CBSE Class 12th Biology Sample Paper 2024-25 Out, Download PDF with Answers

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The CBSE Class 12th Biology Sample Paper 2024-25 with solutions has been released by the Central Board of Secondary Education (CBSE) at its official website. All the students who are aspiring to appear in the CBSE Class 12th Final Exams 2024-25 to be held in February/ March 2025 can now download the sample papers from https://cbseacademic.nic.in/ along with the marking scheme.

While practicing for the final exams students will have better insights and opportunities to complete their preparations with the use of the CBSE 12th Biology Sample Papers 2025. The direct links to download the sample papers have been added below in the article.

CBSE Class 12 Biology Sample Paper 2024-25

For all the students who are currently studying in class 12 (Physics, Chemistry, and Biology) and are preparing to appear in the Board Examination, the CBSE Class 12 Sample Paper 2024-25 is now live on the official website. The sample papers have been designed and prepared in a manner to replicate the final exam paper so that students can easily prepare their best and can also analyze their performance in the sample paper by using the marking scheme containing the answers to all the questions.

The CBSE Class 12 Biology Sample Paper 2024-25 comprises all the important topics including Biological Classification, Plant Kingdom, Morphology of Flowering Plants, Structural Organisation in Animals, Cell Cycle and Cell Division, Breathing and Exchange of Gases, Excretory Products and their Elimination, etc.

CBSE Class 12 Biology Exam Pattern 2025

The CBSE Class 12th Biology Exam Paper 2025 is divided into 5 sections where students get to answer various types of questions including multiple choice questions, short answer questions, long answer questions, and others. Check the table below for the CBSE Class 12 Biology Exam Pattern 2025:

CBSE Class 12 Biology Exam Pattern 2025
Sections	Category	Marks	Number of Questions
Section A	Multiple Choice Questions (MCQs)	1 mark each	16
Section B	Very Short Answers (VSA)	2 marks each	5
Section C	Short Answers (SA)	3 marks each	7
Section D	Long Answers (LA)	5 marks each	2
Section E	Source-based/ Case-based	4 marks each	3

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

The Class 12 Biology Sample Paper has been uploaded by the board official at the online portal making them easily accessible for all the students who are pursuing their Class 12 from the medical stream. The sample papers cover all the important topics to ensure that students have the best practice before appearing for the final exams.

The direct links to check and download the CBSE Class 12 Biology Sample Paper 2024-25 PDF with Solutions have been added below in the table. Click on the link and download the sample paper along with the marking scheme.

CBSE Class 12 Biology Sample Paper 2024-25
Subject	Sample Question Paper (SQP)	Marking Scheme (MS)
Biology	Click Here	Click Here

Previous Year’s Biology Sample Paper Class 12 with Solutions

The table below contains the links to access the previous year’s Biology Sample Paper Class 12 with Solutions. Click on the link and access them for better practice:

Previous Year’s Biology Sample Paper Class 12 with Solutions
Year	Subject	Sample Question Paper (SQP)	Marking Scheme (MS)
2023	Biology	Click Here	Click Here
2022	Biology	Click Here	Click Here
2021	Biology (Term 1)	Click Here	Click Here
2021	Biology (Term 2)	Click Here	Click Here

CBSE Class 12 Biology Sample Questions 2024-25

Section – A

Q1. 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

Ans. B. Both placenta as well as fully developed foetus.

Q2. To produce 1600 seeds, the number of meiotic divisions required will be

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

Ans. B. 2000
Formation of one seed requires fertilsation between one pollen grain and one egg. To produce 1600 seeds, 1600 pollen grains and 1600 eggs will be required. Each microspore mother cell results in the formation of 4 pollen grains after one cycle of meiotic division. So, 400 meiotic divisions will result in the production of 1600 pollen grains. One megaspore mother cell after one cycle of meiotic division results in the formation of 1 egg; so, 1600 meiotic divisions will take place to form 1600 eggs. Thus, total number of meiotic divisions required for the formation of 1600 seeds will be 400 + 1600 =2000.

Q3. 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%

Ans. A. 23%
According to Chargaff’s rules, in DNA, A =T and G=C;
Thus, A +T+G+C =100
Given T = 27% so A=T =27%
Thus A+T = 27 +27 =54%
Thus, G+C =100 – 54 = 46%
Since G = C so G = 46/2 =23%

Q4. Suresh and Rajesh have defective hemoglobin due to genetic disorders. In Suresh, the problem is qualitative as he is having incorrectly functioning globin molecules while in Rajesh the problem is quantitative as he is having very few globin molecules. Identify the disorder they are suffering from.

	Suresh	Rajesh
A	Thalassemia – Autosomal Dominant blood disorder	Sickle Cell Anaemia – Autosomal linked Recessive trait
B	Sickle Cell Anaemia – Autosomal linked Dominant trait	Thalassemia – Autosomal Recessive blood disorder
C	Sickle Cell Anaemia – Autosomal linked Recessive trait	Thalassemia – Autosomal Recessive blood disorder
D	Thalassemia – Autosomal Dominant blood disorder	Sickle Cell Anaemia – Autosomal linked Dominant trait

Ans. C.

Suresh	Rajesh
Sickle Cell Anaemia – Autosomal linked Recessive trait	Thalassemia – Autosomal Recessive blood disorder

Q5. 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.

Ans. A. present in the medium and it binds to the repressor.