Answer:
A vaccine works by training the immune system to recognize and combat pathogens, either viruses or bacteria. To do this, certain molecules from the pathogen must be introduced into the body to trigger an immune response. These molecules are called antigens, and they are present on all viruses and bacteria
Explanation:
Is it first?
Explanation:
Darwin first major break through was finding natural selection by using the pea pod method and noticing how some were yellow and some were green with different textures.
Answer: Called the meniscus.
Kuppfer's Cell, monocytes, and lymphocytes
