ISC 2024 Biology Question Paper for Class 12

About this paper

This is ISC Class 12 Biology Paper 1 (Theory), code 863A, from the 2024 board examination set by CISCE. The footer reads 1224-863A. It carries 70 marks, runs for three hours plus fifteen minutes of reading time, and has 18 compulsory questions in four sections, with an internal choice in one question each in Sections B, C and D. Section A is a single 20-mark question of short items, including two assertion–reason questions, a match on weeks of pregnancy, and a pedigree of thalassaemia. Later questions use diagrams of endosperm types, cloning vectors, growth curves and proinsulin, and Section D closes with Griffith's experiment on Diplococcus pneumoniae. This copy has the questions only.

Exam

ISC Class 12

Subject

Biology

Year

2024

Paper code

863A

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

18

Pages

11

Answers included

No, questions only

Paper pattern

• Section A

  20 marks

  Question 1, sub-parts of one or two marks: short answers, multiple-choice and assertion–reason items, a match and a pedigree

• Section B

  14 marks

  Questions 2–8, two marks each; internal choice in one question

• Section C

  21 marks

  Questions 9–15, three marks each; internal choice in one question

• Section D

  15 marks

  Questions 16–18, five marks each; internal choice in one question

Topics covered

• Human health and disease
• Reproductive health
• Human reproduction
• Sexual reproduction in flowering plants
• Principles of inheritance and variation
• Molecular basis of inheritance
• Evolution
• Organisms and populations
• Ecosystem
• Biodiversity and conservation
• Microbes in human welfare
• Biotechnology and its applications

Questions from this paper

1. In human plasma, five different types of immunoglobulins are found. Which type is responsible for allergic reactions?
2. A haemophilic man marries a carrier woman, and they have a daughter. What is the probability of their daughter being haemophilic?
3. Home-made fruit juices are turbid, while bottled fruit juices from the market are clear. Give a reason for this difference.
4. The number of lily plants in a pond was 50. After one year it rose to 65. Calculate the natality of the lily plants.
5. A male plant bearing red flowers was crossed with a female plant bearing yellow flowers. In the F1 all the flowers were orange. Give a reason, and state the ratio of red, yellow and orange flowers in the F2.
6. Write the scientific name of the causative agent and the mode of transmission of filariasis and of typhoid.