General Instructions
1. This question paper consists of three sections: Section A, Section B and Section C.
2. All questions are compulsory.
3. Section A has 16 questions.
4. Section B has 13 questions.
5. Section C has 10 questions.
6. Internal choices are given in some questions, as indicated.
ABIOLOGY
1
Which of the following organelles is responsible for generating most of the cell's supply of adenosine triphosphate (ATP), used as a source of chemical energy?(a) Nucleus(b) Ribosome(c) Mitochondrion(d) Endoplasmic Reticulum
2
Which tissue in plants is responsible for the transport of water and minerals from the roots to the leaves?(a) Phloem(b) Epidermis(c) Parenchyma(d) Xylem
3
A student observes a cell under a microscope and notes that it has a cell wall, chloroplasts, and a large central vacuole. Which type of cell is it most likely to be?(a) Animal cell(b) Bacterial cell(c) Plant cell(d) Fungal cell
4
Identify the process shown in the diagram:[Diagram showing a pollen grain landing on the stigma, then a pollen tube growing down to the ovary](a) Germination(b) Fertilisation(c) Pollination(d) Transpiration
5
The process by which new cells are formed from pre-existing cells is called:(a) Photosynthesis(b) Respiration(c) Cell division(d) Transpiration
6
Which of the following is a characteristic feature of vascular plants (Pteridophytes)?(a) They depend on water for reproduction.(b) They have true roots, stems, and leaves.(c) They produce flowers and fruits.(d) They are unicellular.
7
The Biosphere is best described as:(a) All the living organisms and their habitats.(b) All the water bodies on Earth.(c) The solid crust of the Earth.(d) The gaseous envelope surrounding the Earth.
8
Assertion (A): In multicellular organisms, cells are organised into tissues.Reason (R): Tissues are groups of similar cells specialised to perform a specific function, leading to division of labour.(a) Both A and R are true, and R is the correct explanation of A.(b) Both A and R are true, but R is not the correct explanation of A.(c) A is true, but R is false.(d) A is false, but R is true.
9
Assertion (A): The nucleus is often called the 'brain' of the cell.Reason (R): The nucleus controls all the activities of the cell and contains genetic material.(a) Both A and R are true, and R is the correct explanation of A.(b) Both A and R are true, but R is not the correct explanation of A.(c) A is true, but R is false.(d) A is false, but R is true.
10
Briefly explain the function of lysosomes in a cell.
11
Distinguish between meristematic and permanent tissues in plants.
12
Explain the process of fertilisation in flowering plants.
13
A group of students is studying plant diversity. They observe a plant that has vascular tissues (xylem and phloem) for water and food transport, true roots, stems, and leaves, but reproduces via spores and requires water for fertilisation.(a) Which group of plants are they most likely observing?(b) Name one characteristic that distinguishes this group from Angiosperms.
14
Explain the concept of asexual reproduction and give two examples in plants.
15
Case Study: The Indian subcontinent experiences monsoon winds, which bring heavy rainfall crucial for agriculture. This phenomenon is driven by the differential heating of land and sea.(a) Explain why land heats up faster than the sea.(b) How does this differential heating lead to the formation of monsoon winds?(c) Name two spheres of the Earth that are significantly impacted by monsoon rains.
16
Long Answer: Describe the structure and function of a neuron. OR Explain the process of osmosis with the help of an activity.
BCHEMISTRY
17
Which of the following is an example of a heterogeneous mixture?(a) Salt solution(b) Air(c) Milk(d) Muddy water
18
The symbol for Sodium is:(a) S(b) So(c) Na(d) Sn
19
Which law states that atoms cannot be created or destroyed in a chemical reaction?(a) Law of Definite Proportions(b) Law of Conservation of Mass(c) Dalton's Atomic Theory(d) Law of Multiple Proportions
20
State the postulates of Dalton's Atomic Theory.
21
Differentiate between a compound and a mixture.
22
Explain the formation of a covalent bond using the example of a water molecule ().
23
Case Study: A student adds a white solid to water in a beaker and observes that the solid dissolves completely, forming a clear solution. When a beam of light is passed through the solution, the path of the light is not visible. The student then adds a few drops of milk to the solution, and the path of the light beam becomes visible.(a) What type of mixture was initially formed when the solid dissolved in water?(b) What type of mixture is formed when milk is added to the solution?(c) What phenomenon is being demonstrated here?(d) Explain why the path of light was not visible in the initial solution.
24
Long Answer:(a) Describe the process of distillation for separating a mixture of two liquids with different boiling points. (3 marks)(b) State the principle on which crystallization is based. (2 marks)OR(a) Explain how ions are formed from atoms. Illustrate with the formation of and ions. (3 marks)(b) Write the chemical formula of magnesium chloride and calcium nitrate. 2marks
CPHYSICS
25
A car travels a distance of 100 km in 2 hours. What is its average speed?(a) 50 km/h(b) 100 km/h(c) 200 km/h(d) 25 km/h
26
When a force of 10 N acts on an object of mass 5 kg, the acceleration produced is:(a) 0.5 m/s²(b) 2 m/s²(c) 50 m/s²(d) 15 m/s²
27
Assertion (A): The inertia of an object depends on its mass.Reason (R): An object with larger mass has more inertia.(a) Both A and R are true, and R is the correct explanation of A.(b) Both A and R are true, but R is not the correct explanation of A.(c) A is true, but R is false.(d) A is false, but R is true.
28
What is the difference between speed and velocity?
29
Explain the concept of work done by a force. Under what conditions is the work done zero?
30
A body is moving with a constant velocity. What can you say about the net force acting on it? Explain with reference to Newton's laws of motion.
31
(a) Derive the equation from a velocity-time graph. 3marks(b) What does the slope of a velocity-time graph represent? (1 mark)
32
Case Study: An athlete runs on a circular track of radius 50 m. He completes one full round in 2 minutes.(a) Calculate the total distance covered by the athlete in one round.(b) Calculate the displacement of the athlete after one round.(c) What is the athlete's average speed after one round?(d) What is the athlete's average velocity after one round?
33
Long Answer:(a) State Newton's third law of motion and illustrate it with an example. (3 marks)(b) Explain the concept of impulse. (2 marks)OR(a) Describe the energy transformation that takes place when a ball is thrown vertically upwards and then falls back to the ground. (3 marks)(b) What is meant by the conservation of mechanical energy? 2marks
Answer Key
ABIOLOGY
1
(c) Mitochondrion
2
(d) Xylem
3
(c) Plant cell
4
(c) Pollination
5
(c) Cell division
6
(b) They have true roots, stems, and leaves.
7
(a) All the living organisms and their habitats.
8
(a) Both A and R are true, and R is the correct explanation of A.
9
(a) Both A and R are true, and R is the correct explanation of A.
10
Lysosomes are membrane-bound organelles containing digestive enzymes. They are responsible for breaking down waste materials and cellular debris, as well as old or damaged organelles. They also play a role in defence against invading microorganisms.
11
Meristematic tissues: Actively dividing cells, thin cell walls, dense cytoplasm, generally absent vacuoles, responsible for growth in length and girth. Permanent tissues: Cells have lost the ability to divide, may have thickened cell walls, present as simple or complex tissues, provide support, protection, and conduction.
12
Fertilisation is the fusion of male gamete (present in pollen grain) with the female gamete (egg cell) inside the ovule to form a zygote. This is usually preceded by pollination and the growth of a pollen tube from the pollen grain to the ovule.
13
(a) Pteridophytes (Ferns). (b) Pteridophytes reproduce via spores, whereas Angiosperms reproduce via flowers and fruits.
14
Asexual reproduction is a mode of reproduction in which new individuals are produced from a single parent without the involvement of gametes. Examples: Vegetative propagation (e.g., potato tubers, ginger rhizomes, Bryophyllum leaf plantlets), budding (e.g., yeast), binary fission (e.g., Amoeba).
15
(a) Land has a lower specific heat capacity than water, so it heats up faster when exposed to solar radiation. (b) During summer, land heats up more than the sea, creating a low-pressure area over land. Cooler, high-pressure air from the sea moves towards the low-pressure area over land, resulting in monsoon winds. (c) Biosphere and Hydrosphere.
16
Neuron (Nerve cell): Structure - Cell body (containing nucleus and cytoplasm), dendrites (branch-like extensions that receive signals), axon (a long fibre that transmits signals away from the cell body). Function - To receive, process, and transmit electrical and chemical signals from one part of the body to another, enabling communication and coordination.OROsmosis Activity: Take two potato halves. Place one in plain water and the other in a concentrated salt solution. Observe the changes in the potato pieces over time. The piece in plain water will swell (absorb water), while the piece in salt solution will shrink (lose water). This demonstrates the movement of water across a semi-permeable membrane from a region of higher water concentration to a region of lower water concentration.
BCHEMISTRY
17
(d) Muddy water
18
(c) Na
19
(b) Law of Conservation of Mass
20
Postulates of Dalton's Atomic Theory:
- All matter is made up of tiny indivisible particles called atoms.
- Atoms of a given element are identical in mass and chemical properties.
- Atoms of different elements have different masses and chemical properties.
- Atoms combine in the ratio of simple whole numbers to form compounds.
- Atoms can neither be created nor destroyed in a chemical reaction.
21. Compound: A substance formed when two or more elements are chemically combined in a fixed ratio. Its properties are different from its constituent elements. Mixture: A substance formed when two or more substances are physically mixed in any proportion. Its properties are a combination of the properties of its constituents.
22. A water molecule () is formed by covalent bonding. Each hydrogen atom shares one electron with the oxygen atom, and the oxygen atom shares one electron with each of the two hydrogen atoms. This sharing of electrons forms covalent bonds, resulting in a stable molecule.
23. (a) True solution. (b) Colloidal solution. (c) Tyndall effect. (d) In a true solution, the solute particles are too small (ions or molecules) to scatter light. The path of light passes through without being visible.
24. (a) Distillation: This process is used to separate liquids with different boiling points. The mixture is heated, and the liquid with the lower boiling point vaporizes first. The vapor is then cooled in a condenser and collected as a pure liquid (distillate). The liquid with the higher boiling point remains in the distillation flask. (b) Crystallization: Based on the difference in solubility of a substance at different temperatures.
OR
(a) Ions are formed when atoms gain or lose electrons to achieve a stable electronic configuration (usually an octet). When an atom loses an electron, it becomes a positively charged ion (cation). When an atom gains an electron, it becomes a negatively charged ion (anion). Formation of : Sodium atom (Na, atomic number 11) has electronic configuration 2, 8, 1. It loses one electron to form (2, 8). Formation of : Chlorine atom (Cl, atomic number 17) has electronic configuration 2, 8, 7. It gains one electron to form (2, 8, 8). (b) Magnesium chloride: . Calcium nitrate: .
CPHYSICS
25
(a) 50 km/h
26
(b) 2 m/s²
27
(a) Both A and R are true, and R is the correct explanation of A.
28
Speed is the rate of change of distance, and it is a scalar quantity (magnitude only). Velocity is the rate of change of displacement, and it is a vector quantity (magnitude and direction).
29
Work done by a force is defined as the product of the magnitude of the force and the displacement of the object in the direction of the force (). Work done is zero when: (i) The force is zero. (ii) The displacement is zero. (iii) The force is perpendicular to the direction of displacement ().
30
If a body is moving with a constant velocity, the net force acting on it is zero. According to Newton's first law of motion, an object in motion continues in motion with constant velocity unless acted upon by a net external force. Newton's second law () also implies that if acceleration (a) is zero (due to constant velocity), then the net force () must be zero.
31
(a) Consider a velocity-time graph where the initial velocity is u, the final velocity is v, and the time taken is t. The graph is a straight line with a constant slope, representing constant acceleration. The acceleration is given by the slope: . Rearranging this equation gives . (b) The slope of a velocity-time graph represents acceleration.
32
(a) Distance = Circumference of the circular track = . (b) Displacement = 0 m (since the athlete returns to the starting point). (c) Average speed = Total distance / Total time = . (d) Average velocity = Total displacement / Total time = 0 m / 120 s = 0 m/s.
33
(a) Newton's third law of motion states that for every action, there is an equal and opposite reaction. Example: When you push a wall, the wall exerts an equal and opposite force on you. When a rocket expels gases downwards, the gases exert an equal and opposite force upwards on the rocket, propelling it forward. (b) Impulse is the change in momentum of an object. It is equal to the product of the average force acting on an object and the time interval over which the force acts ().OR(a) When a ball is thrown vertically upwards, its kinetic energy is converted into potential energy as it rises, reaching maximum potential energy and zero kinetic energy at its highest point. As it falls back, the potential energy is converted back into kinetic energy, reaching maximum kinetic energy and minimum potential energy just before hitting the ground. (b) Conservation of mechanical energy states that if the only forces acting on a system are conservative forces (like gravity), then the total mechanical energy (sum of kinetic and potential energy) of the system remains constant.
