Which of the following vaccines is typically recommended for adolescents to protect against certain types of cancer?

Explanation: Receiving antibodies through placenta during pregnancy. Passive immunity is acquired when preformed antibodies are transferred from one individual to another, providing immediate but temporary protection. This can occur naturally through breastfeeding or artificially through administration of preformed antibodies, as in the case of placental transfer of antibodies from a mother to her baby.

Incorrect choices:

a. Receiving a flu vaccine involves active immunity, where the body is exposed to an attenuated or inactivated pathogen to stimulate the production of antibodies and memory cells for long-term protection.

b. Developing immunity after recovering from a viral infection is an example of active immunity, where the body mounts an immune response and produces memory cells to provide long-lasting protection against the pathogen.

d. Producing memory cells after exposure to a pathogen is part of the adaptive immune response and contributes to long-term immunity, not passive immunity.

Explanation: B cells are a type of lymphocyte that plays a central role in the adaptive immune response. When activated by the presence of specific antigens, B cells differentiate into plasma cells, which are responsible for producing large quantities of antibodies that can target and neutralize the invading pathogen.

Incorrect choices:

a. T cells are another type of lymphocyte that is involved in cell-mediated immunity, where they directly attack infected or abnormal cells. They do not produce antibodies.

b. Natural killer cells are part of the innate immune system and are responsible for killing infected or cancerous cells. They are not involved in antibody production.

d. Macrophages are phagocytic cells that engulf and destroy pathogens and debris in the body. While they play a crucial role in immune responses, they do not produce antibodies.