Answer:
There is sugar on the pig's surface that humans don't have.
Explanation:
"This rapid rejection occurs when human antibodies attach to sugar molecules on the surface of the transplanted pig organ's cells."
From it's environment and from traits from other parents.
The answer is protect the body from infection by pathogens
The physical barrier is made of epithelial cells, mostly will be keratinized to increase their sturdiness further. They will impede the pathogen physically by barricading the cells, makes the pathogen could not invade deeper part of the body. Histamine and antibodies should be the role of immune cells, not epithelial.
The correct answer for the question that is being presented above is this one: "<span> d. All of the above." Th</span>e following statements about the dark reactions is true are the following: Dark reactions occur in the thylakoids of chloroplasts; Light energy is <span>converted to chemical energy during the dark reactions; Carbon dioxide is converted to sugar using ATP and NADPH during the dark reactions.</span>