PSEB CLASS 11 BIOLOGY GUESS PAPER MARCH 2026 SET 1

PUNJAB SCHOOL EDUCATION BOARD

PSEB CLASS 11 BIOLOGY GUESS PAPER MARCH 2026

Max Marks: 70 Time allowed: 3 Hours

General Instructions:

1. Question paper will consist of four sections A, B, C and D with a total of 19 questions.
2. Section-A will contain question number 1 having 20 parts of 1 mark each. 12 questions will be of Multiple-choice question type, 4 fill in the blanks, 4 are True/False.
3. Section-B will contain questions number 2 to 11 (total 10 short answer type questions) of 2 marks each. Questions 4, 5, 9, 11 will have internal choice.
4. Section-C will contain questions number 12 to 16 (total 5 questions) of 3 marks each. Questions 12 and 15 will have internal choice.
5. Section-D will consist of questions 17 to 19 (total 3 questions) of 5 marks each. One choice question in each of question numbers 17 and 18 will necessarily be of a diagram/illustrative/graph-based question. One choice question in question number 19 will be a comprehension type question. All questions will have 100% internal choice.

SECTION - A (1 Mark Each)

1. Answer the following questions:

Multiple Choice Questions:
(i) Biological organisation starts with:
(a) Cellular level    (b) Organism level    (c) Atomic level    (d) Sub microscopic molecular level

(ii) Viruses are:
(a) Multicellular    (b) Unicellular    (c) Acellular    (d) Dead cell

(iii) The most advanced group in the plant kingdom is:
(a) Pteridophytes    (b) Gymnosperms    (c) Angiosperms    (d) Bryophytes

(iv) In sponges structure corresponding to mouth of other animals is:
(a) Osculum    (b) Ostium    (c) In current canal    (d) Excurrent canal

(v) The phenomenon where the ovary develops into a fruit without fertilization is called:
(a) Parthenocarpy    (b) Sexual reproduction    (c) Asexual reproduction    (d) None of the above

(vi) Casparian thickenings are found in the cells of:
(a) Pericycle of root    (b) Endodermis of root    (c) Pericycle of stem    (d) Endodermis of the stem

(vii) Which organelle is called power house of the cell?
(a) Golgi bodies    (b) Mitochondria    (c) Nucleus    (d) Plastids

(viii) DNA is a polymer of:
(a) Nucleotide    (b) Nucleoside    (c) Amino acids    (d) All of the above

(ix) Mitosis is also known as:
(a) Equational division    (b) Reductional division    (c) Multiplied division    (d) None of the above

(x) C4 pathway is also called as:
(a) Calvin cycle    (b) Hatch and Slack pathway    (c) Dicarboxylic acid pathway    (d) Both (b) & (c)

(xi) In which of the following processes CO2 is not released?
(a) Aerobic respiration in plants    (b) Aerobic respiration in animals    (c) Alcoholic fermentation    (d) Lactate fermentation

(xii) Full form of IAA is:
(a) Indole-3-acetic acid    (b) Indole-2-acetic acid    (c) Indole Acetic acid    (d) Indole Butyric acid

Fill in the blanks:
(xiii) ________ is a gaseous PGR.
(xiv) ________ is called the suicidal bag of the cell.
(xv) The outermost layer of porifera is called ________.
(xvi) The pH value of human urine is ________.

True / False:
(x7) The SA node is called the pacemaker of the heart.
(xviii) Left ventricle is the thickest chamber of the heart.
(xix) Duplication of DNA is called Replication.
(xx) Flatworms have true coelom.

SECTION - B (2 Marks Each)

2. What is the difference between Taxonomy and Systematics?

3. Differentiate between Notochord and nerve cord.

4. What is the function of companion cells in phloem?

OR

What are guard cells?

5. Give two identifying features of an adult male frog.

OR

Frog is poikilotherm, exhibits camouflage & undergoes aestivation and hibernation. How are these beneficial to it?

6. What is mesosome? Mention its functions.

7. Define the term “callus”.

8. Name the major site where RBCs are formed.

9. What are podocytes?

OR

What is GFR?

10. Name two natural, synthetic auxins.

11. List the functions of cerebrum.

OR

Define reflex actions. What is their significance?

SECTION - C (3 Marks Each)

12. What are the limitations of two kingdom system of classification?

OR

Write a note on reproduction in Fungi.

13. Draw a well labelled diagram of V.S. of maize seed.

14. Compare the structure and components of prokaryotic and eukaryotic cells.

15. Explain sigmoid growth curve with the help of a diagram.

OR

Describe the role of gibberellins in plant growth and development.

16. What physiological circumstances lead to erythroblastosis foetalis?

SECTION - D (5 Marks Each)

17. Explain how sexual reproduction in angiosperms takes place through double fertilization and triple fusion. Also draw a labelled diagram of embryo sac to explain the phenomena.

OR

Describe the alternation of generations in plants with a labelled diagram.

18. Explain the major steps in Krebs cycle. Why is this cycle called as citric acid cycle?

OR

Diagrammatic view of human respiratory system is given below. Identify A, B, C, D and E.
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19. Describe the different types of symmetry found in animals and give examples for each.

OR

Comprehension Question:
To escape the summer heat, Sharat made a sightseeing tour to Manali with his friends. After reaching the hill station, he felt dizziness, shortness of breath, and increased heart rate. One of Sharat’s friends, a medical student, told him that his was an acute mountain sickness. Read the above passage and answer the following questions:
(i) What is the cause of acute mountain sickness?
(ii) What is the treatment for this condition?
(iii) Which people should avoid high altitudes?

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