Class 12 Biology Sample Paper 2024-25 with Solutions, Download PDF

The Class 12 Biology sample paper 2024-25 has been released by the Central Board of Secondary Education for the board exam to be held in 2025. The Biology subject holds a significant importance not only in board exam but also in medical competitive exams.

Students who want to take up medicine as a career in their future, they must prepare the biology subject from the foundational level. Solving Class 12 Biology sample paper is one way to build a strong foundation in the Biology subject.

Class 12 Biology Sample Paper 2024-25

The board members and experienced teachers have created the class 12 Biology sample paper 2024-25 of the CBSE board. The same teachers and experts will also be formulating the board exam paper. That is why, it is always seen that the questions in the board exam question paper are repeated from the sample paper as it is. It makes it highly important for students to go through each question and concept present in the class 12 biology sample paper 2025.

CBSE Sample Paper 2024-25 Class 12 Biology

The Central Board of Secondary Education (CSBE) publishes the official sample paper before the board exam for every subject including biology. The Biology sample paper 2024-25 of class 12 contains the same pattern and marking scheme like the actual board exam paper for every question. Along with the cbse class 12 sample paper 2024-25, the education board has also released the official marking scheme and solutions of the sample questions.

Biology Sample Paper Class 12 2024-25 with Solutions

Check the sample paper questions for Class 12 Biology subject for the 2025 board exam below. Make sure to practice these questions and check answers with the official solutions provided in the article below.

Q) Signals for parturition in human female originate from

A. Fully developed foetus only
B. Both placenta as well as fully developed foetus
C. Placenta only
D. Oxytocin released from maternal pituitary

Q) To produce 1600 seeds, the number of meiotic divisions required will be

A. 2400
B. 2000
C. 1600
D. 1800

Q) A sample of normal double-stranded DNA was found to have thymine content of 27%. What will be the expected proportion of guanine in this strand?

A. 23%
B. 32%
C. 36%
D. 73%

Q) In E.coli, the lac operon gets switched on when lactose is

A. present in the medium and it binds to the repressor.
B. not present in the medium and the repressor binds to the operator.
C. not present in the medium and RNA polymerase binds to the operator.
D. Active lactose present in the medium binds to RNA polymerase.

Q) Which of the following features shows the mechanism of sex determination in honey-bee?

(i) An offspring formed from the union of a sperm and egg develops as a female.
(ii) Males have half the number of chromosomes than that of female.
(iii) The males are haploid having 32 chromosomes.
(iv) All workers and males are diploid having 16 chromosomes

A. (i) and (ii)
B. (ii) and (iii)
C. (i) and (iv)
D. (ii) and (iv)

Q) The following diagram shows a fragment of DNA which is going to be transcribed, the upper strand with polarity 3’ to 5’ is the template strand:
3´ ATTGCC 5´
5´ TAACGG 3´

After transcription the mRNA can be represented by:
A. 5´ AUUGCC 3´
B. 5´ AUUGCC 3’
C. 5´ UAACGG 3´
D. 5´ GGCAAU 3´

Q) Idli – dosa dough rises due to production of which of the following gas?

A. CO
B. CO2
C. NO
D. NO2

Q) Adaptive radiation leads to which of the following?
A. Increased competition among species
B. Decreased speciation rates
C. Limited morphological diversity among species
D. Rapid divergence of traits among populations inhabiting a given geographical area.

Q) During the secondary treatment of sewage, which of the following change in the effluent occur due to flocs?

A. Reduction in BOD
B. Increase in BOD
C. Decrease in DO
D. No change in DO or BOD

Q) (i) A blood test reported negative for hCG. What does negative hCG imply? Name the tissue which produces hCG?

(ii) If a blood test reported positive for hCG in a person, then which other hormones would also be secreted by the tissue secreting hCG?

Q) (i) The human male ejaculates about 200 to 300 million sperm during a coitus, however the ovum is fertilized by only one sperm. How does the ovum block the entry of additional sperms?

(ii) All copulations will not lead to fertilization. Why?

Q) A culture plate of Lactobacillus shows blue-coloured colonies and colourless colonies. Explain the principle involved in the formation of such variance in the colour of colonies.

Q) (i) It was estimated that if an evergreen forest has a GPP of 400J/m²/day and 150 J/m²/day worth of carbon dioxide flows out of that forest, what is the NPP in that forest?

(ii) Explain why pyramids of energy must always be upright.

Q) Each Mango fruit contains one seed. Two mango seeds, X and Y were sown in the soil. From Seed X, 3 plant saplings germinated but from seed Y only 1 plant sapling germinated.

A. For seed X which is apomictic, calculate the number of:
i) Embryo(s)
ii) Embryo sac(s)
iii) Ovules in this seed’s ovary

B. How multiples embryos are formed in citrus fruits?

C. What advantage will plants developed from seed Y have over seed X?

Q) Name the place in human ovary where the first meiotic division is completed during oogenesis. What are the products of this division? Give the chromosome number of each type of cells involved in the process.

Q) Describe the steps involved in Southern blot hybridization using radiolabeled VNTR as a probe.

Q) Bio-fertilisers are organisms that enrich the nutrient quality in the soil. Explain the role of three main sources of bio-fertilisers.

Q) Explain how PCR technique can be used for amplification of a small amount of DNA template.

Class 12 Biology Sample Paper 2024-25 with Answers PDF Download

The CBSE class 12 Biology sample paper 2024-25 along with the official solutions and marking scheme has been provided below in PDF format. Download the official resources provided by the CBSE and make use of it to score good marks in the 2025 board exam.

Download CSBE Class 12 Biology Sample Paper 2024-25 PDF

Download CSBE Class 12 Biology Sample Paper Solutions and Marking Scheme 2024-25

Advantages of Solving Biology Sample Paper Class 12 with Solution

Students can improve their scores in the CBSE 12th Biology Board Exam 2024-25 by practicing the class 12 Biology sample paper of the CBSE board. It is suggested that students should also solve the CBSE Class 12 Biology question paper from the previous year to prepare for the upcoming CBSE Biology Board Exam in 2025. Below are the advantages of solving the CBSE 12th Biology sample paper.

• Students will comprehend the marking scheme and exam pattern for the Class 12 Biology board exam in 2025.
• Looking at Biology sample paper can assist students in identifying the key and commonly asked questions.
• Solving sample paper aids in achieving higher grades in the CBSE Board Exam for Class 12 Biology.
• Familiarize yourself with the kinds of questions that will be included in the CBSE 12th Biology Board Exam in 2025.
• Students can know their readiness for the CBSE 12th Biology board Paper 2025.

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