A. <span>Exposure to an antigen
Exposure to viruses and antigens led to the foundation of modern vaccination. Vaccination introduces an antigenic material that helps the ability of the immune system to adapt a specific pathogen, therefore leading to a long-term immunity.</span>
Answer: The organisms are different species, but belong to the same genus.
Explanation: An organism’s scientific name is made up of two parts. The second name is the species name.
Answer:
Plants need water, warmth, nutrients from the soil, and light to continue to grow.
Explanation:
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Actively transport molecules across the cell membrane