photo by gordon t. taylor, courtesy of the noaa\nwhich level of organization is seen in both arachnoidiscus…

Brief Explanations:

Arachnoidiscus ehrenbergi is a species of diatom, which are unicellular organisms. This means their entire structure and function are contained within a single cell. Therefore, they exist at the cellular level of organization. The human stomach is an organ, which is a complex structure made up of different types of tissues. Tissues, in turn, are composed of groups of similar cells working together. Thus, the human stomach is composed of cells, organized into tissues, which form the organ. The question asks for the level of organization seen in both Arachnoidiscus ehrenbergi and the human stomach. Since Arachnoidiscus ehrenbergi is a single cell, and the human stomach is made of many cells, the common level of organization is the cell. Arachnoidiscus ehrenbergi does not have tissues, organs, or organ systems.

Answer:

cell