Which barrier of innate immunity first come in contact with pathogen ?A Skin and mucous membrane B Fever     C Interferon D Phagocytes

Break Down the Problem

1. Identify the components of innate immunity listed in the options.
2. Determine which component of innate immunity is the first line of defense against pathogens.

Relevant Concepts

• Innate immunity consists of physical and chemical barriers that provide the first line of defense.
• The skin and mucous membranes act as primary barriers against environmental pathogens.

Analysis and Detail

1. Skin and Mucous Membrane: These form a physical barrier to prevent pathogen entry. They are the first to encounter pathogens.
2. Fever: While it is a response to infection, it does not directly come into contact with pathogens.
3. Interferon: This is a signaling protein that helps in fighting viruses but is activated after the pathogen has entered.
4. Phagocytes: These immune cells act after pathogens have successfully entered the body.

Verify and Summarize

The skin and mucous membranes are the first components that pathogens encounter. They form the initial line of defense against infections.

Final Answer

The correct answer is A) Skin and mucous membrane.