Which of the following is a characteristic of adaptive immunity?

• A. It is found only in invertebrates.
• B. Responses are the same whether or not the pathogen has been previously encountered.
• C. Responses are active immediately upon infection.
• D. It is common to all animals.
• E. It has the ability to detect very specific pathogens.

Answer: (E)

Verified step by step guidance

1. Understand that adaptive immunity is a part of the immune system that provides a specific response to pathogens.
2. Recognize that adaptive immunity is characterized by its ability to remember past infections, allowing for a faster and more efficient response upon re-exposure to the same pathogen.
3. Note that adaptive immunity is not found only in invertebrates; it is primarily a feature of vertebrates.
4. Realize that unlike innate immunity, adaptive immunity is not immediate; it takes time to develop a specific response to a new pathogen.
5. Identify that the key characteristic of adaptive immunity is its ability to detect and respond to very specific pathogens, which is achieved through the production of antibodies and the activation of specific immune cells.