Which body system produces proteins that fight infections?

Answer and Explanation:

The Immune System. It comprises the white blood cells, lymphatic system, etc. The immune response is the production of antibodies in response to antigens present in pathogens and other foreign matter.

The leukocytes are formed in the bone marrow of long bones and lymph nodes. Their function is to protect the body from invasion of foreign material like bacteria and viruses( pathogens). They help fight against infections by engulfing and digesting pathogens and production of antibodies which are proteins that bind to pathogens. Their number increases greatly during infections.

yes, because even though a theory has a  lot of evidence to support it, it is not always true

well first you need the sample of the temperature and gas level. i couldnt write a hypothesis unless i had some data. i think temperature changes will effect volumes of gas because gas changed into a solid or liquid at specific temperatures.