I think the answer you are looking for is that the stomach is the fourth level of organization.
Answer:
Rough endoplasmic reticulum differ from smooth endoplasmic reticulum by the presence and absence of ribosomes in their surface.
Explanation:
Rough endoplasmic is named so because RER contain ribosomes at their surface and due to the presence of ribosomes rough endoplasmic reticulum play an importnt role in protein synthesis or translation.
Whereas smooth endoplasmic reticulum does not contain any ribosome in its surface.smooth endoplasmic reticulum helps in the biosynthesis of lipid and steroids along with detoxification of toxic compounds.
Dr. Alvarez is doing research on the subfield of psychology called the behavioral neuroscience. Scientists from the field study the biological foundation of human behavioral characteristics. These scientists are trying to find out what physiological processes and anatomical structures are involved in certain aspects of human behavior.