Final answer:
To prevent the pathogen from reaching the coral, various barriers are in place such as the coral's outer layer of skin and antimicrobial substances found in coral mucus.
Step-by-step explanation:
In order to prevent the pathogen from reaching the coral, several barriers are in place. For example, the coral's outer layer of skin, called the epidermis, acts as a physical barrier. Additionally, coral mucus contains antimicrobial substances that can help prevent pathogens from attaching to the coral's surface.