Final answer:
The combining form 'hist/o' is associated with histology, the study of tissues at the microscopic level.
Step-by-step explanation:
The combining form hist/o refers to histology, which is the study of the shape and arrangement of cells in tissue. Histology plays a crucial role in understanding how tissues are structured and function, as all cells and tissues in the body originate from the three germ layers: ectoderm, mesoderm, and endoderm. These layers develop into the complex systems that constitute the human body, each layer giving rise to different tissues and organs. The role of histology in medical science extends to various fields including histopathology, which is the study of diseased tissue, and is crucial for diagnosing numerous conditions.