What are the states below? I just did this unit in class, I might be able to help.
Antibodies, also called immunoglobulins, are proteins manufactured by the body that help fight against foreign substances called antigens. When an antigen enters the body, it stimulates the immune system to produce antibodies. (The immune system is the body's natural defense system.) The antibodies attach, or bind, themselves to the antigen and inactivate it.<span>
Read more: <span>http://www.scienceclarified.com/Al-As/Antibody-and-Antigen.html#ixzz4YlY105DD</span></span>
C) a system is a set of parts that function together as a whole
A biological system is a complex network of biologically relevant entities. ... Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system. source: google
Answer: Photosynthesis
Explanation: Photosynthesis removes CO2 from the atmosphere and replaces it with O2. Respiration takes O2 from the atmosphere and replaces it with CO2.