Answer to Question 1
Answer: The key to the body's successful immune system is the ability to distinguish self (or proteins that belong to its body) from non-self (proteins that belong to any other living thing).
Answer to Question 2
Answer: Cytotoxic T cells directly kill virus-infected cells and tumor cells. Helper T cells secrete proteins that promote inflammation by calling for the microphages to the site, stimulating B cells, and activating the cytotoxic T cells. Regulatory T cells help lower the immune response once the infection is under control. Memory T cells remember an antigen and therefore can produce new fighting cells rapidly.
Polaris system
Lymphatic vessels pick up excess tissue fluid, purify it in the lymph nodes, and then return it to t
respiratory system
A depiction of slaves on a South Carolina plantation, around 1790. Likely of Yoruba descent, they pl
The Koeppen System
Please fully explain in detail