PUNJAB BOARD CLASS 12 BIOLOGY GUESS QUESTION PAPER 2025

Punjab Board Class 12 Biology Guess Paper 2025

As the Punjab School Education Board (PSEB) Class 12 Biology exams for 2025 approach, students are diligently preparing to excel in this crucial subject. One valuable tool that many students utilize during their preparation is a guess paper. While not the actual exam, a well-crafted guess paper can provide significant insights into the expected exam pattern, important topics, and the overall structure of the question paper.

This blog post aims to provide students with a general understanding of what they might expect in the Punjab Board Class 12 Biology examination in 2025. By familiarizing themselves with potential key areas and the format of questions, students can strategically focus their studies and enhance their exam-taking skills. Remember that consistent effort, thorough understanding of the syllabus, and regular practice are key to achieving success in your board exams.

Guess papers are designed by experienced educators who analyze previous years' question papers, the current syllabus, and the relative importance of different chapters. They help students identify high-priority topics that are likely to be included in the upcoming examination. By working through a guess paper, students can assess their preparation level, identify their strengths and weaknesses, and allocate their study time accordingly.

It is important to note that a guess paper should be used as a supplementary tool and not the sole basis for your preparation. A comprehensive understanding of the entire syllabus is essential to perform well in the final examination. Use guess papers to guide your revision, practice answering different types of questions, and get a feel for the time management required during the actual exam.

We encourage all Punjab Board Class 12 Biology students preparing for the 2025 exams to utilize all available resources, including textbooks, notes, sample papers, and yes, even well-prepared guess papers, to maximize their chances of success. Stay focused, study diligently, and best of luck with your examinations!

PUNJAB BOARD CLASS 12 BIOLOGY GUESS QUESTION PAPER 2025

1. The phenomenon where the ovary develops into a fruit without fertilization is called.
   1. sexual reproduction.
   2. Parthenocarpy
   3. apomixis
   4. asexual reproduction.
2. Analogous organ arise due to
   1. convergent evolution
   2. artificial selection
   3. divergent evolution
   4. genetic drift
3. Uracil is present in RNA at the place of
   1. Guanine
   2. Cytosine
   3. Thymine
   4. Adenine
4. Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because:
   1. toxin is immature
   2. bacteria are resistant to strain
   3. toxin is inactive
   4. bacteria are not resistant to strain
5. which one of the following has a largest population in the food chain:
   1. producers
   2. secondary consumers
   3. Decomposers
   4. primary consumers
6. The term molecular scissors generally refers to
   1. DNA ligase
   2. restriction endonuclease
   3. DNA polymerase
   4. RNA polymerase
7. z z/z w type of sex determination is seen in
   1. snails.
   2. peacock
   3. platypus
   4. snakes
8. Tubectomy a method of population control is performed on
   1. male only.
   2. only pregnant women
   3. both male and female
   4. female only
9. Amensalism is an association between two species where:
   1. one species is harmed and other is unaffected
   2. both the species are harmed
   3. one species is benefitted and other unaffected
   4. one species is harmed and other is benefitted ted
10. the sporozoites that cause infection when a female Anopheles mosquito bite a human being are formed in:
    1. liver of human
    2. RBCs of mosquito
    3. intestine of human
    4. Salivary glands of mosquito.

B True or False

11. In parasitism one organism is benefited, other is harmed.
12. Zoological Park is an example of in situ conservation
13. Loss of biodiversity in a region may lead to extinction of species.
14. The second Trophic level in a Lake is Zooplanktons
15. The infective stage of Plasmodium that enters the human body is trophozoite

C true or Fill in the blanks

16. Ovulation is induced by a hormone called _________
17. _________ which is obtained from Trichoderma polysporum is used as immunosuppressive agent.
18. _________ is used for commercial production of ethanol.
19. The first restriction endonuclease is _________.
20. _________ is a high temperature tolerant enzyme used in PCR

2. Why is Apple called a false fruit? Which part of the flower forms a fruit?
3. Write the functions of the ovary.
4. What is amniocentesis? Why is it banned in India?
   OR
   What are the measures that should be taken to prevent STDs?
5. What is chromosomal theory and who proposed it?
   OR
   Differentiate between monohybrid and dihybrid cross.
6. What are analogous organs? Give an example.
7. What measures would you take to prevent waterborne diseases?
8. Do you think microbes can also be used as a source of energy. If yes, how?
9. Differentiate between plasmid DNA and chromosomal DNA.
   OR
   What is the down streaming process?
10. List any two recombinant proteins having therapeutic uses.
11. Distinguish between production and decomposition.
    OR
    Give the difference between in-situ and ex- situ conservation.
12. What is DNA fingerprinting? write its two applications.
    OR
    Why is the human genome project called a mega project?
13. What is adaptive radiation? Explain with an example.
14. List the harmful effects caused by alcohol and drug abuse
15. Draw a labelled diagram of pBR322.
    OR
    What is gene therapy?. illustrate using the example of adenosine deaminase deficiency
16. Write a short note on: a. Commensalism. b. Competition.
    OR
    What are sacred groves? Write an example.
17. Draw a labelled diagram of an anatropous ovule and explain its parts.
    OR
    What is the menstrual cycle. Which hormones regulate the menstrual cycle?
18. Explain replication of DNA with a diagram.
    OR
    Describe characteristics of chromosomal abnormalities:
    1. Trisomy of 21st chromosome
    2. XXO.
    3. XO

Q19. A stable self-supporting ecological unit, resulting from an interaction between biotic community, living organisms, and its biotic environment is called an ecosystem. An ecosystem comprises two main components, biotic, including plants, animals, microorganisms, abiotic, including substratum, water, minerals, pH, carbon dioxide, oxygen, and temperature. It must also receive a constant supply of light energy. It is convenient to divide it into two basic categories, namely the terrestrial and the aquatic. Forest, grassland, and desert are some examples of terrestrial ecosystems and pond, lake, wetland, river and estuary are some examples of aquatic ecosystems. Crop fields and an aquarium may also be considered as man made ecosystems.

19. What is an ecosystem?
20. Name two major kinds of ecosystem
21. Name three abiotic components of an ecosystem
22. Give one example of a man-made ecosystem.
23. Give one example of a terrestrial ecosystem.
    OR
    Describe various causes of loss of biodiversity.