I just took the test and the correct answer is B. eukaryotic cells
The answer is Vaccination.
Acquired or adaptive immunity is the body's third line of defense. This is protection against specific types of pathogens. Acquired immunity may be either natural or artificial in nature. Both natural and artificial immunity have passive and active components. Active immunity results from an infection or an immunization, while passive immunity comes from naturally or artificially gaining antibodies.
Antonie van Leeuwenhoek viewed moving objects from pond water under his microscope and named them “animalcules.
Antonie van Leeuwenhoek was a scientist and the first microscopist to observe protozoa and bacteria. He created microscopes that possess a single high-quality lens of small focal length and isolated tiny animalcules (microbes) from various sources such as pond water, well water and rain water. Through his experiments, he also calculated the sizes of the animalcules.
I believe it is the nitrogen base. Adenine pairs with Thymine, and Cytosine pairs with Guanine.
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