Vaccination is a process of injecting a dead or weakened form of a pathogen into the body. How does this help strengthen the immune system?

Explanation:

the immune system gets to see how the weakened disease reacts and what are its strengths.

C. It allows the body to keep pathogen information for future infections.

Explanation:

A vaccine helps develop anti bodies inside the immune system to fight off future infections or diseases

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c