Science 31/5/2 2025-2026 English Medium Class 10 Question Paper Solution

In human beings, the implantation of fertilised egg takes place in which part of female reproductive system?

Oviduct

Cervix

Uterus

Vagina

Yeast multiplies by which of the following methods?

Fragmentation

Binary Fission

Multiple Fission

Budding

Identify the part that controls the closing and opening of the stomatal pore in leaves of plants.

Select the correct option.

Stomata

Epidermal cells

Guard cells

Chloroplasts

Choose the equation of reaction that correctly represents anaerobic respiration in muscles:

\[\ce{Glucose -> Pyruvate ->[Absence][of O2] Ethanol + CO2 + Energy}\]

\[\ce{Glucose ->[O2] Pyruvate ->[O2] Energy}\]

\[\ce{Glucose ->[O2] Pyruvate ->[Lack of][oxygen] Ethanol + Energy}\]

\[\ce{Glucose -> Pyruvate ->[Lack of][oxygen] Lactic acid + Energy}\]

Which of the following is a non-biodegradable pollutant?

Paper

DDT

Wood

Vegetable peel

When a human egg is fertilized by a sperm having ‘Y’ chromosome, the zygote has the following combination of chromosomes:

44 + XX

22 + XX

44 + XY

22 + XY

The reasons for excessive generation of wastes are:

1. Use and throw policy.
2. Increased availability of packaged food.
3. Increased construction wastes.
4. Non-sorting of dry and wet wastes.

(i), (iii) and (iv)

(i), (ii) and (iii)

(i), (ii), (iii) and (iv)

(ii), (iii) and (iv)

Assertion (A): The peristaltic movements occur all along the gut.

Reason (R): The lining of the gut has muscles that contract rhythmically to push the food in regulated manner.

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

Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).

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

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

Assertion (A): Bacteria produced as a result of asexual reproduction would be similar.

Reason (R): There would be only minor differences between the bacteria generated due to small inaccuracies in DNA replication.

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

Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).

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

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

Observe the given figure and identify the labelled parts P, Q, R and S:

Which of the plant hormone is responsible for the following process?

Promote cell division

Which of the plant hormone is responsible for the following process?

Inhibition of growth

Which of the plant hormone is responsible for the following process?

Detection of light

Which plant hormone is responsible for the wilting and falling of leaves?

Briefly mention the steps in double-circulation through human heart.

Given below is a diagrammatic representation of cross-section of a leaf:

1. Identify ‘P’ in the given diagram and write down its role in plants.
2. Write down a balanced equation of process of photo-synthesis.

Write two harmful effects of using plastic bags on the environment.

Suggest better alternatives to the usage of plastic bags.

Paddy fields require a large amount of water. The pesticides and chemical fertilizers used are washed down into the soil or waterbodies. How do these chemicals reach our bodies? What is this phenomenon known as?

Name the hormone secreted in scary situations by animals.

Name the hormone secreted in scary situations by animals.

Write any three responses which enable the animal body to deal with a scary situation.

(a) Write the structure and function of Bowman’s capsule.    [1]

(b) Although kidneys filter a large amount (about 180 L daily) of fluids, still the excretion from the body is only about a litre or two. Why?    [1]

(c) What is excretion? Why is it necessary for any living organism?    [2]

OR

(c) State two similarities between lungs and kidneys.    [2]

1. Sugarcane does not produce seeds so name the process through which it will be able to reproduce.
2. List any two advantages of this method.
3. Besides sugarcane, give two more examples of plants that reproduce by this method.
4. Why regeneration is not possible in all the types of animals?

In an angiospermic flower, fertilization is said to take place when male gametes carried in the pollen tube fuse with the female gamete, present in the embryo sac. This results in lot of changes in different parts of the flower. State the changes taking place in the following structures of flower post fertilization:

1. Zygote
2. Ovule
3. Ovary
4. Sepals

Define the following:

Germination

Which of the following set of compounds does not belong to same homologous series?

CH₄ and C₄H₁₀

C₂H₆ and C₃H₈

C₃H₈ and C₅H₁₂

C₄H₈ and C₅H₁₂

Which of the following is an amphoteric oxide?

Na₂O

K₂O

CO₂

Al₂O₃

In the following diagram, if acetic acid of same concentration is taken in place of dilute sulphuric acid, then:

Same amount of H₂ gas will be evolved.

H₂ gas will not be evolved.

The amount of H₂ gas evolved in less amount.

In place of H₂ gas, O₂ gas will be evolved.

The volume ratio of hydrogen and oxygen gases liberated during electrolysis of water is ______.

1 : 2

2 : 1

1 : 3

4 : 1

Study the following table and select the correct option:

Which of the following will not undergo addition reaction?

C₄H₈

C₂H₂

C₃H₈

C₂H₄

On reaction with dilute HCl, which of the following pair of metals will evolve hydrogen gas?

copper and zinc

copper and iron

silver and magnesium

magnesium and aluminium

Assertion (A): Reaction of quick lime with water is an exothermic reaction.

Reason (R): A large amount of heat is evolved on the reaction quick lime and water.

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

Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).

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

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

How is a universal indicator obtained? How is the wide range of pH of solution tested by it?

What happens when calcium carbonate is heated? Write a balanced chemical equation of the reactions involved in support of your answer.

What happens when silver bromide is exposed to sunlight? Write balanced chemical equations of the reaction involved in support of your answer.

What happens when lead is added to copper (II) chloride solution? Write a balanced chemical equation of the reactions involved in support of your answer.

Give the chemical name of Plaster of Paris.

Give the formula of Plaster of Paris.

Write the preparation of the following compound with balanced chemical equation:

Plaster of Paris

Mention the uses of Plaster of Paris.

Name the acid present in ant’s sting.

Give reason:

While diluting an acid, it is recommended that the acid should be added to water.

Give reason:

Baking soda is used as an antacid.

(a) Write structural formula and name of 4^th member of alcohol homologous series.    [1]

(b) What happens when ethanol is heated with alkaline KMnO₄? Write chemical equation involved.    [1]

(c) Write the chemical equation of reaction of ethanol with ethanoic acid in the presence of concentrated H₂SO₄. Write the name of this reaction.    [2]

OR

(c) What happens when ethanol is heated with excess concentrated sulphuric acid at 443 K? Write chemical equation involved. What is the role of concentrated sulphuric acid in this reaction?    [2]

Give reasons for the following:

Ionic compound have generally high melting points and boiling points.

Give reasons for the following:

Solder, an alloy of lead and tin, is used for welding electrical wires.

Give reasons for the following:

Carbon cannot reduce the oxides of Na or Mg.

The reaction of compound ‘X’ with aluminium is used to join railway tracks:

1. Identify the compound ‘X’.
2. Name the reaction.
3. Write the balanced chemical equation of the reaction of compound ‘X’ with aluminium.

Write the balanced chemical equations when a mixture of Cu₂O and Cu₂S is heated.

Write the balanced chemical equations when ZnS is heated in the presence of oxygen.

Give reasons for the following:

The wires carrying current in homes have a coating of PVC.

Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).

Show the formation of ionic compound CaO with electron dot structure.

[Atomic number: Ca = 20, O = 8]

To restore clear vision in persons whose size of the eye ball has reduced, he/she is suggested to use suitable ______.

Converging lens

Diverging lens

Bifocal lens

Cylindrical lens

Rays from the sun converge at a point 25 cm behind a convex lens. The distance at which an object be placed in front of the lens to get a virtual image, is ______.

20 cm

40 cm

50 cm

More than 50 cm

Assertion (A): The needle of a compass, kept in an external magnetic field, always aligns itself in the North-South direction of the Earth. 

Reason (R): The behaviour of the needle of the compass is similar to the behaviour of a freely suspended bar magnet.

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

Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).

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

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

Arrange these material mediums given in the table in increasing order of speed of light through them.

How does the change in curvature of the eye lens helps us in the process of seeing the nearby objects clearly?

State the range of the power of accommodation of a normal human eye.

Draw a ray diagram to show the correction of eye defect of an old man who can not see an object placed closer than 1 m from his eye, clearly.

Why does an electric bulb become dim when an electric heater in parallel circuit is switched ON?

How to connect three resistors each of resistance 8 Ω, so that the equivalent resistance of the combination is 12 Ω? Draw diagram of the combination and justify your answer.

An object is placed at a distance of 30 cm in front of a convex lens of focal length 15 cm. Use lens formula to determine the position of the image. What will be the size of the image in this case?

Draw the ray diagram for refraction of light through a glass prism and mark angle of refraction and angle of deviation.

When the path of a light ray refracted through a glass prism is reversed how will the angle of deviation change? Explain.

(a) If the ammeter reading is X ampere with nichrome wire of length ‘l’, then what will be the ammeter reading if the length of nichrome wire is doubled with same area of cross-section?

(b) What happens to the ammeter reading if the area of cross-section of nichrome wire is doubled, keeping the length of wire ‘l’ the same?

(c) Define ‘resistivity’. Write its SI unit. Compare the resistivity of an alloy with its constituents metals.

OR

(c) Give reason:

(i) Tungsten is used almost exclusively for making the filament of electric lamps.

(ii) Conductors of bread-toasters are made of an alloy rather than a pure metal.

List any two features of the electric current used in the houses of India.

Distinguish between Direct current and alternating current.

How will you identify live wire and neutral wire in a domestic electric circuit?

Why is fuse an important component in our electric circuits?

Distinguish between overloading and short-circuiting of circuit.

Giving reason explain what type of materials are used in fuse wires.