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>
It’s cell wall and chloroplast. We don’t need chloroplast because we don’t make our own food.
Answer:
A person standing on the ground is barely affected by surface gravity
Ecosystems disturbed by a nature will be eventually restored unless it's a really big cataclysm, but most of the ecosystems are now a human caused disturbance. For example there are plenty of species which are already extinct or nearly extinct because of hunting industry.
The answer to this question would be :4.) SpeciesIn taxonomy, the organism will be divided into different groups based on a specific character from that organism. It could be an organ
The sequence from top to bottom would be:
<span>life
<span>domain
</span><span>kingdom
</span><span>phylum
</span><span>class
</span><span>order
</span><span>family
</span><span>genus
</span><span>species
The lowest subgroup is called species</span></span>
