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 is an advantage because they approach their environments from all sides equally.
From top to bottom: Earth, Saturn, Mars, Uranus, Venus, Jupiter
Answer:
<h2>A.controlled cell division </h2>
Explanation:
Thankyou
The best answer would be:
Osteoarthritis
<span>It is when the person experiences too much weight bearing activities, which may cause the wear and tear breakdown of the joints. This worn bone may be a foreign material when identifying the joint erosion.</span>