Answer:
Exposure to the disease
Explanation:
Before vaccines, the only way to develop immunity to a disease was to be exposed to the disease-causing pathogen without being harmed by it. A good example of this is smallpox, which was also the first vaccine developed. It was noticed that milk maids weren't catching and dying from small pox like everyone else, because they had been exposed to cowpox. This premise was used to create the first vaccine.
Vaccines give you immunity by injecting you with a small amount of a (usually inactive) pathogen. inside your body. This means your immune system produces antibodies against it. Similar to what happened with the milkmaids.
Answer:
2.)how much a certain area can hold is carrying compacity
3>)if a disease killed most of the producers the species would have a chance of dying out
Explanation:
An organic compound<span> is any member of a large class of gaseous, liquid, or solid chemical </span>compounds<span> whose molecules contain carbon. From this, you could be able to find the answer.</span>
