HBSE Class 12th Biology Question Paper 2025 With Answer Key: FREE PDF Download

HBSE Class 12th Biology Question Paper 2025: Are you also looking for the question paper of Haryana Board Class 10th Hindi? Well, don’t worry as we have got you covered. Check this article to get the Haryana Board class 12th Biology question paper with answer key for free. Also, download the pdf for free. 

HBSE Class 12th Biology Exam 2025: Highlights

In this table, we are providing the key highlights of the Haryana Board Class 12th Biology exam. 

Haryana Board HBSE Class 12th Biology Question Paper 2025

Below is the provided set for HBSE Class 12th Biology Question Paper 2025. 

HBSE Class 12th Biology Question Paper Download PDF

HBSE Class 12th Biology Answer Key 2025

Below are the answers for Haryana Board Class 12th Biology Answer Key.

Here are the multiple-choice questions with their correct answers:

1. The cause of sickle cell anemia is:
   (A) Point mutation
   (B) Natural selection
   (C) Adaptive radiation
   (D) Both (B) and (C)
2. इनमें से किस उत्पाद का औद्योगिक उत्पादन Saccharomyces cerevisiae की उपस्थिति से नकारात्मक रूप से प्रभावित हो सकता है?
   (A) बीयर
   (B) वाइन
   (C) फलों का रस
   (D) गेहूँ की रोटी 
3. An individual infected with a fungal disease shows dry scaly lesions on various body parts. Which of the following diseases might it be?
   (A) Ringworm
   (B) Filariasis
   (C) Amoebiasis
   (D) Ascariasis
4. A carbon sink is any environment that can store carbon and remove it from the atmosphere. Which of the following will lead to a decline in the carbon sink?
   (A) Deforestation
   (B) Population growth
   (C) Burning of fossil fuels
   (D) Increase in industrial activity
5. पुष्पी पौधों में गुणसूत्रों की संख्यागत क्या है?
   (A) 2n
   (B) 3n
   (C) 4n
   (D) 6n
6. What happens to the BOD of a water body with the removal of effluents from it?
   (A) Increases
   (B) Decreases
   (C) Remains the same
   (D) Increases and then stagnates
7. The distance between the two strands of a DNA molecule ............ from one end to another.
   (A) Increases
   (B) Remains the same
   (C) Decreases
   (D) None of these
8. काले अखरोट का पौधा जुगलोन नामक एक रासायनिक पदार्थ स्रावित करता है जो अपने जड़ वाले काली मिर्च जैसे अन्य पौधों को नष्ट कर देता है, यह प्रतिस्पर्धा की किस प्रकार की पारस्परिक क्रिया दर्शाता है?
   (A) परभक्षण (Predation)
   (B) प्रतिस्पर्धा (Competition)
   (C) सहजीविता (Mutualism)
   (D) अंजरजीवीय परजीविता (Endoparasitism)
9. Ginkgo biloba is known as a living fossil as it has changed very little over time, is resistant to disease and pests, is tolerant of a wide range of environmental conditions, and is the last standing member of its botanical family. It is an example of which of the following phenomena?

(A) Speciation
(B) Fossilization
(C) Adaptive radiation
(D) Survival of the fittest

10. At what organism level in this food chain the concentration of BFRs (Brominated Flame Retardants) is highest?

Answer: Humans (since biomagnification leads to the highest concentration at the top of the food chain).

11. What kind of charge is present on a DNA molecule?

Answer: Negative charge (due to the phosphate backbone).

12. In PCR reaction at Step-2, denaturation of DNA takes place. Name the responsible factor for it.

Answer: Heat (denaturation occurs at around 94-98°C).

13. The non-coding sequences are called __________.

Answer: Introns.

14. __________ are called molecular scissors.

Answer: Restriction enzymes (or Endonucleases).

15. Energy is always highest at the first trophic level and reduces as we move up the 

Answer: Trophic levels (because of energy loss due to heat and metabolism).

Question 16:

Assertion (A):

"Health does not simply mean 'absence of disease' or 'physical fitness'." True

Reason (R):

"Health is defined as a state of complete physical, mental, and social well-being." True

Since Reason (R) correctly explains Assertion (A), the correct answer is:

(A) Assertion (A) and Reason (R) both are true and Reason (R) is the correct explanation of Assertion (A).

Question 17:

Assertion (A):

"Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA) are two types of nucleic acids found in living systems." True

Reason (R):

"RNA acts as the genetic material in most of the organisms."  False

Explanation:

• While RNA does serve as the genetic material in some viruses (like retroviruses), DNA is the primary genetic material in most organisms.
• Since Reason (R) is false but Assertion (A) is true, the correct answer is:

(C) Assertion (A) is true, but Reason (R) is false.

Question 18:

Assertion (A):

"Tropics have greater biological diversity." True

Reason (R):

"There is most solar energy available in tropics which contributes to higher productivity." True

Explanation:

• The tropics receive the highest amount of solar energy, which supports high primary productivity.
• This leads to richer ecosystems and greater biodiversity.
• Since Reason (R) correctly explains Assertion (A), the correct answer is:

(A) Assertion (A) and Reason (R) both are true, and Reason (R) is the correct explanation of Assertion (A).

Very Short Answer Type Questions from Section B:

19. Differentiate between Transcription and Translation:

• Transcription: The process of copying genetic information from DNA to mRNA.
• Translation: The process where ribosomes synthesize proteins using the mRNA sequence.

20. What are auto-immune diseases? Give one example.

• Auto-immune disease: A condition where the immune system mistakenly attacks the body's own cells.
• Example: Rheumatoid arthritis, Type 1 diabetes, Lupus.

21. What is Totipotency?

• Totipotency: The ability of a single cell to develop into an entire organism under suitable conditions.

22. Differentiate between Immigration and Emigration:

• Immigration: The movement of individuals into a population from another location.
• Emigration: The movement of individuals out of a population to another location.

23. What is allergy? Give one example.

• Allergy: A hypersensitive reaction of the immune system to certain substances (allergens) like pollen, dust, or food.
• Example: Hay fever (allergic rhinitis), Asthma, Skin rashes.

Alternative Question: What is immunity? Name its types.

• Immunity: The body's defense mechanism against infections and diseases.
• Types of Immunity:
1. Innate immunity (natural, non-specific) 2. Adaptive immunity (acquired, specific)

 Also Check:

• Haryana Board HBSE Class 10 Syllabus 2024-25
• HBSE Class 10 Syllabus 2024-25
• HBSE Class 12th Syllabus 2024-25
• Haryana Board Class 10 Model Papers 2024-25
• Haryana Board Class 12 Model Papers 2024-25