Final answer:
The examples of passive immunity are IgA transferred through breast milk and receiving antivenom after a spider bite. Passive immunity involves obtaining antibodies from an external source, providing immediate, but temporary protection without active response from the recipient's immune system.
Step-by-step explanation:
The examples of passive transfer of immunity from the options provided are b. IgA through breast milk and c. Antivenom after being bit by a spider, which makes the correct answer d. B&C.
Passive immunity arises from the transfer of antibodies to an individual without the need for their own immune system to respond actively. Naturally acquired passive immunity includes the transfer of IgG from mother to fetus via the placenta, and IgA through breast milk, delivering immediate protection to the child. Artificially acquired passive immunity is exemplified by treatments like antivenom injections, which offer rapid defense by introducing antibodies from other sources.
While passive immunity provides immediate protection, it is temporary and does not elicit immunological memory, meaning once the transferred antibodies degrade, the protection they offer ceases.