Chapter 21 - Section 21.3 - Study Guide - Assess Your Learning Outcomes - Page 844: 3

Adaptive immunity can be classified based on whether it is active or passive, as well as whether it is natural or artificial. These classifications determine whether immune memory and lasting protection are developed. Let's explore each category: **Active Immunity:** Active immunity refers to the immune response that is generated within an individual's own immune system as a result of exposure to antigens, usually through infection or vaccination. It involves the activation of immune cells and the production of memory cells. Active immunity results in immune memory and lasting protection. - **Natural Active Immunity:** This occurs when an individual's immune system responds to actual infection with a pathogen. The immune response leads to the development of memory cells, ensuring that if the same pathogen is encountered again, the immune system can mount a rapid and effective response. - **Artificial Active Immunity:** This is achieved through vaccination. Vaccines contain weakened or inactivated forms of pathogens or pieces of antigens. When administered, vaccines stimulate the immune system to generate an immune response without causing the disease. This results in the production of memory cells and provides protection against future infections with the actual pathogen. **Passive Immunity:** Passive immunity involves the transfer of pre-formed antibodies or immune cells from one individual to another. It does not lead to the development of immune memory and lasting protection because the recipient's immune system is not actively involved in the response. - **Natural Passive Immunity:** This occurs when a baby receives antibodies from its mother through the placenta or breast milk. These antibodies provide temporary protection to the baby's immune system until it develops its own active immunity. - **Artificial Passive Immunity:** This involves the direct administration of antibodies produced by another individual or an animal. For example, injection of immune serum or specific antibodies can provide immediate but short-term protection against certain diseases. Since the recipient's immune system is not engaged, there is no development of memory cells or lasting protection. In summary: - Active immunity, both natural and artificial, results in immune memory and lasting protection because it involves the activation of the individual's immune system and the production of memory cells. - Passive immunity, both natural and artificial, does not result in immune memory and lasting protection because it does not involve the individual's immune system actively responding to the antigen. Vaccination, which falls under active artificial immunity, is a crucial method for generating immune memory and conferring long-term protection against infectious diseases without causing the disease itself.

Adaptive immunity can be classified based on whether it is active or passive, as well as whether it is natural or artificial. These classifications determine whether immune memory and lasting protection are developed. Let's explore each category: **Active Immunity:** Active immunity refers to the immune response that is generated within an individual's own immune system as a result of exposure to antigens, usually through infection or vaccination. It involves the activation of immune cells and the production of memory cells. Active immunity results in immune memory and lasting protection. - **Natural Active Immunity:** This occurs when an individual's immune system responds to actual infection with a pathogen. The immune response leads to the development of memory cells, ensuring that if the same pathogen is encountered again, the immune system can mount a rapid and effective response. - **Artificial Active Immunity:** This is achieved through vaccination. Vaccines contain weakened or inactivated forms of pathogens or pieces of antigens. When administered, vaccines stimulate the immune system to generate an immune response without causing the disease. This results in the production of memory cells and provides protection against future infections with the actual pathogen. **Passive Immunity:** Passive immunity involves the transfer of pre-formed antibodies or immune cells from one individual to another. It does not lead to the development of immune memory and lasting protection because the recipient's immune system is not actively involved in the response. - **Natural Passive Immunity:** This occurs when a baby receives antibodies from its mother through the placenta or breast milk. These antibodies provide temporary protection to the baby's immune system until it develops its own active immunity. - **Artificial Passive Immunity:** This involves the direct administration of antibodies produced by another individual or an animal. For example, injection of immune serum or specific antibodies can provide immediate but short-term protection against certain diseases. Since the recipient's immune system is not engaged, there is no development of memory cells or lasting protection. In summary: - Active immunity, both natural and artificial, results in immune memory and lasting protection because it involves the activation of the individual's immune system and the production of memory cells. - Passive immunity, both natural and artificial, does not result in immune memory and lasting protection because it does not involve the individual's immune system actively responding to the antigen. Vaccination, which falls under active artificial immunity, is a crucial method for generating immune memory and conferring long-term protection against infectious diseases without causing the disease itself.