Answer:
1.5 billion years ago
Explanation:
Protists are a collection formed up of protozoa, unicellular algae, and fungus forms. We will focus on the being part of this society: the protozoa (proto = first, zoa = beings). Protozoa are the earliest discovered collection of heterotrophic living that utilize and modify complicated meal particles into power. Although protozoans are only made up of a single cell, these organisms control to perform all the necessary responsibilities of life. The protozoa are split into four principal associations: the ciliates, the flagellates, the heliozoans, and the amoebas.
South America, Brazil, Canada, And Hawaii
Hope this helps :)
<span>Basically, the body needs to know what it is defending against. Your body can still (usually) fight off infection, even without an immunization, but it takes longer. Basically, your body creates cells with a receptor for a specific disease. When this cell finds the disease it is programmed for, it will send out signals to the "killer" cells to come and kill it. If your body doesn't have the "seeker" cells, it can't fight off the infection until it does. The opposite end are autoimmune diseases, where your immune system starts attacking itself.
brainlest answer</span>
The answer could possibly be natural selection or survival of the fittest
