Read the passage and answer the question given below.
When a host is exposed to antigens, which may be in the form of living or dead microbes or other proteins, antibodies are produced in the host body. This type of immunity is called active immunity. Active immunity is slow and takes time to give its full effective response. Injecting the microbes deliberately during immunisation or infectious organisms gaining access into body during natural infection induce active immunity. When antibodies are directly given to protect the body against foreign agents, it is called passive immunity.
Immunity provided to the foetus from the mother through placenta during pregnancy is:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Passive immunity
Option (1) Active immunity — Incorrect. Active immunity needs the body to make its own antibodies after meeting an antigen; the foetus receives them.
Option (2) Passive immunity — Correct. When ready-made antibodies are given to a body, the protection is called passive immunity. The foetus receives antibodies from the mother through the placenta, so this is passive immunity.
Option (3) Non-specific immunity — Incorrect. Non-specific (innate) defence comes from barriers such as skin, acid and phagocytes; antibodies are specific.
Option (4) Innate immunity — Incorrect. Innate immunity is present from birth and does not depend on antibodies passed from the mother.
Note: The passage is taken from NCERT. NTA has put lines of the NCERT text together to make it. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.
NCERT Extract:
Active and Passive Immunity – “The yellowish fluid colostrum secreted by mother during the initial days of lactation has abundant antibodies (IgA) to protect the infant. The foetus also receives some antibodies from their mother, through the placenta during pregnancy. These are some examples of passive immunity.”