ISC Class 12 Biology Exam 2026 Repeated Questions

ISC Class 12 Biology Exam 2026 Repeated Questions will help students to test their preparation level along with the information of the types of questions asked in the exam. You can note down and put extra efforts on the topics from which the questions are being asked every year. Generally, the questions are repeated from the high-weightage topics, which you can check here: ISC Class 12 Biology Weightage 2026 . By regularly practicing the questions, students will learn to attempt all questions in board exams within the given time. Besides answering the repeated questions, students can also solve ISC Class 12 Biology Previous Year Question Papers and sample papers. This will introduce them to the variety of short and long questions. The regular practice will boost their confidence to improve performance in board exams. Go through the article in detail and solve all the questions.

Also Check ISC Class 12 Biology Weightage 2026

ISC Class 12 Biology Exam 2026 Repeated Questions

Q1. Define the species-area relationship. What is the significance of the slope of regression? Show with the help of a graph.

Q2. As a volunteer for an awareness programme in rural areas, you have been asked to design a poster on sexual health, highlighting birth control options available to males. What two contraceptive methods for males will you highlight in the poster that have negligible chances of failure? Mention the working principle for each method.

Q3. Microbes especially yeasts, have been used from time immemorial for the production of beverages like wine, beer, whisky, brandy, or rum. Depending on the type of raw materials used for fermentation and the type of processing (with or without distillation), different types of alcoholic drinks are obtained.

(i) Mention the scientific name of the organism used to prepare fermented beverages.
(ii) Name any one beverage obtained without distillation of fermented broth.

Q4. Give a reason for each of the following:

1. The second half of the menstrual cycle is called luteal phase as well as the secretory phase.
2. Streptokinase is administered to the patients having myocardial infarction.

Q5. How has biotechnology been useful in controlling nematode infection in plants? Explain the technique involved in this process.

Q6. Microbes are useful to human beings in diverse ways. Give the biological names of each of the following microbes:

(i) Lactic acid producing bacterium.
(ii) Microbe known as Baker’s yeast.
(iii) Fungus, which helps in the production of cyclosporin-A.
(iv) Microbe used in the production of statins.

Q7. A patient was given an anti-retroviral drug by the doctor.

(i) Which disease was the patient diagnosed with? Mention any one symptom of this disease.
(ii) Give the scientific name of the causative agent of this disease.
(iii) Which method was used to diagnose this disease?
(iv) What is the role of Reverse Transcriptase and Integrase in the life cycle of a retrovirus?

Also Read ISC Class 12 Biology Specimen Paper 2025-26

Q8. Give one difference between the following pairs: (i) Sites of maturation of B – Lymphocytes and T – Lymphocytes (ii) Sources of Opioids and Cannabinoids.

Q9. (i) In a barn, there were 30 rats. 5 more rats entered the barn and 6 of the rats were eaten by the cats in one week. If 8 rats were born during the same period and, during the same time, 7 rats left the barn, find the resultant rat population in the barn at the end of one week.
(ii) Define carrying capacity

Q10. The scientist from a research institute collected samples of water from sewage pipes of two different cities, A and B. On analysis, the BOD value of the sample from city A was found to be 500 mg/L. The BOD value of the sample from city B was 200 mg/L.
(i) Which one of the cities needs a sewage treatment plant?
(ii) Briefly discuss the steps involved in the treatment of sewage.
(iii) What will be the effect of sewage treatment on the value of BOD?

Keep visiting the page to solve the questions regularly and practice well for the board exams.