Subject

Biology

Class

CBSE Class 12

Pre Boards

Practice to excel and get familiar with the paper pattern and the type of questions. Check you answers with answer keys provided.

Sample Papers

Download the PDF Sample Papers Free for off line practice and view the Solutions online.
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 Multiple Choice QuestionsShort Answer Type

11.

Differentiate between albuminous and non-albuminous seeds, giving one example of each.

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12. Explain the process of RNA interference.
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13. List the key tools used in recombinant DNA technology.
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14. Name the two types of immune systems in a human body. Why are cell-mediated and humoral immunities so called?
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15.

Write the scientific names of the causal organisms of elephantiasis and ringworm in humans. Mention the body parts affected by them.

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16. Justify with the help of an example where a deliberate attempt by humans has led to the extinction of a particular species.
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17. Identify A, D, E and F in the diagram of an antibody molecule given below.

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18.

Study the graph given below. Explain how oxygen concentration is affected in the river when sewage is discharged into it.

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19. Explain how a hereditary disease can be corrected. Give an example of first successful attempt made towards correction of such diseases.


Gene therapy can be used to correct hereditary diseases. It involves delivery of a normal gene into the individual or embryo to take over the function of and compensate for the non-functional gene.

The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency. In this disease, the gene coding for enzyme ADA gets deleted leading to deficiency of ADA and problems in immune system. Gene therapy for ADA deficiency includes isolation of lymphocytes from patient’s blood, culturing them in-vitro, introduction of functional ADA cDNA and returning the cells to the patient’s body.

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20. Draw a diagram of a male gametophyte of an angiosperm. Label any four parts. Why sporopollenin is considered the most resistant organic material?
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