In some organisms such as certain fungi and algae, cells undergo mitosis repeatedly without subsequently undergoing cytokinesis. What would be the consequence of this?

The consequence of this "large cells containing many nuclei".

Explanation:

An eukaryotes like fungi contains a complex cellular network. It has a membrane-bounded nucleus where the histone proteins are bundled around the DNA. A few groups of fungi have similar structures to bacterial plasmids.

With just one nucleus, fungi devote much of their lifetime. The cells at the point of the filaments combine when two lonely filaments reach each other and form new frameworks that have two nuclei per cell. This cell with two nuclei takes on its own life and breaks up several times to form a mushroom.