CBSE Class 11 Biology Term 1 Sample Paper 2025 with Solutions - Download PDF

The CBSE Class 11 Term I Question Paper for the academic year 2025-26 is a crucial tool for students getting ready for their mid-term tests. Sample papers are valuable tools for students to assess their comprehension of subjects and familiarize themselves with the final exam structure and potential question types. Through consistent practice, students can identify their strengths and areas requiring further attention. This helps them prepare better for the end term exam. The CBSE Class 11 Half Yearly Question Paper 2025-26 is an important resource for students preparing for their mid-term exams, typically held in September and October.

These sample papers are made by experts as an invaluable resource for students preparing for their Half Yearly exams. They offer a clear understanding of the exam pattern, highlight crucial topics, and familiarize students with potential question types. Students can easily access and download these papers, which serve as an excellent tool for self-assessment and revision. This article comprehensively covers all relevant topics and important questions, enabling students to practice and aim for high scores. After reviewing the questions, students can download the sample paper and its solutions in PDF format.

CBSE Class 11 Half Yearly Biology Sample Paper 2025

Section–A

1.In phylum arthropoda, excretion takes place through

(a) nephridia 

(b) flame cells 

(c) malphigian tubules 

(d) gills

2.Which of the following is a fresh water sponge?

(a) Spongilla

(b)Pleurobrachia

(c) Euspongia

(d) Sycon

3. Frogs show which type of excretion?

(a) Ureotelic

(b) Ammonotelic in water and ureotelic on land

(c)Ammonotelic

(d) Urecotelic

4. Select the correct statements:

(A) Platyhelminthes are triploblastic pseudocoelomate and bilaterally

symmetricalorganisms.

(B) Ctenophores reproduce only sexually and fertilization is external.

(C) In tapeworm, fertilization is internal but sexes are not separate.

(D) Ctenophores are exclusively marine, diploblastic and bioluminescent organisms.

(E) In sponges, fertilization is external and development is direct.

Choose the correct answer from the options given below:

(a) (A), (C) and (D) only

(b) (B), (C) and (D) only

(c) (A) and (E) only

(d) (B) and (D) only

5.Aestivation found in the members of family Solanaceae is:

(a) Valvate

(b) Vexillary

(c) Imbricate

(d) Twisted

6.One of the examples of the action of the autonomous nervous system is

(a) swallowing of food

(b) pupillary reflex

(c) peristalsis of the intestines

(d) knee-jerk response

7.The potential difference across resting membrane is negatively charged. This is due

to differential distribution of the following ions-

(a) Na+ and K+ ions

(b) CO3 ++ and Cl- ions

(c) Ca++ and Mg++ ions

(d) Ca++ and Cl- ions

8.Which out of the following statements is incorrect?

(a) Grana lamellae have both PS I and PS II

(b) Cyclic photophosphorylation involves both PS I and PS II

(c) Both ATP and NADPH + H+ are synthesised during non-cyclic

photophosphorylation.

(d) Stroma lamellae lack PS II and NADP reductase

9.Which among the five-kingdom system of classification do not possess nuclear

membrane?

(a)Monera

(b) Protista

(c) Fungi

(d) Plantae

Also Check - CBSE Class 11 Biology Diagrams for Quick Revision

10.We can produce a concentrated/diluted urine. This is facilitated by a special Mechanism . Identify the mechanism.

a) Re absorption from PCT

b) Reabsorption from collecting duct

c)Reabsorption/Secretion in DCT

d)Counter current mechanism in Henle’s loop/Vasa recta.

11.Identify in order the plants showing alternate , opposite and whorled phyllotaxy.

(a) China rose,Alstonia, Calotropis.

(b) Alstonia.Calotropis, china rose.

(c) Calotropis, Chinarose, Alstonia.

(d) China rose, Calotropis, Alstonia.

12.The part of brain located between the thalamus, hypothalamus of fore brain and pons

is known as-

(a) Mid-brain

(b) Hind-brain

(c) Limbic system

(d) All of these

Question 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: Photosynthetically C4 plants are less efficient than C3 plants.

Reason: The operation of C4 pathway reduces the loss caused by photorespiration.

14.Assertion: The flower is modified shoot meant for sexual reproduction.

Reason: Flowers are arranged in different types of inflorescences

15.Assertion (A): Carbohydrates are used first by most cells in respiration

Reason ( R): Lipids are never used in respiration

16.Assertion (A): Air sacs are connected to lungs in class –Aves

Reason (R) :They supplement respiration in birds

Section–B

17.Plant growth regulators (PGRs) have innumerable practical applications. Name the PGR you should use to

(i) Increase yield of sugarcane.

(ii) Promote lateral shoot growth.

(iii) Bolting in rosette plants.

Inhibit seed germination.

18.The mode of arrangements of sepals or petals in floral bud is known as aestivation.

Draw the various aestivation possible for a typical pentamerous flower.

Or

How are open vascular bundles different from closed vascular bundles.

19.Starch, cellulose, glycogen, chitin are polysaccharides found among the following.

Choose the one appropriate and write against each.

1. cotton fibre _

2. Exoskeleton of cockroach

3. liver_

4. Peeled potato_

20.How do ureters in male frog differ from that of female frog?

21.In modern medicine certain infectious neurological diseases were found to be transmitted by an agent consisting of abnormally folded protein. What are they called? Name one disease caused by the agent.

Section–C

22.“All enzymes are protein still some enzymes require a non-proteinaceous part for its

activity”- give a brief review on it.

23. What do you understand by the secondary, tertiary structure of a protein? Explain

with diagram.

24. Give an example for each of the following.

a) An organism possessing water-vascular system

b)A fish possessing a poison sting

c)A fish possessing an electric organ

d)An organ, which regulate buoyancy

e)An animal, which exhibits alternation of generation.

F) Name one flightless birds.

25.i) Why S-A Node is called the pace maker of heart?

ii) What are heart sounds? How and when they are produced?

OR

With respect to various lung volumes explain i) Vital capacity ii) residual volume iii)

tidal volume.

26.Draw illustrations to bring out the anatomical difference between Monocot stem and Dicot stem.

27.Explain the gametophytic and sporophytic stages in Funaria with labelled diagram only.

28.What are the three major steps of urine formation? Explain in brief.

Section D

Q. No. 29 and 30 are case-based questions. Each question has 3 subparts with internal choice in one subpart.

29.Read the given passage and answer the questions that follows. each question hassubparts with internal choice in one. In pteridophytes, the main plant body is a sporophyte which is differentiated into tree, root and leaves. These organs possess well differentiated vascular tissues.

1)What is sporophylls?

2)Name any two species of pteridophytes which show heterosporous.

3)Name the male and female sex organs of pteridophytes.

OR

What are the two events that are considered as precursors of seed habit?

30. Pancreas is a composite gland which acts as both exocrine and endocrine gland. The endocrine pancreas consists of Islets of Langerhans. The two main types of cells in the Islet of Langerhans are called α cells and β cells. The α cells secrete a hormone called glucagon while β cells secrete insulin.

1.Which endocrine gland and its part is involved in the secretion of insulin? 

2.What is the role of insulin in controlling level of glucose in blood?

3.What is hypo glycaemia?

OR

Justify glucagon is a hyperglycemic hormone?

Section–E

31.(i) What do you understand by oxidative phosphorylation? Where does it occur

inside the cell? Name the enzyme responsible for this reaction. 3

(ii) List two ways by which molecules of ATP are produced in glycolysis during

aerobic respiration in a cell.

32.Represent schematically the Calvin cycle & explain the process.

OR

Describe Z – scheme of light reaction along with figure. Why it is called non-cyclic

photophosphorylation also?

33.What are the various stages of meiotic prophase I? Enumerate the chromosomal

events during each stage?

OR

a)Comment on the statement –Telophase is reverse of prophase?

b)Why is mitosis called equational division?

Also Check - CBSE Class 11 Biology Syllabus