialized protein channels regulate the transport of macromolecules, such as RNA and proteins, between the nucleus and the cytoplasm while allowing free diffusion of small molecules and ions.

Answer:

The empty label box in the upper right of the diagram points to the nuclear envelope (or nuclear membrane).