What branch of science deals with the structure of organisms and their parts?

Biology is the correct answer because it is the branch of science that deals with the study of living organisms, their structure, function, growth, evolution, and distribution. Histology is a branch of biology that involves the study of the microscopic anatomy of cells and tissues. Anatomy is the branch of biology that deals with the structure of organisms and their parts, while physiology focuses on the functions and processes of living organisms.