What is the difference between innate and adaptive immunity?
A.
Innate immunity is present at birth while adaptive immunity is acquired after exposure to pathogens.
B.
Innate immunity is specific to particular pathogens while adaptive immunity is nonspecific.
C.
Innate immunity is mediated by antibodies while adaptive immunity is mediated by T cells.
D.
Innate immunity provides long-term protection while adaptive immunity provides only short-term protection.
The Correct Answer and Explanation is:
The correct answer is:
A. Innate immunity is present at birth while adaptive immunity is acquired after exposure to pathogens.
Explanation:
Innate Immunity: Innate immunity represents the body’s first line of defense against pathogens and is present from birth. This type of immunity is non-specific, meaning it does not target specific pathogens but rather responds to a broad range of invaders. Innate immunity includes physical barriers such as skin and mucous membranes, as well as internal defenses like phagocytic cells (e.g., macrophages and neutrophils), natural killer (NK) cells, and various chemical signals such as cytokines and antimicrobial proteins. The responses of innate immunity are immediate and act quickly to prevent the spread of infection. Despite its rapid response, innate immunity does not offer long-lasting protection against pathogens.
Adaptive Immunity: Adaptive immunity, also known as acquired immunity, develops over time as a result of exposure to specific pathogens. It is characterized by its ability to recognize and remember specific pathogens through two main components: B cells and T cells. B cells are responsible for the production of antibodies that specifically target and neutralize pathogens, while T cells play roles in killing infected cells and regulating the immune response. Adaptive immunity is highly specific and provides a tailored response to each pathogen. Once the immune system has been exposed to a particular pathogen, it creates a memory of it, allowing for a quicker and more effective response upon subsequent exposures. This memory aspect of adaptive immunity provides long-term protection and is the basis for the effectiveness of vaccines.
In summary:
- Innate Immunity: Present from birth, non-specific, immediate response, includes physical barriers and general immune cells.
- Adaptive Immunity: Acquired through exposure, specific to pathogens, involves B cells and T cells, and provides long-term protection through immunological memory.