Table of Contents
Students who have opted for the medical stream in their Class 12 know how important it is to completely learn the concepts of the Class 12 Biology subject. The concepts and topics mentioned in the CBSE Class 12 Biology book are not only important for the Class 12 board exam but also medical exams like NEET UG. So, students must prepare for the Biology subject with full dedication. CBSE has come to the rescue of medical students and has released the sample paper for the Biology subject.
Biology Sample Paper Class 12 2024
The CBSE biology sample paper class 12 2024 for the new academic term has been published by the Central Board of Secondary Education (CBSE) on its official website.
We have given direct download links in this article for students to download the CBSE Class 12 Biology Sample Paper 2024 to prepare well for their Class 12 science stream exam preparation. The CBSE biology sample paper class 12 2024 is discussed in this post, so check all sections’ Biology questions with solutions.
Check: CBSE Class 12 Biology Syllabus 2024 with Deleted Topics
Class 12 Biology Sample Paper 2024: Exam Pattern
The CBSE sample papers are the best resource that mimics the actual exam paper. The official sample papers give the detailed information regarding the marking scheme and the exam pattern. There are 5 sections in the CBSE Class 12 Biology Sample Question Paper. Other significant features of the CBSE Class 12 Biology Sample Paper PDF are listed below –
(i) All of the answers are required.
(ii) The question paper is divided into five parts and contains 33 questions. All responses are required.
(iii) Section A contains 16 questions worth one point each; Section B contains 5 questions worth two points each; Section C contains 7 questions worth three points each; Section D contains two case-based questions worth four points each; and Section E contains three questions worth five points each.
(iv) There is no overall option. Internal choices have been given in some queries, however. In these kinds of questions, students must try only one of the alternatives.
(v) Wherever possible, neatly labeled diagrams should be made.
Sample Paper Class 12 Biology 2023-24 With Solutions
The official class 12 biology sample paper 2024 with answers pdf is given below for the board students. Students must solve the entire sample question paper and review their answers. They should solve the doubts they encounter while solving the sample paper.
Class 12 Biology Sample Paper 2024 with Answers Pdf Download
We have independently given the Class 12 Biology Sample Paper 2024 with Answers PDF Download link as well as the Class 12 marking scheme. The CBSE Class 12 Biology Sample paper PDF link is provided below.
| Biology Sample Question paper 2024 with answers pdf |
| Class 12 Biology Sample paper 2024 PDF Download |
| CBSE Class 12 Biology Sample paper 2024 with Answers PDF Download |
Biology Sample Paper Class 12 2024: Section A
Section A
( Each Question 1 Mark)
1. Remnants of nucellus are persistent during seed development in:
a) pea
b) groundnut
c) wheat
d) black pepper
Answer: d) black pepper
2. The wall layer of microsporangium which nourishes the pollen grain is:
a) epidermis
b) endothecium
c) middle layers
d) tapetum
Answer: d) tapetum
3. A short piece of DNA, having 20 base pairs, was analyzed to find the number of
nucleotide bases in each of the polynucleotide strands. Some of the results are
shown in the table.
| Number of nucleotide bases | ||||
| Adenine | Cytosine | Guanine | Thymine | |
| Strand 1 | 4 | 4 | ||
| Strand 2 | 5 | |||
How many nucleotides containing Adenine were present in strand 2?
a) 2
b) 4
c) 5
d) 7
Answer: d) 7
4. In a certain species of insects, some have 13 chromosomes, and the others have
14chromosomes.The 13 and 14 chromosome bearing organisms are
a) males and females, respectively
b) females and males, respectively
c) all males
d) all females
Answer: a) males and females, respectively
5. At a particular locus, the frequency of allele A is 0.8 and that of allele a is 0.2.
What would be the frequency of heterozygotes in a random mating population at
equilibrium?
a) 0.32
b) 0.16
c) 0.24
d) 0.48
Answer: a) 0.32
6. Variations caused due to mutations are
a) random and directionless
b) random and directional
c) random and small
d) random, small and directional
Answer: a) random and directionless
7. What is the smallest part of a DNA molecule that can be changed by a point
mutation?
a) Oligonucleotide
b) Codon
c) Gene
d) Nucleotide
Answer: d) Nucleotide
8 . What should be the genotype of the indicated member?
a) AA
b) Aa
c) XY
d) aa
Answer: d) aa
9. A patient was advised to have a kidney transplant. To suppress the immune
reaction, the doctor would administer him:
a) statins produced from Monascus purpureus
b) statins produced from Streptococcus thermophilus
c) cyclosporin A produced from Trichoderma polysporum
d) cyclosporin A produced from Clostridium butylicum
Answer: c) Cyclosporin A produced from Trichoderma polysporum
10. Identify the activity of endonuclease and exonuclease in the given image.
Answer: (d)
11. The main objective of the production of pest-resistant GM crops is to
a) encourage eco-friendly pesticides
b) reduce pesticide accumulation in food chain
c) eliminate pests from the field without the use of manual labour
d) retain maximum nutritional content in the crop that would be otherwise
consumed by pest
Answer: b) Reduce pesticide accumulation in food chain
12. Observe the contents 1,2,3 and 4 of soil samples A,B and C shown in the graph. If
the temperature and soil moisture of all soil samples are identical, which soil
sample (s) will show faster decomposition?
a) Soil Sample A
b) Soil Sample B
c) Soil Samples A and B both
d) Soil Sample C
Answer: d) Soil Sample C
Questions No. 13 to 16 consist of two statements – Assertion (A) and Reason (R). Answer these
questions selecting the appropriate option given below:
a) Both A and R are true and R is the correct explanation of A.
b) Both A and R are true and R is not the correct explanation of A.
c) A is true but R is false.
d) A is false but R is true.
13 Assertion: Primary endosperm nucleus is diploid.
Reason: It is the product of double fertilization.
Answer: d) A is false but R is true
14. Assertion: Ribosomal RNA is synthesized in the nucleus of the cell.
Reason: It is translated with the enzyme RNA polymerase III.
Answer: c) A is true but R is false
15. Assertion: Smoking can raise blood pressure and increase heart rate.
Reason: Nicotine stimulates adrenal glands to release adrenaline and noradrenaline into the blood circulation, both of which raise blood pressure and
increase heart rate.
Answer: a) Both A and R are true and R is the correct explanation of A.
16. Assertion: PCR is a powerful technique to identify genetic disorders.
Reason: PCR can detect mutations in low amounts of DNA.
Answer: a) Both A and R are true and R is the correct explanation of A.
Biology Sample Paper Class 12 2024 : Section B
Section B
( Each Question 2 Mark)
17. Explain the process of hormonal regulation of spermatogenesis.
18. The diagram below shows the sequence of amino acids in part of a haemoglobin
molecule.
a) If the base T* was substituted with A, how would it affect the hemoglobin
chain?
b) Name the condition and the effects associated with the above substitution.
19. The graph given below indicates the administration of the first (L) and second dose
(M) of a vaccine. The corresponding response of the body is indicated by X and Y.
Interpret the graph and explain the reason for such a response shown by the
body.
20. The image below shows the result of plating bacteria in chromogenic medium after
incorporating the gene of interest in plasmid. Some plates had blue colonies; some
plates had white colonies. A single bacterium extracted from Plate I,II,III is shown
below:
On the basis of your observations
a) Identify the plate(s) which is/are white. Give a reason.
b) Identify the plate(s) which is/are blue. Give a reason.
21. Biomass of a standing crop of phytoplankton is 4 kg/m2 which supports a large
standing crop of zooplankton having a biomass of 11 kg/m2. This is consumed by
small fishes having a biomass of 25 kg/m2 which are then consumed by large fishes with
a biomass of 37 kg/m2.
Draw an ecological pyramid indicating the biomass at each stage and also name the
trophic levels. Mention whether it is an upright or inverted pyramid.
OR
Use the information provided in the table given below to answer the following
questions:
a) Calculate the gross primary productivity.
b) Analyze the trend in the Net Production from Producers to Top
Carnivore. Give a reason for your observation.
Biology Sample Paper Class 12 2024 with Solutions: Section C
Section C
( Each Question 3 Mark)
22. The figure given below shows 3 sperms A, B and C.
a) Which one of the three sperms will gain entry into the ovum?
b) Describe the associated changes induced by it on P and Q.
23. Explain the phases in embryonic development from the morula stage till the
establishment of pregnancy in a human female.
24. A pregnant human female was advised to undergo MTP. It was diagnosed that the fetus she was carrying had developed from a zygote having 45 chromosomes with only one X chromosome.
a) What is this condition called and how does it arise?
b) Why was she advised to undergo MTP?
25. The graphs below show three types of natural selection. The shaded areas marked with arrows show the individuals in the population who are not selected. The dotted vertical lines show the statistical means.
a) What names are given to the types of selection shown in graphs A, B
and C.
b) After the selection has operated for several generations in the above
populations indicated as Graph A, B and C, graphically illustrate the probable
results.
26. The aeration tank of a sewage treatment plant is not functioning properly. Explain in detail the impact of this on the treatment of sewage and BOD of the effluent.
27. A farmer grew 2 varieties of corn crop in field A and B. He grew normal corn crops in field A and GM corn crops in field B. He observed corn borers attacked only in field A. To control it, spores of Bt were sprayed in field A.
a) Name the gene in the spores responsible for the control of this pest.
b) What effect will the spores of Bt have on the insect pest?
c) How has field B developed resistance against this pest?
OR
Lipoprotein lipase deficiency (LPLD)is a genetic disorder in which a person has a defective gene for lipase. This leads to high triglycerides, stomach pain, and fat deposits under the skin. It may eventually affect the liver, and pancreas and may also cause diabetes. The disorder occurs if a child acquires defective genes from both parents (autosomal recessive). ERT (enzyme replacement treatment) is one of the treatments offered to patients with LPLD.
a) (i) What procedure is followed in ERT?
(ii) What could be one possible drawback of ERT?
b) How can LPLD be treated using Biotechnology? Elaborate.
28. Give three reasons as to why the prokaryotes are not given any figures for their
diversity by the ecologists.
Biology Sample Paper Class 12 2024: Section D
Section D
(Each Question 4 Marks)
Q. No. 29 and 30 are case-based questions. Each question has 3 subparts with internal choice in one
subpart.
29. The structure below shows pUC18 which is similar to pBR322 in its function. However, they differ in some of their restriction sites and number of ori. The ori number for pBR322 is approximately 20.
a) How are puc18 and pBR322 used in biotechnological studies?
OR
What will be the impact if oriin the above structure gets damaged?
b) The lac z gene has many recognition sites. Study the segment of DNA given below and answer the questions
5’… ATC GTA AAG CTT CAT…3’
3’… TAG CAT TTC GAA GTA…5’
i) Applying your knowledge of palindrome sequences identify and mark the possible region where the restriction enzyme X will act.
ii) Restriction enzyme Y was used to extract gene of interest from a plant. This gene needs to be inserted in the given DNA segment which has been treated with restriction enzyme X. Will there be successful recombination? Explain with a reason.
c) Which one of the two (pUC18 and pBR322) would you prefer for biotechnological studies? Justify.
30. Observe the graph given below.
The graph represents inter-specific interaction between two species of Paramecia competing for the same resource in a culture medium. Paramecium caudatum and Paramecium aurelia were grown in separate cultures as well as in mixed cultures. It was found that each species grew in numbers according to the logistic equation.
a) Which species is competitively superior? Support it with the data provided in the graph.
b) State the underlying principle for the above result and name the scientist associated with this principle.
c) Explain the mechanism in which two or more species competing with each other can co-exist.
OR
Graphs A and B shown below depict the interaction of two species. Which graph indicates Mutualism? Give reason.
Class 12 Biology Sample Paper 2023-24 with Answers : Section E
Section E
(Each Question 5 Marks)
31 Placed below are case studies of some couples who were not able to have kids. These couples are not ready for adoption or taking gametes from donors. After thoroughly examining the cases, which Assisted Reproductive Technology will you suggest to these couples as a medical expert? Explain briefly the justification of each case.
OR
Given below are certain situations. Analyze the situation and suggest the name of a suitable contraceptive device along with the mode of action.
32. Given below is a stretch of DNA showing the coding strand of a structural gene of a transcription unit.
5’–ATG ACC GTA TTT TCT GTA GTG CCC GTA CTT CAG GCA
TAA—3’
a) Write the corresponding template strand and the mRNA strand that
will be transcribed, along with its polarity.
b) If GUA of the transcribed mRNA is an intron, depict the sequence
involved in the formation of mRNA /the mature processed hnRNA
strand.
i. In a bacterium
ii. In humans
c) Upon translation, how many amino acids will the resulting polypeptide
have? Justify.
OR
In shorthorn cattle, the coat colors red or white are controlled by a single pair of alleles. A calf that receives the allele for red coat from its mother and the allele for white coat from its father is called a ‘roan’. It has
an equal number of red and white hairs in its coat.
a) Is this an example of codominance or of incomplete dominance?
b) Give a reason for your answer.
c) With the help of genetic cross explain what will be the consequent phenotype of the calf when
i. red is dominant over white
ii. red is incompletely dominant.
33 Explain the role of Primary and Secondary Lymphoid organs with the help
of suitable examples.
OR
With the help of a flow chart illustrating how an infected animal cell can survive while viruses are being replicated or released.
Biology Model Question Paper 2024 Class 12
The Central Board of Secondary Education has also issued the CBSE Class 12 Biology Additional Model Question Paper. Solving these CBSE Class 12 Biology Additional Practice Questions with answers aids in understanding the question paper pattern and marking methodology. Students can access the CBSE Class 12 Biology Additional Practice Questions 2023-24 PDF, as well as the marking scheme and answer key, from the CBSE official website or this post.
Biology sample paper Class 12 2024 with Solutions
1. During the pollen grain formation, the generative cell divides to give rise to the two male gametes.
What is the ploidy of the generative cell?
(a) n
(b) 2n
(c) 3n
(d) 4n
Answer: (a) n
2. Kiwi is a dioecious species. Which of the following methods can be definitely RULED OUT as a possible mode of pollination in its case?
P) cleistogamous autogamy
Q) chasmogamous autogamy
R) geitonogamy
S) xenogamy
(a) only P and R
(b) only P and Q
(c) only Q and S
(d) only P, Q and R
Answer:(d) only P, Q and R
3. Arun thinks that identifying the exact mRNA sequence from the protein sequence is difficult.
Is he correct and why?
(a) No, as the genetic code is universal.
(b) Yes, as the genetic code is degenerate.
(c) No, as the mRNA is translated into a protein sequence.
(d) Yes, as the mRNA contains introns which are non-coding sequences.
Answer (b) Yes, as the genetic code is degenerate.
4. Crickets are insects that follow the XO type of sex determination. Which of the following statements is ALWAYS TRUE about this type of sex determination?
(a) Eggs that have an O chromosome will give rise to a male cricket.
(b) Eggs that have an X chromosome will give rise to a female cricket.
(c) Sperms that have an X chromosome will give rise to a male cricket.
(d) Sperms that have an O chromosome will give rise to a male cricket.
Answer: (d) Sperms that have an O chromosome will give rise to a male cricket.
5. Oysters are generally either dark or light in color. Dark oysters excel in dark environments, while light oysters thrive in bright environments. Intermediate-colored oysters are disadvantaged, lacking effective camouflage in either setting.
Which type of natural selection does this phenomenon exemplify?
(a) directional
(b) stabilising
(c) disruptive
(d) (The phenomenon described does not exemplify natural selection.)
Answer; (c) disruptive
6. A team of archaeologists found a fossilized skeleton of a human-like creature with a brain capacity of more than 700cc. The structure and its associated findings also show evidence that this creature could use tools for hunting.
Which stage of human evolution is this creature NOT from?
(a) Homo erectus
(b) Homo habilis
(c) Neanderthal Man
(d) Australopithecines
Answer: (d) Australopithecines
7. Which of the following is CORRECT about the movement of DNA on an agarose gel and the reason for it?
(a) P
(b) Q
(c) R
(d) S
Answer: (d) S
8. What is the MINIMUM possibility of a dominant trait being expressed in the offspring after a test cross?
(a) 25%
(b) 50%
(c) 75%
(d) 100%
Answer: (b) 50%
9. Which process is responsible for increasing the percentage of alcohol in Whisky after fermentation?
(a) malting
(b) dilution
(c) distillation
(d) maturation
Answer: (c) distillation
10. What do I in the restriction enzyme named ‘Hin S2 I’ indicate?
(a) It cuts after the first nucleotide in the restriction site.
(b) It is the first enzyme isolated from strain S2 of the bacterium.
(c) There is definitely more than one enzyme isolated from the same bacterium.
(d) There is only one enzyme that can be used to digest a plasmid from strain S2 for the bacterium.
Answer: (b) It is the first enzyme isolated from strain S2 of the bacterium.
11. Sumi and Nisha said the following about somatic hybridization in plants.
Sumi: Gametes are not required for hybridization.
Nisha: The resultant plant that grows after the fusion of the cells is genetically identical to the parent plants.
Who among them is/are CORRECT?
(a) only Sumi
(b) only Nisha
(c) both Sumi and Nisha
(d) neither Sumi nor Nisha
Answer: (a) only Sumi
12. Rupal says that in marine food chains where the pyramid of biomass is inverted, the 10% rule of energy transfer is not applicable.
Is she CORRECT and why?
(a) No, because every level still gets 10% of the energy from the lower level.
(b) Yes, because there are more consumers and so more energy is transferred.
(c) No, because the pyramid of biomass can never be inverted for any food chain.
(d) Yes, because there is a lower biomass of producers in these food chains so less energy is transferred.
Answer: (a) No, because every level still gets 10% of the energy from the lower level.
Question No. 13 to 16 consist of two statements – Assertion (A) and Reason (R). Answer these questions by selecting the appropriate option given below:
a) Both A and R are true and R is the correct explanation of A.
b) Both A and R are true and R is not the correct explanation of A.
c) A is true but R is false.
d) A is false but R is true.
13. Assertion (A): The coconut endosperm is multinucleate throughout its development.
Reason (R): Some endosperms undergo free nuclear division without the formation of distinct cell boundaries.
Answer: (a) Both A and R are true, and R is the correct explanation for A
14. Assertion (A): DNA ligase is not used in PCR.
Reason (R): Okazaki fragments are not formed in the amplification of DNA by PCR.
Answer:(a) Both A and R are true, and R is the correct explanation for A.
15. Assertion (A): To promote sustainability while minimizing waste, it is recommended to reuse needles up to two times for the same person.
Reason (R): Sterilisation of needles eliminates all pathogens and ensures safety.
Answer:(d) A is false, but R is true.
16. Assertion (A): Nuclear DNA extracted from a cell is visible to the naked eye but unstained plasmid DNA running in an agarose gel is not.
Reason (R): Plasmid DNA is transparent but nuclear DNA is not.
Answer:(c) A is true, but R is false.
Biology Model Question Paper 2024 with Answers PDF
Students can also learn about crucial exam themes by practicing with these Biology Practice Questions. The CBSE biology model question paper 2024 with answers pdf as well as the marking structure, was just released by the board. Students can now obtain the CBSE biology model question paper 2024 with answers pdf and marking scheme with Solution from the direct links provided below.
| CBSE Biology Model Question Paper 2024 with Answers PDF |
| CBSE Class 12 Biology Model Question Paper 2024 PDF |
| CBSE Class 12 Biology Model Question Paper 2024 with Solutions |
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