CBSE 2026 · Region 4 · Set 1 · Q30 · 4 marks
Read the following passage and answer the questions that follow : Immunity in our body is of two types (i) Innate immunity, and(ii)Acquired immunity. Innate immunity is a non-specific defence mechanism, whereas Acquired immunity is pathogen specific. Acquired immunity is characterised by memory. Antibodies are specific to antigens and there are four types of antibodies produced in our body - IgA, IgE, IgG and IgM. It shows primary response where it encounters the pathogen for the first time and secondary response during the subsequent encounters with the same antigen/pathogen. These immune responses are carried out with the help of two special types of lymphocytes present in the blood.(a)Name the two types of specialised cells which carry out the primary and secondary responses.(b)Name any two barriers present in our body that provide innate immunity.(ii)The organ transplants (grafts) are often rejected if not taken from suitable compatible persons. Mention the characteristic of our immune system that is responsible for the rejection.(c)How is active immunity different from passive immunity ? Write any two differences.
Read the following passage and answer the questions that follow : Immunity in our body is of two types (i) Innate immunity, and
(ii)
Acquired immunity. Innate immunity is a non-specific defence mechanism, whereas Acquired immunity is pathogen specific. Acquired immunity is characterised by memory. Antibodies are specific to antigens and there are four types of antibodies produced in our body - IgA, IgE, IgG and IgM. It shows primary response where it encounters the pathogen for the first time and secondary response during the subsequent encounters with the same antigen/pathogen. These immune responses are carried out with the help of two special types of lymphocytes present in the blood.
(a)
Name the two types of specialised cells which carry out the primary and secondary responses.
(b)
Name any two barriers present in our body that provide innate immunity.
(ii)
The organ transplants (grafts) are often rejected if not taken from suitable compatible persons. Mention the characteristic of our immune system that is responsible for the rejection.
(c)
How is active immunity different from passive immunity ? Write any two differences.
Marking-scheme solution
(a)
B – lymphocytes /B cells , and T – lymphocytes/ T Cells
(b)
Physical barrier , physiological barriers , Cellular barriers , Cytokine barriers
(ii)
Our immune system has the ability to distinguish between ‘self’ and ‘non-
self’ cells or tissues.
(c)
Active Immunity
Passive Immunity
When antibodies are produced in our body in response to an antigen then it is called active immunity.
When preformed antibodies are
injected into the body for protection then it is called passive immunity.
It is slow and takes time to give its full effective response.
It gives quick response.
It lasts for longer period.
It last for shorter period.
Memory cells are formed.
Memory cells are not formed.
Human Health and DiseaseImmunityUnderstandcase_studymedium
More from Human Health and Disease
- Name the category of drugs represented by the chemical structure given above. If the methyl group is…2023 · asked 3×
- Lactobacillus that sets milk into curd is categorised as:2024 · asked 3×
- Explain, giving two reasons, how immune response by "vaccine" is different from that by "antitoxin" in humans.2022 · asked 3×
- Student to attempt either option or. Describe any two situations where a medical doctor would recommend…2025 · asked 3×
- (i) Draw the structure of an antibody molecule and label any four of its parts. (ii) Differentiate between…2026 · asked 3×
- Assertion: Virus-infected cells produce interferons. Reason (R): Interferons can cause inflammation of…2024 · asked 3×
- Out of the following, select the correct match:2025 · asked 3×
- Though filariasis is not fatal, but the disease in humans is responsible for considerable suffering, gross…2022 · asked 3×
CBSE Class 12 Biology past-paper question from the 2026board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.