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 = B
If you look at A, it obviously is not right. And C doesn’t make sense either
All cells have cell membranes, and the membranes are flexible. So animal cells can have various shapes, but plant cells only have the shapes of their cell walls. That's nice for plants, because it gives them the ability to grow up and out, where they can get lots of sunlight for making their food.
The typical use for nonrenewable resources is by burning fossil fuels, use them for transportation, heat our food and produce electricity.
Answer:
Animals are dependent for multiple reasons.
Explanation:
The energy is transferred to animals when they eat plants. They also need it because vitamin D is given when animals get sunlight on their bodies, building strong bones and healthy marrow. The same happens when they eat vitamin D-rich plants. Hope this is helpful!
