What is the gel-like fluid found outside the nucleus called?

The gel-like fluid found outside the nucleus is known as cytoplasm. This substance fills the interior of the cell, providing a medium in which various organelles are suspended and where many metabolic processes take place. It has a semi-fluid consistency that allows for the movement of materials within the cell and supports the cells' structure.

Other options refer to different components or contexts within cellular biology. Stroma typically refers to the supportive tissue in organs, particularly in the context of chloroplasts in photosynthesis. Cytosol is specifically the liquid portion of the cytoplasm, excluding organelles, while matrix generally refers to the internal compartment of mitochondria or the extracellular matrix that supports tissues. While these terms are related, they describe different aspects of cellular composition, making the cytoplasm the most appropriate choice for the gel-like fluid that surrounds the nucleus.