CBSE Class 12 Biology Practice Paper 2023, Download PDF

CBSE Class 12 Biology Practice Paper 2023: Download the practice paper of CBSE class 12th Biology in PDF to practice important questions for the upcoming CBSE Class 12 Biology Board Exam 2023. Also, check the marking scheme to get solutions to all questions in the practice paper.

CBSE Class 12 Biology Practice Paper 2023: CBSE Class 12 Biology Board Exam 2023 is scheduled to be conducted on Thursday, March 16, 2023. It is an important paper for students who are planning to pursue their university-level education in medicine, healthcare and allied fields. Moreover, as it is a core subject in the Science stream, it is important for students to score well in CBSE Class 12 Biology board exam 2023 to get good overall results. Therefore, students preparing for the Biology exam on Thursday, 16th March will find this practice paper or additional practice questions very beneficial in their preparation for the board exam. 

CBSE Class 12 Biology Question Paper Structure

The exam will be conducted for 80 marks.

15 minutes will be allotted to students for reading the questions.

3 hours of time is given for students to attempt the paper. 

Section–A will have 16 questions of 1 mark each 

Section–B will have 5 questions of 2 marks each

Section– C will have 7 questions of 3 marks each 

Section– D will have 2 case-based questions of 4 marks each

Section–E will have 3 questions of 5 marks each. 

CBSE Class 12 Biology Practice Paper 2023

SECTION A

1 Birth control tablets in females, popularly referred to as pills, prevent pregnancy by __________.

• A. delaying menstruation
• B. inhibiting ovulation and implantation
• C. suppressing sperm motility and fertility
• D. blocking the entry of sperms during coitus

2 Which of the following statements is/are correct about ZIFT and GIFT as methods of helping conception in cases of infertility?

P) ZIFT can help where the female is unable to form a viable ovum.

Q) ZIFT uses methods of in vitro fertilisation.

R) GIFT involves the injection of one’s own ovum into the body.

S) GIFT uses in vivo fertilisation method.

A. only P

B. only P and R

C. only Q, R and S

D. all – P, Q, R and S

3 A DNA sequence consisted of 20% adenine nucleotides. What would be the percentage of cytosine nucleotides in the same DNA sequence?

20%

30%

60%

80%

4 Comparative anatomy and morphology studies deepened the understanding of evolution. The presence of analogous and homologous structures provides important evidence in the favour of evolution. Which of the following is/are examples of HOMOLOGOUS structures found in plants?

1. only Q
2. only R
3. only P and Q
4. only Q and R

5 In certain diseased conditions such as pneumonia, the fingernails of an individual turn blue. What could be the reason for this?

1. blood does not reach fingernails due to an increase in fat content around the fingernails
2. nails become cold due to a decrease in fat content around the fingernails
3. reduced levels of oxygen in the blood
4. increase in oxygen levels in the blood

6 In which of the following diseases is/are the parasites transmitted to a healthy individual through the bite of a female mosquito?

P) malaria

Q) ascariasis

R) filariasis

1. only P
2. only P and Q
3. only P and R
4. all – P, Q and R

7 A substrate is the surface on which an organism lives or survives on. Which of the following acts as the substrate that provides energy in a detritus food chain?

1. sunlight
2. green plants
3. decomposers
4. dead organic matter

8 Given below are two statements about polymerase chain reactions.

P) It mimics DNA replication that happens in a cell.

Q) It cannot be used to amplify RNA molecules.

Which of these is/are TRUE?

1. only P
2. only Q
3. both P and Q
4. neither P nor Q

9 Given below is a food web representative of the Arctic region.

Increasing temperatures have been causing changes in the ocean ecosystem. These changes have caused the population of Arctic cod to decline rapidly.

Which of the following statement/s is/are most likely to be TRUE based on this information?

P) The population of arctic birds will increase.

Q) The ringed seal will slowly become extinct.

R) The harbour seal will be dependent on capelins alone.

1. only P
2. only R
3. only Q and R
4. all – P, Q and R

10 In which of the following is competition MOST LIKELY to occur?

P) related species in the same environment

Q) related species in different environments

R) unrelated species in the same environment

S) unrelated species in different environments

1. only P and Q
2. only P and R
3. only Q and S
4. only P, Q and R

11 Which of the following is most likely to be true about the percentage of energy received by a horse and a crow from the producers in different food chains?

1. P
2. Q
3. R
4. S

12 A stable community is usually resistant to invasion by alien species. Which of the following would NOT be affected in a stable community due to this resistance?

1. species richness
2. productivity
3. co-extinction
4. total biomass

Question No. 13 to 16 consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true and R is not the correct explanation of A.
3. A is true but R is false.
4. A is False but R is true.

13 Assertion (A): Apomixis and parthenocarpy are both asexual modes of reproduction.

Reason (R): Seeds are not produced in both apomixis and parthenocarpy.

14 Assertion (A): A colour-blind father will always have a colour-blind son.

Reason (R): Genes causing colour blindness are passed through a sex chromosome.

15 Assertion (A): Gene therapy is a method of treating a disorder but cannot cure it.

Reason (R): Cells are drawn from a patient and the functional gene is introduced into

these cells and transferred back to the patient.

16 Assertion (A): In the absence of a predator, the prey population growth will always

be exponential.

Reason (R): Exponential growth is when the resources and the environment allow an

organism to realise fully its innate potential to grow in numbers.

SECTION B

17 Given below is the karyotype of an individual.

(a) What are the characteristic reproductive and physical features of such an individual?

(b) What is the category of such disorders called? How is it caused?

To view the complete practice question paper, click on the link below:

To view the solutions to CBSE Class 12 Additional Practice Question Paper, click on the link below:

Important Links for CBSE Class 12 Biology Board Exam 2023

ALSO VISIT:

The rationalised syllabus of CBSE Class 12 for 2022-23

The list of deleted topics from CBSE Class 12 syllabus 2022-23

The sample question paper and marking scheme for CBSE Class 12 2022-23

Other Important Links for CBSE Class 12 Board Exam 2023