Answer:
D) Expressed in the stomach, but not in the cells of the small intestine
Explanation:
Antigens are proteins that are found on the surface of the pathogen and are viruses, fungi, or bacteria. Nonliving substances such as toxins, chemicals, drugs, and foreign particles. Antigens are usually carried by proteins and polysaccharides, and less frequently, lipids but it also needs to be attached to a large carrier molecule which is usually a protein. When an antigen enters the body, the immune system produces antibodies against it. The Antigen stimulates the immune system to produce antibodies. YOUR WELCOME ;)
Stem cells begin to transfor into different types of cells in the human body in a process known as cell differentiation.
Cellular differentiation occurs throughout the cell development of a multi-cellular organism. It occurs when the cell changes from a simply zygote into a complex system of tissues and cell types.
Stems cells are cells which have the potential to develop into many different cell types in the body during early life and growth. Stem cells serve as internal repair system in many tissues. When stem cells divide while undergoing cell differentiation, it can either retain being a stem cell or become another type of cell like muscle cell, brain cell, or red blood cell.
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