Class 12 Biology Sample Paper 2023-24

Class 12 Biology Sample Paper 2023-24: Solving the CBSE sample question papers Class 12 is a good way to prepare for the upcoming Class 12 Board exams. The CBSE Class 12 Biology board exam is scheduled for March 19, 2024. To excel in this exam, it is crucial to practice CBSE Class 12 Biology model question papers that follow the latest Class 12 Biology syllabus and exam pattern.

The CBSE Class 12 Biology Sample Paper 2023-24 serves as an invaluable resource for students, offering an idea about the types of questions they can expect in the Class 12 Biology board exam. These biology sample papers class 12 are prepared by our subject matter experts to cover all essential topics comprehensively.

CBSE Class 12 Sample Paper 2023-24 Biology

The biology class 12 sample paper 2024 CBSE is given below:

Section A: Objective Type Questions (1 mark each)

Question 1: An infertile couple was advised to undergo In Vitro Fertilization (IVF) by the doctor. Out of the options given below, select the correct stage for transfer to the fallopian tube for successful results.

• (a) Zygote only
• (b) Zygote or early embryo up to 8 blastomeres
• (c) Embryos with more than 8 blastomeres
• (d) Blastocyst stage

Question 2: Given below are four contraceptive methods and their modes of action. Select the correct match:

• Method:
  • (i) Condom
  • (ii) Vasectomy
  • (iii) Pill
  • (iv) Tubectomy
• Mode of action:
  • (a) Prevents ovulation
  • (b) Prevents sperm from reaching the cervix
  • (c) Semen contains no sperms
  • (d) Ovum not able to reach Fallopian tube
• (a) (i)–(b), (ii)–(c), (iii)–(a), (iv)–(d)
• (b) (i)–(d), (ii)–(a), (iii)–(b), (iv)–(c)
• (c) (i)–(b), (ii)–(d), (iii)–(a), (iv)–(c)
• (d) (i)–(c), (ii)–(b), (iii)–(d), (iv)–(a)

Question 3: Which of the following amino acid residues will constitute the histone core?

• (a) Lysine and Arginine
• (b) Asparagine and Arginine
• (c) Glutamine and Lysine
• (d) Asparagine and Glutamine

Question 4: Evolutionary convergence is the development of:

• (a) A common set of functions in groups of different ancestry.
• (b) A dissimilar set of functions in closely related groups.
• (c) A common set of structures in closely related groups.
• (d) A dissimilar set of functions in unrelated groups.

Question 5: Apis mellifera, known as killer bees, possess toxic bee venom. Identify the treatment and the type of immunity developed from the given table to treat a person against the venom of this bee.

• (a) Inactivated proteins – Active immunity
• (b) Proteins of the venom – Active immunity
• (c) Preformed antibodies – Passive immunity
• (d) Dead micro-organisms – Active immunity

Question 6: Interferons are most effective in making non-infected cells resistant against the spread of which of the following diseases in humans?

• (a) Ascariasis
• (b) Ringworm
• (c) Amoebiasis
• (d) AID

Question 7: Which of the following processes contributes directly to genetic variation in sexually reproducing organisms?

• (a) Mitosis
• (b) Meiosis
• (c) Binary fission
• (d) Budding

Question 8: In the context of ecosystem services, what role do forests play in carbon sequestration?

• (a) Source of carbon dioxide
• (b) Sink for carbon dioxide
• (c) Source of oxygen only
• (d) Neither source nor sink of carbon dioxide

Question 9: The symbiotic association of fungi and roots of higher plants is termed:

• (a) Commensalism
• (b) Mutualism
• (c) Parasitism
• (d) Amensalism

Question 10: Which of the following is not a characteristic feature of cancerous cells?

• (a) Controlled division
• (b) Ability to metastasize
• (c) Loss of contact inhibition
• (d) Increased telomerase activity

Question 11: An example of a gene therapy for the treatment of ADA deficiency is:

• (a) Introduction of an enzyme-producing gene into bone marrow cells
• (b) Removal of ADA genes from the patient
• (c) Transfusion of ADA enzymes
• (d) Use of retroviral vectors to introduce ADA inhibitors

Question 12: The image below shows the cross-section of a leaf, with several structures labeled A, B, C, and D.

• (A) represents the waxy cuticle layer
• (B) is the palisade mesophyll
• (C) indicates the spongy mesophyll
• (D) shows the stomata

Based on the functions of these structures, answer the following question:

Which structure(s) is primarily involved in gas exchange and transpiration in the leaf?

• (a) A only
• (b) B only
• (c) C only
• (d) D only

Questions 13 to 16: Assertion and Reason

Question 13:

Assertion (A): The genetic material of a bacteriophage can integrate into the host bacterial chromosome.

Reason (R): Integration helps the bacteriophage DNA replicate along with the host DNA during cell division.

Options:

• (A) Both A and R are true, and R is the correct explanation of A.
• (B) Both A and R are true, but R is not the correct explanation of A.
• (C) A is true, but R is false.
• (D) A is false, but R is true.

Question 14:

Assertion (A): Genetic recombination during meiosis leads to variation in offspring.

Reason (R): Crossing over between homologous chromosomes occurs during prophase I of meiosis.

Options:

• (A) Both A and R are true, and R is the correct explanation of A.
• (B) Both A and R are true, but R is not the correct explanation of A.
• (C) A is true, but R is false.
• (D) A is false, but R is true.

Question 15:

Assertion (A): Deforestation leads to a decrease in biodiversity.

Reason (R): Trees provide a habitat and food sources for a wide range of organisms.

Options:

• (A) Both A and R are true, and R is the correct explanation of A.
• (B) Both A and R are true, but R is not the correct explanation of A.
• (C) A is true, but R is false.
• (D) A is false, but R is true.

Question 16:

Assertion (A): In a population obeying Hardy-Weinberg equilibrium, allele frequencies remain constant.

Reason (R): Hardy-Weinberg equilibrium requires no mutation, migration, genetic drift, selection, or random mating.

Options:

• (A) Both A and R are true, and R is the correct explanation of A.
• (B) Both A and R are true, but R is not the correct explanation of A.
• (C) A is true, but R is false.
• (D) A is false, but R is true.

Section B: Short Answer Questions (2 marks each)

Question 17: A diagram depicts the stages of meiosis in an animal cell.

• (a) Identify the stage represented in the diagram.
• (b) Explain the significance of this stage in genetic diversity.

Question 18: Consider the following scenario in an ecosystem: A species of plants in a forest area has developed resistance to a widespread pathogenic fungus.

• (a) Explain the possible genetic basis of this resistance.
• (b) Discuss how this resistance could affect the ecosystem’s biodiversity.

Question 19: Describe the process of RNA interference (RNAi).

• (a) Explain the role of RNAi in gene regulation.
• (b) Give one example of its application in biotechnology.

Question 20: A graph shows the fluctuation of two hormones (A and B) during the menstrual cycle.

• (a) Name the hormones represented as A and B.
• (b) Describe the effects of hormone B on the endometrium.

Question 21: Refer to the given diagram of a food web in a freshwater ecosystem.

• (a) Identify the primary producers.
• (b) Explain the role of decomposers in this ecosystem.

Section C: Long Answer Questions (3 marks each)

Question 22: Explain the structural and functional differences between RNA and DNA.

• (a) Compare the types of sugar found in RNA and DNA.
• (b) Describe the types of base pairing observed in RNA and how it differs from DNA.
• (c) Explain how the structure of RNA allows it to perform various functions within the cell.

Question 23: Discuss the process of transcription in eukaryotes.

• (a) Outline the steps involved in the initiation of transcription.
• (b) Explain the role of RNA polymerase II and the significance of the promoter region.
• (c) Describe the processing that pre-mRNA undergoes before becoming mature mRNA.

Question 24: Describe the process of ecological succession in a terrestrial ecosystem.

• (a) Define ecological succession and distinguish between primary and secondary succession.
• (b) Explain the concept of climax community with an example.
• (c) Discuss how succession contributes to biodiversity in an ecosystem.

Question 25: Explain the mechanism of gene expression regulation in prokaryotes using the Lac operon model.

• (a) Describe the structure of the Lac operon and the role of each component.
• (b) Explain how the presence or absence of lactose affects the expression of genes in the Lac operon.
• (c) Discuss the significance of the Lac operon model in understanding gene regulation.

Question 26: Discuss the impact of human activities on biodiversity and suggest measures for conservation.

• (a) Identify three human activities that have a significant impact on biodiversity.
• (b) Discuss the concept of biodiversity hotspots and their importance in conservation.
• (c) Suggest three measures that can be taken to conserve biodiversity.

Question 27: Explain the process and significance of recombinant DNA technology in medical science.

• (a) Outline the steps involved in creating a recombinant DNA molecule.
• (b) Discuss the role of recombinant DNA technology in the production of insulin.
• (c) Explain how gene therapy is used to treat genetic disorders, providing an example.

Section D: Case-Based Questions

Question 29: A study was conducted to observe the effects of pollution on aquatic life in a lake over a year. The concentration of various pollutants and their impact on the fish population were recorded. Based on the data:

• (a) Describe the observed relationship between pollutant concentration and fish population size.
• (b) If one type of pollutant was found to reduce oxygen levels in water, explain how this affects the fish population.
• (c) Given that certain algae species flourished with increased nutrient pollution, leading to algal blooms, discuss the potential long-term impacts on the lake’s ecosystem.

OR

• (c) If measures were implemented to reduce the inflow of nutrients into the lake halfway through the study, hypothesize the subsequent changes observed in the algal population and overall water quality.

Question 30: Researchers introduced a genetically modified crop designed to resist a common pest in agricultural fields. The crop produces a toxin that targets the digestive system of the pest, reducing crop damage. The effectiveness of the crop was monitored by comparing it with non-modified crops in adjacent fields.

• (a) Evaluate the effectiveness of the genetically modified crop based on the observed levels of pest activity and crop yield.
• (b) Discuss the implications of widespread use of genetically modified crops for pest resistance on local biodiversity.
• (c) Considering the potential development of resistance in pests to the genetically modified crop, suggest strategies that farmers could use to manage pest resistance effectively.

OR

• (c) If the genetically modified crop also showed unexpected effects on non-target insect species beneficial to the ecosystem, describe the potential ecological consequences and recommend measures to mitigate these impacts.

Section E: Detailed Answer Questions

Question 31: Discuss the steps involved in the process of artificial selection and its implications on biodiversity. Compare it with natural selection in terms of process and outcome.

OR

Question 31: Describe the structure and function of different types of RNA in the process of protein synthesis. Include in your answer the roles of mRNA, tRNA, and rRNA.

Question 32: Analyze the significance of biodiversity conservation in the context of climate change. Discuss:

• (a) The relationship between biodiversity and climate change.
• (b) The effects of climate change on global biodiversity.
• (c) Strategies for conserving biodiversity to combat climate change impacts

OR

Question 32: Elaborate on the process of eutrophication in freshwater ecosystems. Discuss:

• (a) The sequence of events leading to eutrophication.
• (b) The ecological impacts on aquatic life and biodiversity.
• (c) Possible mitigation strategies to prevent or reduce eutrophication.

Question 33: Describe the process of nitrogen fixation in legumes, highlighting the symbiotic relationship between legume plants and nitrogen-fixing bacteria.

• (a) Explain the role of nodules and the specific bacteria involved.
• (b) Discuss the benefits of nitrogen fixation for the plant and the ecosystem.
• (c) How does this process contribute to soil fertility?

OR

Question 33: Discuss the implications of gene flow and genetic drift on the genetic diversity of a population.

• (a) Define gene flow and genetic drift, providing examples of each.
• (b) Explain how these processes affect population genetics.
• (c) Discuss the importance of genetic diversity for species survival and adaptation.

These questions are designed to test students’ deep understanding of biological concepts, their ability to integrate knowledge from different parts of the curriculum, and their skills in applying this knowledge to explain complex processes and phenomena.

Conclusion – Sample Question Paper Class 12 – Biology

Students should solve the sample paper for class 12 biology to get a better understanding of the type of questions asked in the exams. The Class 12 Biology Sample Paper 2023-24 provided by Geeks for Geeks match the difficulty level of the actual Class 12 board exam. Solving these biology model question paper 2023-24 will boost your exam preparation. You can also practice CBSE sample paper class 12 biology 2023-24 with solutions.

FAQs – CBSE Class 12 Biology Sample Paper

Where can I Find Class 12 Biology Sample Paper 2024 with Answers pdf?

You can find the Class 12 biology sample paper 2023-24 with answers pdf on official site of Geeks for Geeks.

Is NCERT-Based Preparation Enough for Class 12 Biology Boards?

NCERT is the best CBSE Class 12 Biology book to prepare for Class 12 board exams. Pair it with other reliable reference biology books to score 95% and above in biology board exam.

Which is the Best Sample Paper Book for Class 12 in 2024?

You can find high-quality sample papers for Class 12 Biology on the official Geeks for Geeks website. These papers are designed to match the difficulty level of the actual Class 12 board exams ensuring comprehensive preparation.

Why Solving Biology Sample Question Papers are Important?

Solving biology sample question papers helps in familiarizing students with the exam pattern, tests their understanding of concepts, and identify areas for improvement which is helpful in obtaining good marks.

Where can I Download all the CBSE Class 12 Sample Paper 2023- 24 PDFs?

You can find all the sample question papers of CBSE Class 12 in CBSE Board’s official website.

Are Boards Easier than Sample Paper?

Boards are usually similar in difficulty to sample papers aiming to check your understanding of the subject matter effectively.

Which Sample Papers are Good for Class 12?

Geeks for geeks provides the best quality sample papers with similar marking scheme and questions type. The subject matter experts carefully craft each question to match the difficulty level of CBSE Class 12 biology board exam.