Class 10

Practicing Chemistry Class 10 Kerala Syllabus Question Paper Set 4 English Medium helps identify strengths and weaknesses in a subject.

Chemistry Class 10 Kerala Syllabus Model Question Paper Set 4

Time: 1½ Hours
Score: 40 Marks

Instruction:

1. First fifteen minutes are cool off time. Read the questions carefully during this time:
2. Write the answers according to the instructions.
3. Consider the score while writing the answers.
4. Answer only one question for questions having choice.

Answer all the questions from 1 to 4. Each question carries l score. (1 × 4 = 4)

Question 1.
The Industrial preparation of Ammonia is known as …
a) Haber process
b) Contact process
c) Ostwald process
d) Bosch process
Answer:
a) Haber process

Question 2.
Statement 1: M shell contains a maximum of 18 electrons.
Statement 2: M shell has nine orbitals.
Which of the following options is true, regarding these statements?
A. Statements 1 and 2 are correct.
B. Statement 1 is correct, but 2 is not correct.
C. Statement 1 is not correct, but 2 is correct.
D. Statements 1 and 2 are not correct.
Answer:
A. Statements 1 and 2 are correct.

Question 3.
Match the following

Nature of Ore	Concentration method
(a) Ores are less dense than the impurities	(i) Levigation
(b) A solvent which dissolves the ore is used	(ii) Froth Floatation

A. (a) – ii, (b) – i, (c) – iii
B. (a) – i, (b) – ii, (c) – iii
C. (a) – iii, (b) – i, (c) – ii
D. (a) – ii, (b) – iii, (c) – i
Answer:
D. (a) – ii, (b) – iii, (c) – i

Question 4.
An alkane X with four carbon atoms undergo thermal cracking to get the products Y and Z (symbols are not real). Choose the correct option
A. X – C₄H₈, Y – CH₄, Z – CH₂ – CH₂
B. X – C₄H₁₀, Y – CH₄, Z – CH₂ = CH₂
C. X – C₄H₆, Y – CH₂ = CH₂ Z – CH₂ = CH₂
D. X – C₄H₁₀, Y – CH₃ – CH₃, Z – CH₂ = CH₂
Answer:
D. X – C₄H₁₀, Y – CH₃ – CH₃, Z – CH₂ = CH₂

Two questions from 5 to 11 have a choice. Each question carries 2 scores. (7 × 2 = 14)

Question 5.
a) In which test tube displacement reaction take place

b) Why doesn’t the displacement reaction take place in one of the test tubes?
Answer:
a) Test tube 1
b) In the second test tube, Ag is less reactive than copper. So, a displacement reaction cannot occur.

Question 6.
The flow chart of the industrial preparation of sulphuric acid is given. Complete it.

Answer:
a) SO_{2 (Sulphur Dioxide)
b) H2S2O7(Oleum)}

Question 7.
(A) Analyse the following.

a) Write the structural formula of X.
b) What is its IUPAC name?
Answer:
a) CH₃ – CH₂ – CH₂ – CH₂-OH
b) Butanol

OR
(B) One molecule of an aliphatic organic compound has 5 carbon atoms. It is identified as a saturated carboxylic acid.
a) Write the structural formula of this compound
b) Write the IUPAC name of a compound in this family with 4 carbon atoms.
Answer:
a) CH₃CH₂CH₂2CH₂COOH
b) Butanoic acid (CH₃CH₂CH_2COOH)

Question 8.
Choose the suitable method used in each of the following processes from the bracket.
[Liquation, Leaching, Froth floatation, Distillation]
a. Concentration of sulphide ores.
b. Refining of metals with low boiling points.
Answer:
a) Froth floatation
b) Distillation

Question 9.
Select from the box the correct gas law related to the given situations.
[Charles’s law, Boyle’s law, Avogadro’s law]
a) An inflated balloon kept in the sunlight bursts after some time.
b) The size of an air bubble rising from the bottom of an aquarium increases.
Answer:
a) Charles’s law
b) Boyle’s Law

Question 10.
The atomic number of an element is 11.
a) Write the sub-shell electronic configuration of this element.
b) What is the common oxidation state shown by this element?
Answer:
a) 1s₂2s₂2p₆3s₁
b) +l

Question 11.
(A) a) Name the polymer used to make switches.
b) Write the IUPAC name of this polymer 1 l.
Answer:
a) (Bakelite)
b) Phenol formaldehyde resin

B. Polyc’ lene tercphthalate (Polyester) is a very useful pnL tier.
a) What are the monomers of Polyethylene terephthalate (Polyester)?
b) Write any one use of this polyester?
Answer:
a) Ethylene glycol and Terephthalic acid
b) Manufacture of tarpaulin, bottles, fabrics, etc.

Two questions from 12 to 17 have a choice. Each question carries 3 scores. (6 × 3 = 18)

Question 12.
Graph of a reversible process, Img- 1 heat is given. Analyse the graph and answer the following questions.

a) Identify the part of the graph that represents the forward reaction [OA, BA, AC]
b) Identify the part of the graph that represents the equilibrium state
c) From the given statements, select the correct ones regarding chemical equilibrium.
i. Chemical equilibrium is static at the molecular level.
ii. Both reactants and products co-exist.
iii. The rates of forward and backward reactions are equal.
iv. Chemical equilibrium is attained in an open system.
Answer:
a) BA
b) AC
c) (ii) Both reactants and products co-exist.
(iii) The rates of forward and backward reactions are equal.

Question 13.
The figure given below represents the metals like
Fe, Cu, and Mg kept in dilute HCl

a) Which among these test tubes didn’t show any reaction? Which metal was kept in that test tube?
b) Which metal is present in test tube 1? Write the equation for the chemical reaction.
c) Arrange the given metals in the increasing order of their reactivity towards acids.
Answer:
a) 3rd test tube, Cu

b) Mg. Because Mg reacts vigorously with HC1 therefore more H₂ gas is produced.
Mg + 2HC1 → MgCl₂ + H₂

c) Mg > Fe > Cu

Question 14.
a) Complete the table.

Sulphide ore of zinc	Zinc blende (ZnS)
Carbonate ore of zinc	_____(i)_____
Sulphide ore of zinc	Zinc blende (ZnS)

b) Name the processes used in the conversion of zinc ore to zinc oxide after the concentration of the ore?
Answer:
a) (i) Calamine (ZnCO₃)
b) Roasting.
Zinc sulphide can be easily converted into its oxides by this method.

Question 15.
A) Compound (1) CH₃-CH₂ – CHO and Compound (2) CH₃-CH₂-CH₂-CHO are members of a homologous series.
a) Write the name of the family to which these compounds belong.
b) Write the IUPAC name of these compounds.
c) Write the structural formula of the functional isomer of compound (2)
Answer:
a) Aldehyde

b) (1) Propanal
(2) Butanal

c) CH₃-CO-CH₂-CH₃

OR
B) Pentan-2-one and pentan-3-one are a pair of isomers.
a) Write the structural formulae of these compounds.
b) To which family of organic compounds do they belong?
c) Write the structural formula of the functional isomer of these compounds
Answer:
a) CH₃-CO-CH₂-CH₂CH₃
CH₃CH₂COCH₂CH₃
b) Ketone
c) CH₃CH₂CH₂CH₂CHO

Question 16.
From the given statements, select and write down those related to gases:
a) The energy of the molecules is very high.
b) The force of attraction between the molecules is very high.
c) The distance between the molecules is very high.
d) The freedom of movement of the molecules is very low.
e) Since the collisions of the molecules are elastic in nature, there is no loss of energy.
f) As the molecules are so far apart, the volume of gaseous molecules is negligible in comparison with the total volume of the gas.
Answer:
a) The energy of the molecules is very high.
c) The distance between the molecules is very high.
e) Since the collisions of the molecules are elastic in nature, there is no loss of energy.
f) As the molecules are so far apart, the volume of gaseous molecules is negligible in comparison with the total volume of the gas.

Question 17.
A. (i) CH₄ + 2O₂ → _____ + 2H₂O + Heat
(ii)
a) Complete the chemical equation (i).
b) Name the reaction (ii).
c) Write any one use of Teflon?
Answer:
a) CH₄ + 2O₂ → CO₂ + 2H₂O + Heat
b) Polymerisation
c) Used to coat the inner surface of nonstick cookware.

OR
B. a) How is methanol prepared industrially?
b) Write the chemical equation of the reaction for the formation of methanol.
c) Write two uses of methanol.
Answer:
a) Methanol is produced industrially by combining carbon monoxide with hydrogen in the presence of catalysts.

b)

c) Methanol is used as a solvent in the manufacture of paint, for making varnish, and for making formalin.

Question 18 has a choice. It carries 4 scores.

Question 18.
A. Two statements regarding a shell are given below
• The last electron of this atom fills into the shell with principal quantum number n = 3
• This shell contains a total of 2 electrons.
a) Write the subshell electron configuration of this atom.
b) What is the total number of orbitals in the shell with n = 2?
c) Write the names of subshells present in the shell
d) How many orientations will be there for a subshell with l = 1
Answer:
a) ls²2s²2p⁶3s²
b) Total orbitals = n² = 2² = 4
c) The principal quantum number n = 2 can have angular momentum quantum numbers 1 from 0 to n-1.
For n = 2:
l = 0 (s-subshell)
l = 1 (p-subshell)

d) The total number of orientations is 2l + 1.
For the subshell with l = 1 (the p-subshell) m_l values are -1, 0, +1
Total number of orientations = 2l + 1
= (2× 1) + 1 = 3

OR
B. The last electron of an atom is added to the 3d subshell. There are 7 electrons in this subshell. Answer the following questions regarding this atom.
a) What is its atomic number?
b) Write its complete electron configuration.
c) To which block does it belong?
d) Find its period number and group number?
Answer:
a) 27
b) ls²2s²2p⁶3s²3p⁶3d⁷4s²
c) d block
d) Period – 4 and Group – 9

Practicing Chemistry Class 10 Kerala Syllabus Question Paper Set 3 English Medium helps identify strengths and weaknesses in a subject.

Chemistry Class 10 Kerala Syllabus Model Question Paper Set 3

Time: 1 ½ Hours
Total Score: 40

Instruction:

1. First fifteen minutes are cool off time. Read the questions carefully during this time:
2. Write the answers according to the instructions.
3. Consider the score while writing the answers.
4. Answer only one question for questions having choice.

Answer all the questions from 1 to 4. Each question carries 1 score. (1 × 4 = 4)

Question 1.
Which substance is deposited at the cathode when aqueous Sodium Chloride is electrolysed?
[Oxygen, Chlorine, Sodium, Hydrogen]

Set 1	Set 2
(a) H2C2O4	(i) Acid salts
(b) NaOH	(ii) Tribasic acid
(c) H3PO4	(iii) Alkali
(d) NH4C1	(iv) Dibasic acid

Answer:
Hydrogen

Question 2.
Match the following.
Choose the correct answer from the options given below.
A. (a) – (iv), (b) – (iii), (c) – (ii), (d) – (i)
B. (a) – (i), (b) – (iii), (c) – (ii), (d) – (iv)
C. (a) – (iii), (b) – (iv), (c) – (ii), (d) – (i)
D. (a) – (ii), (b) – (iii), (c) – (iv), (d) – (i)
Answer:
A. (a) – (iv), (b) – (iii), (c) – (ii), (d) – (i)

Question 3.
Statement 1: Roasting refers to heating the concentrated ore at a temperature below the melting point in the presence of air.
Statement 2: Calcination refers to heating the concentrated ore in limited quantities or absence of air at a temperature below the melting point. Which of the following options is true, regarding these statements?
A. Statements 1 and 2 are correct.
B. Statement 1 is correct, but Statement 2 is not correct.
C. Statement 1 is not correct, but Statement 2 is correct.
D. Statements 1 and 2 are not correct.
Answer:
A. Statements 1 and 2 are correct.

Question 4.
To which category the compound CH₃ – COO – CH₃ belongs to?
a) Carboxylic acid
b) Ethene
c) alcohol
d) Ester
Answer:
d) Ester

Two questions from 5 to 11 have a choice. Each question carries 2 scores. (7 × 2 = 14)

Question 5.
Given Mass: 45 grams of water (H₂O), Molecular Mass of Water: 18 u
a) Calculate the number of moles of water molecules.
b) Calculate the number of molecules in the given mass.
Answer:
a) Number of Moles = \(\frac{45}{18}\) = 2.5moles
b) Number of Molecules = 2.5 × 6.022 × 1023
= 1.51 × 10²⁴ molecules

Question 6.
A. Which subshell is represented by each pair of the quantum number values given below?
a) n = 1, l = 0
b) n = 2, l = 1
Answer:
a) 1s
b) 2p

OR
B. Find the oxidation state of s-block elements in the following compounds.
a) Na₂O
b) KBr
Answer:
a) Sodium – +1
b) Potassium – +1

Question 7.
A student dissolves ammonium chloride (NH₄C₁) in water and finds the solution is acidic. Explain this observation by answering the following questions.
a) Identify the acid and base that react to form ammonium chloride (NH₄C₁).
b) Which is stronger, the acid or the base?
Answer:
a) The acid is Hydrochloric acid (HC1) and the base
is Ammonium hydroxide (NH₄OH).
b) The acid (hydrochloric acid) is stronger.

Question 8.
Complete the table.

Metal	Method of refining	Reason for selecting the method
Lead	(a)	Low melting point
Cadmium	Distillation	(b)

Answer:
a) Liquation
b) Low boiling point

Question 9.
A. The structure of two organic compounds is given below:
(i) CH₃ – CH₂ – CH₂ – CH₂ – OH
(ii) CH₃ – CH₂ – O – CH₂ – CH₃
a) Write the molecular formula of these compounds.
b) Write the structural formula of a position isomer of compound I
Answer:
a) C₂H₁₀
b) Butan – 2 – ol

OR
B. a) Write the structural formulae and IUPAC names of any two metamers of the compound
CH₃ – CH₂ – CH₂ – O – CH₂ – CH₂ – CH₃

b) Write the molecular formula of the given compound.
Answer:

b) C₆H₁₄O

Question 10.
A student draws the arrangement of a galvanic cell as shown below. Find out if there is any mistake? If so, draw the correct picture of the galvanic cell.

Answer:
Each metal should be placed in its own salt solution; that is, the Zn rod should be dipped in ZnS04, and the Cu rod should be dipped in CuS04.If the arrangement is correct, electron flow is from Zinc to copper.

Question 11.
a) Which among the following is a condensation polymer?
(Polyvinyl chloride, nylon 66, Teflon)
b) What are the monomers of nylon 66?
Answer:
a) Nylon 66
b) Adipic acid, Hexamethylenediamine.

Two questions from 12 to 17 have a choice. Each question carries 3 scores. (6 × 3 = 18)

Question 12.
The volume of 2 mol of hydrogen gas at 1 atm pressure and 273 K is 44.8 L.
a) Name the scientist who established the relationship between the volume and pressure of a gas through experiment.
b) What will be the new pressure if the volume of hydrogen gas is changed to 22.4 L?
c) Suggest a method to increase the volume of this gas without changing the pressure and mass.
Answer:
a) Robert Boyle
b) P₁V₁ = P₂V₂
P₁ = 1 atm
V₁ = 44.8L
V₂ = 22.4L
p₂ = p₁ V₁ /V₂
p₂ = \(frac{1 \times 44.8}{22.4}\) = 2 atm

c) Increase the temperature

Question 13.
A. The following are two facts related to the manufacture of an industrially important metal.
• The ore is treated with a hot NaOH solution.
• Electricity is used as the reducing agent to extract the metal.
(i) These facts are related to the production of which metal?
(ii) What is the reason for using electricity as the reducing agent?
(iii) Which substance is used as the electrolyte here?
Answer:
(i) Aluminium
(ii) Aluminium is a highly reactive and electropositive metal.
(iii) Molten cryolite (Na₃AlF₆)

OR
B. Corrosion is a process by which iron is converted into its oxide. This is an oxidation reaction.
(i) What is oxidation?
(ii) Complete the following chemical equation.
…. Fe + ….. Oz → …Fe₂O₃
(iii) Suggest two methods for preventing the corrosion of iron.
Answer:
(i) The process involving loss of electrons in a chemical reaction is called oxidation.

(ii) 4Fe + 3O₂ → 2Fe₂O₃

(iii)
• Painting or coating
• Galvanization

Question 14.
Analyse the equation and answer the following questions.

a) What is the name of this chemical reaction?
b) What is the name of the ester formed?
c) Write any two uses of esters.
Answer:
a) Esterification
b) Methyl ethanoate
c) Used to make artificial perfumes Used-to make juices.

Question 15.
Write the structural formula of the compounds given below.
a) Propan-l-ol
b) Propanal
c) Propanone
Answer:
a) CH₃CH₂CH₂OH
b) CH₃-CH₂-CHO
c) CH₃-CO-CH;

Question 16
(A)
a) Draw a diagram of the setup for electroplating gold onto a copper bangle and label its parts
b) What are the advantages of electroplating?
c) A picture of the arrangement of copper plating on an iron bangle is given below. What are the mistakes in this?

Answer:
a)

b) It enhances the beauty of metal Prevents corrosion

c) Copper should be connected to the positive terminal of the battery.
The iron bangle should be connected to the negative terminal of the battery.
Copper sulfate solution should be used as the electrolyte.

B. Analyse the pictur of an experiment.

a) What is the reason for the decrease in the green colour of the FeS04 solution?
b) The equation for this reaction is given below. Complete it.
Zn + FeSO₄  ____ + ZnSO₄
c) If Pb is used instead of Zn, no reaction takes place. From this, what inference regarding the reactivity of lead can be obtained?
Answer:
a) Zn displaces iron from the FeS0₄ solution.
b) Zn + FeS0₄ → Fe + ZnS0₄
c) Pb is less reactive than Zn.

Question 17.
Which of the following is’not correct in the subshell electron configuration?
a) 1s² 2s² 2p⁷
b) 1s² 2s² 2p²
c) 1s² 2s² 2p⁶3s¹
d) 1s²2s²⁶3s²3p⁶3d²4¹
e) 1s²2s²⁶3s²3p⁶3d²4²
Answer:
The incorrect subshell electron configuration is
a) ls²2s²2p⁷
c) ls²2s²2p⁵3s¹
d) ls²2s²2p⁶3s²3p⁶3d²4s¹

Question 18 has a choice. It carries 4. scores.

a) How many hydrogen molecules are required to convert CH = CH (ethyne) into C₂H₆ (ethane)?
b) Write the chemical equation of the reaction.
c) To which category does this chemical reaction belong?
d) Complete the chemical equation,
CH ≡ CH + HCl → A
Answer:
a) 2 Flydrogen molecules (4 Hydrogen atoms)
b) CH = CH + H₂ → CH₂ = CH₂ + H₂ → CH₃ – CH₃
Or (C₂H₆)
c) Addition reaction
d) CH = CH + HC1 → CH₂ = CHC1

OR
B. a) Identify A, B, C and D in the given chemical reactions.

b) What is wash?
c) How is rectified spirit obtained from the wash?
d) What is the purpose of denaturing rectified spirit?
Answer:
a) A – Invertase,
B – Fructose (C₆H₁₂O₆),
C – Zymase,
D – Carbon dioxide (2CO₂)

b) 8-10% ethanol obtained by the conversion of glucose and fructose by the action of the enzyme zymase is known as ‘wash’.

c) When wash is subjected to fractional distillation, 95.6% of ethanol is obtained. This is known as rectified spirit.

d) Ethanol is an organic compound used in the manufacture of various other organic compounds.

In such situations, toxic substances like methanol/ pyridine/rubber distillate, etc., are added to ethanol in order to prevent its misuse as a beverage. Ethanol thus obtained is called denatured spirit.

Practicing Chemistry Class 10 Kerala Syllabus Question Paper Set 2 English Medium helps identify strengths and weaknesses in a subject.

Chemistry Class 10 Kerala Syllabus Model Question Paper Set 2

Time: 1 ½ Hours
Total Score: 40

Instruction:

1. First fifteen minutes are cool off time. Read the questions carefully during this time:
2. Write the answers according to the instructions,
3. Consider the score while writing the answers.
4. Answer only one question for questions having choice.

I. Answer all the questions from 1 to 4. Each question carries 1 score.

Question 1.
Bauxite is the ore of. metal
a) Iron
b) Aluminium
c) Zinc
d) Copper
Answer:
b) Aluminium

Question 2.
Match the following.

Category	Example
(a) Analgesics	i) Paracetamol
(b) Antipyretics	ii) Dettol
(c) Antiseptics	iii) Aspirin

Choose the correct answer from the options given below.
A. (a)-iii, (b)-i, (c)-ii
B. (a)-ii, (b)-i, (c)-iii
C. (a)-i, (b)-ii, (c)-iii
D. (a)-i, (b)-iii, (c)- ii
Answer:
A. (a)-iii, (b)-i, (c)-ii

Question 3.
Which of the following metals reacts vigorously with diluted hydrochloric acid?
a) Gold
b) Magnesium
c) Lead
d) Iron
Answer:
b) Magnesium

Question 4.
Statement 1: Nitrogen, Phosphorous and potassium are the three elements that plants need in large quantities. They are called as primary nutrients.

Statement 2: Elements like Iron and manganese are needed by plants only in very small amounts. They are called micronutrients. Which of the following is correct regarding the above statements?
A. Both statements are correct
B. Both statements are not correct
C. Only statement 1 is correct
D. Only statement 2 is correct
Answer:
A. Both statements are correct

II. Two questions from 5 to 11 have a choice. Each question carries 2 scores. (7 × 2 = 14)

Question 5.
Analyse the structural formulae of the two pairs of compounds given below.
(i) CH₃ – CH₂ – CH = CH₂
(ii) CH₃ – CH = CH – CH₃
a) Write their IUPAC names.
b) What type of isomerism do they exhibit?
Answer:
a) (i) But-l-ene
(ii) But-2-ene

b) Their molecular formulae are the same, but the position of the double bond differs. Hence, they exhibit position isomerism

Question 6.
a) Which of the given polymers is used to coat the inner surface of cookware?
(Polythene, Polyvinyl chloride, Teflon)
b) What is the monomer of this polymer?
Answer:
a) Teflon
b) Tetrafluoroethene (CF₂ = CF₂)

Question 7.
A) Haematite is converted into iron by using the blast furnace.
a) Which substances are fed into the blast furnace along with the ore of iron?
b) Which compound acts as the reducing agent in the blast furnace?
Answer:
a) Limestone, Coke
b) Carbon monoxide (CO)

OR
B) Find the relation and write the answer.
(i) Zinc sulphide : Roasting
Calcium carbonate : ____(a)____

(ii) Magnetite : Magnetic separation
Bauxite : ____ (b) ____
Answer:
a) Calcination
b) Leaching

Question 8.
A few subshells are given. Find the values of n and l.
a) 2s
b) 4p
Answer:
a) n = 2 and l = 0
b) n = 4 and l = 1

Question 9.
448 L of gas is stored in a cylinder at 0°C and 1 atm pressure.
a) How many moles of molecules does this gas contain?
b) What is the number of molecules in this sample?
Answer:
Volume of the gas (V) = 448 L
Temperature (T) = 0 °C
(which is standard temperature)
Pressure (P) = 1 atm
(which is standard pressure)
Number of moles = \(\frac{\text { Volume at STP }}{22.4 \mathrm{~L}}\)
= \(\frac{448 \mathrm{~L}}{22.4 \mathrm{~L}}\)
= 20 moles
Therefore, the gas contains 20 moles of molecules.

b) Number of molecules
= 20 × 6.022 × 10₂₃ molecules.

Question 10.
A galvanic cell is made up of the following half-cells:
• A magnesium electrode immersed in magnesium sulphate solution.
• A nickel electrode immersed in nickel sulphate solution.
The reactions taking place in the half-cells are given.
Mg(s) → Mg²⁺ (aq) + 2e^–
Ni²⁺(aq) + 2e^– → Ni(s)
Draw the cell diagram and label the anode, cathode and direction of flow of electrons.
Answer:

Question 11.
a) Complete the equation of ionisation of phosphoric acid.

b) What will be the basicity of H₃PO₄?
Answer:
a) H₃PO₄ → 3H⁺ + PO₄³
b) Three (3)

OR
B) Certain fertilizers are given.
Urea, sodium nitrate, ammonium phosphate, potassium chloride
Complete the table.

Functions in plants	Fertilisers that can be used
To accelerate plant growth	___(a)___
To increase productivity	Ammonium Phosphate
To boost the immunity of plants	___(b)___

Answer:
a) Urea, Sodium nitrate
b) Potassium chloride

II. Two questions from 12 to 17 have a choice. Each question carries 3 scores. (6 × 3 = 18)

Question 12.
The structural formulae of two familiar compounds are provided below. Analyse them,
i) CH₃ – CH₂ – CH₂ – OH
ii)

a) What is the functional group present in them?
b) Write their IUPAC name.
Compound ___(i)___
Compound ___(ii)___
c) What type of isomerism do they exhibit?
Answer:
a) Hydroxyl (- OH)

b)
(i) Propan-1-ol
(ii) Propan-2-ol

c) Position isomerism.

Question 13.
A) As shown in the galvanic cell of the given figure, place a silver electrode in a solution of silver nitrate and a lead electrode in a solution of lead nitrate. Connect the two electrodes using a copper wire. Also, connect the two beakers using a salt bridge.

a) Where do oxidation and reduction occur?
b) In which direction do electrons flow through the copper wire?
c) Will the cell voltage vary if the two solutions are diluted alternately?
Answer:
a) Anode is where oxidation occurs. The lead (Pb) electrode acts as the anode. The cathode is where reductions occur. The silver (Ag) electrode acts as a cathode.

b) From the lead electrode to the silver electrode

c) Yes, the cell voltage will vary if the solutions are diluted. The cell voltage depends on the concentration of the ions. Diluting the solutions changes the ion concentrations, which affects the electrode potential and thus alters the overall cell voltage.

OR
B) a) Which is the anode and cathode in the Mg – Ag galvanic cell?
b) Write the reaction taking place at the anode and cathode of this cell.
c) Write the equation of a redox reaction.
Answer:
a) Anode – Mg, Cathode – Ag
b) Anodic reaction: Mg → Mg²⁺ + 2e^–
Cathodic reaction: 2Ag + 2e → 2Ag
c) Redox reaction: Mg + 2Ag⁺ → Mg⁺ + 2Ag

Question 14.
Choose the correct answer from the box.
Ethanoic acid, Sodium hydroxide, Methanol, Glycerol, 95.6% Ethanol
a) Which alcohol is known as the wood spirit?
b) Which substance is known as rectified spirit?
c) Name the acid present in vinegar?
Answer:
a) Methanol
b) 95.6% ethanol
c) Ethanoic acid

Question 15.
The element Cu, with atomic number 29, undergoes a chemical reaction to form an ion with an oxidation state of +2.
a) Write the subshell electron configuration of this ion.
b) Is it possible for this element to exhibit a different oxidation state? Why?
c) Write the chemical formula of a compound formed when this element reacts with chlorine.
Answer:
a) ls² 2s²2p⁶3s²3p⁶4s²3d⁹

b) Yes. Being a d-block element, there is only a very small difference in the energy levels of electrons in 4s and 3d. This allows for the loss of electrons from the 4s and 3d orbitals, resulting in variable oxidation states.

c) CuCl₂

Question 16.
A) Zinc is an industrially important metal
a) Which is the ore of Zinc?
b) Write the name of the concentration method used for Zinc ore?
c) What is the process used in the conversion of zinc ore to zinc oxide after the concentration of the ore?
Answer:
a) Zinc blende (ZnS)
b) Froth floatation
c) Roasting

OR
B) Alloys containing iron are given. Find a, b, c

Alloys	Constituent elements	Uses
Alnico	___(a)___	For the manufacture of permanent magnets
___(b)___	Fe, Cr, Ni, C	Resist the corrosion of iron. Making of utensils.
Silicon steel	___(c)___	Used in the core of electromagnetic instruments like motors, generators, transformers etc.

Answer:
a) Fe, Al, Ni, Co
b) Stainless steel
c) Fe, Si, C

Question 17.
Find the samples with equal volumes from the ones given below at STP.
a) 64g O₂
b) 44g CO₂
c) 2 × 6.022 × 10²³ NH₃ molecules SO₄
Answer:–
a) 64g O₂
No of moles = \(\frac{\text { Mass }}{\text { Molar mass }}=\frac{64}{32}\) = 2 mole
Volume of Oxygen = No of moles × 22.4L = 2 × 22.4L = 44.8L

b) 44g CO₂
No of moles = \(\frac{\text { Mass }}{\text { Molar mass }}=\frac{44}{44}\) = 1 mole
Volume of 1 mole CO₂ = No of moles × 22.4L = 1 × 22.4L = 22.4L

c) 2 × 6.022 × 10²³ NH3 molecules No of moles = 2
Volume at STP = No of moles × 22.4L = 2 × 22.4L = 44.8L Therefore,
(a) and (c) have equal volume.

Question 18 has a choice. It carries 4 scores. (1 × 4 = 4)

Question 18.
A) A reversible reaction at equilibrium is given.

a) Write the equation of the forward reaction.
b) How do the following changes affect the rate of forward reaction?
i. Adding more oxygen.
ii. Increasing pressure
c) What is the effect of a catalyst in a reversible reaction at equilibrium?
d) How does an increase in the concentration of NO (Nitric oxide) influence the rate of the forward reaction?
Answer:
a) 2NO(g) + O₂(g) → 2NO₂(g)
b)
i. Increases
ii. Increases
c) Catalyst does not affect reversible reactions at equilibrium.
d) Amount of product decreases.

OR
B)
a) The industrial preparation of sulphuric acid is known as _____.
b) Which is the catalyst used in this process?
c) Take some sugar in a watch glass and add a few drops of concentrated sulphuric acid into it. What is your observation? Which chemical property of sulphuric acid is shown here?
d) Why is concentrated sulphuric acid not used as a drying agent in the preparation of Ammonia?
Answer:
a) Contact process
b) Vanadium pentoxide (V₂O₅)
c) Sugar is converted into a black substance. The dehydrating nature of sulphuric acid is shown here.
d) Concentrated sulphuric acid is not used as a drying agent in the preparation of ammonia because ammonia is basic and can react with concentrated Sulphuric acid, and then it will form ammonium sulphate.

Practicing Chemistry Class 10 Kerala Syllabus Question Paper Set 1 English Medium helps identify strengths and weaknesses in a subject.

Chemistry Class 10 Kerala Syllabus Model Question Paper Set 1

Time: 1 ½ Hours
Total Score: 40

Instructions:

1. First fifteen minutes are cool off time. Read the questions carefully during this time:
2. Write the answers according to the instructions.
3. Consider the score while writing the answers.
4. Answer only one question for questions having choice.

I. Answer all the questions from 1 to 4. Each question carries 1 score. (4 × 1 = 4)

Question 1.
The metal which is refined by distillation is _____.
(Sn, Cu, Hg, Pb)
Answer:
Hg

Question 2.
Match the following

Choose the correct answer from the options given below.

(a) (b) (c)
A. (ii) (i) (iii)
B. (i) (ii) (iii)
C. (iii) (i) (ii)
D. (ii) (iii) (i)
Answer:
D. (ii) (iii) (i)

Question 3.
Which one of the following organic compounds undergoes an addition reaction?
A. CH₃ – CH₃
B. CH₄
C. CH₃C1
D. CH₂ = CH₂
Answer:
D. CH₂ = CH₂

Question 4.
Statement 1: Substitution reactions are chemical reactions in which an atom or group of atoms is replaced with another atom or group of atoms in a compound.

Statement 2: Polymerisation is the process by which simple molecules join together to form large complex molecules.
Which of the following options is true, regarding these statements?

A. Statements 1 and 2 are correct.
B. Statement 1 is correct, but 2 is not correct.
C. Statement 1 is not correct, but 2 is correct.
D. Statements 1 and 2 are not correct.
Answer:
A. Statements 1 and 2 are correct

II. Two questions from 5 to 11 have choice. Each question carries 2 scores. (7 × 2 = 14)

Question 5.
The structural formulae of four organic compounds are given.
(i) CH₃ – CH₂ -CH₂-CH₃
(ii) CH₃ – CH₂ – O – CH₃
(iii) CH₃ – CH₂ – CO – CH₃
(iv) CH₃ – CH₂ – CH₂ – OH
(a) Write the structural formula of the chain isomer of compound (i)
(b) Identify the pair of functional isomers.
Answer:
(a)

(b) (ii) and (iv)

Question 6.
Calcination and Roasting are two methods of conversion of concentrated ore into its oxide.
(a) How does Roasting differ from Calcination?
(b) Cu₂S ore is converted into Cu₂O by. ______ process.
Answer:
a) Roasting is the process of heating the metal ore at a temperature below its melting point in the presence of air
b) Roasting

Question 7.
(A) The IUPAC name of a hydrocarbon is 2, 3-Dimethylbutane.
(a) Write the structural formula of the given hydrocarbon.
(b) A hydrocarbon has 4 carbon atoms in the main chain. There are two methyl groups on the second carbon atom. Write its IUPAC name.
Answer:

(b) (b) 2,2-Dimethylbutane

OR
(B) Write the structural formula of given compounds
(i) 2,3-Dimethylbutane
(ii) But-2-ene
Answer:
(i) 2, 3-Dimethylbutane

(ii) CH₃ – CH = CH – CH₃

Question 8.
How do the following conditions affect a reversible reaction?
i) More reactants are added.
ii) Products are removed.
Answer:
i) The rate of forward reaction increases
ii) Rate of forward reaction increases

Question 9.
Copper is electroplated on an iron ring.
(a) Which electrolyte is used here?
(b) Which metal is connected to the positive terminal of the battery?
Answer:
a) Copper sulphate solution
b) Cu

Question 10.
(A) Ethanol is an alcohol that is extensively used for industrial purposes.
(a) What is rectified spirit?
(b) How does rectified spirit differ from absolute alcohol?
Answer:
a) Rectified spirit is 95.6% pure ethanol. It is obtained by the fractional distillation of wash.
b) Absolute alcohol is 99.5% pure ethanol. It is obtained by the fractional distillation of rectified spirit.

OR
(B) Consider the following chemical equation.

(a) Write the structural formula of A.
(b) What is the product obtained when A is subjected to polymerisation?
Answer:
a) CH₂ = CH₂
b) Polyethene

Question 11.
Choose the suitable method used in each of the following processes from the bracket.
[Liquation, Leaching, Troth floatation, Distillation]
(a) Concentration of sulphide ores.
(b) Refining of metals with low boiling points.
Answer:
a) Froth floatation
b) Distillation

III. Two questions from 12 to 17 have choice. Each question carries 3 scores. (6 × 3 = 18)

Question 12.
Chemical equations of the reactions taking place in the blast furnace during the industrial production of iron are given below.
(i) C + O₂ → CO₂ + Heat
(ii) CO₂ + C + Heat → 2CO
(iii) Fe₂O₃ + 3CO → 2Fe + 3CO₂
(iv) CaCO₃ → CaO + CO₂
(v) CaO + SiO₂ → CaSiO₃
Answer the following questions.
a) Which compound acts as the reducing agent?
b) What is the function of CaO in the production of iron?
c) Which is the slag formed here?
Answer:
a) Carbon monoxide (CO)
b) Act as a flux to remove Silica (SiO₂)
c) Calcium silicate (CaSiO₃ )

Question 13.
(A) The molecular mass of methane (CH₄) is 16.
(a) What is the mass of 1 GMM of CH₄?
(b) Calculate the number of moles in 160 g of CH₄
(c) What is the mass of 5 × 6.022 × 10²³ CH₄ molecules?
Answer:
a) 16g

b) Number of moles
= \(\frac{\text { Mass given in grams }}{\text { Gram molecular mass of the compound }}\)
= \(\frac{160 \mathrm{~g}}{16 \mathrm{~g}}\) = 10 moles

c) Number of moles x molecular mass
= 5 × 16 = 80 g

OR
(B) The CO₂ gas kept at STP has a volume of 112 L. [Hint: Molecular mass – 44]
(a) Find the number of moles of CO₂
(b) Calculate the mass of 112 L CO₂
(c) How many molecules of CO₂ are present in it?
Answer:
a) No. of molecules = Volume at STP/22.4
\(\frac{112}{22.4}\) = 5 moles

b) Mass = No. of moles x Molar mass
= 5 moles × 44 = 220g

c) No.of molecues = No.of moles × 6.022 × l0²³
= 5 × 6.022 × 10²³

Question 14.
A gas kept in cylinder A, having a volume of 5 L at 4 atm pressure, is completely transferred to cylinder B of volume 10 L at constant temperature.
(a) What is the volume of the gas in cylinder B?
(b) What will be the pressure in cylinder B?
(c) Which Gas law is associated with this situation?
Answer:
a) 10L
b) P₁V₁ = P₂V₂
P₁ = 4 atm
V₁ = 5L,
V₂ = 10 L
P₂ = ?
P₂ = P₁V₂/V₂
\(\frac{4 \times 5}{10}\) = 2 atm

c) Boyle’s law

Question 15.
Match columns A, B and C suitably.

A Characteristics of ore	B Method of concentration	C Example
Ore particles are heavier than the impurities	Froth floation	Tin stone
Ore particles are lighter than the impurities	Magnetic separation	Ore of gold
Magnetic nature of ore	Levigation	Zinc sulphide

Answer:

A Characteristics of ore	B Method of concentration	C Example
Ore particles are heavier than the impurities	Levigation	Ore of gold
Ore particles are lighter than the impurities	Froth floation	Zinc sulphide
Magnetic nature of ore	Magnetic separation	Tin stone

Question 16.
(A)
(a) The size of air bubbles rising from the bottom of a water tank increases. Give a reason.
(b) State the gas law related to it.
(c) The volume of a fixed mass of a gas at 2 atm pressure is 20 L. What will be its volume if the pressure increases four times without changing the temperature?
Answer:
a) Boyle’s Law
b) At a constant temperature, volume of a definite mass of gas is inversely proportional to its pressure.
c) 5L

OR
(B)
(a) If the volume of a gas at 127°C and 1 atm pressure is 1600 L, what will be the volume of the gas at 600 K and 2 atm pressure?
Answer:
\(\frac{P_1 V_1}{T_1}=\frac{P_2 V_2}{T_2}\)
P₁ = 1 atm
V₁ = 1600L
T₁= 127°C = 127 + 273 = 400 K
P₂ = 2 atm
T₂ = 600 K
V₂ = ?
\(\frac{1 \times 1600}{400}=\frac{2 \times V_2}{600}\)
V₂ = \(\frac{960000}{800}\) = 1200 L

(b) The volume of a certain mass of gas at 1 atm is 1600 L. What will be the volume if the pressure is increased to 4 atm (temperature remains unchanged)?
Answer:
P₁ V₁ = P₂ V₂
P₁ = 1 atm
V₁ =1600L
P₂ = 4 atm
V₂ = ?
1 x l600 = 4 x V₂
V₂ = \(\frac{1600}{4}\) = 400L

Question 17.

How do the following changes influence the amount of the product?
(a) Temperature decreases.
(b) Pressure increases.
(c) Ammonia produced is removed continuously from the system
Answer:
a) Amount of product increases
b) Amount of product increases
c) Amount of product increases

Question 18 has choice. It carries 4 scores. (1 × 4 = 4)

Question 18.
(A) The subshell electron configuration of chromium (₂₄Cr) is written in two ways.
(i) ls² 2s² 2p⁶ 3s² 3p⁶ 3d⁴ 4s²
(ii) ls² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹
(a) Which is the most stable configuration?
(b) Explain the reason for your answer
(c) Write the stable subshell electron configuration of coppeT (₂₉Cu)
(d) Write the period number and group number of copper.
Answer:
a) (ii) ls² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹
b) Half-filled d subshell has greater stability.
c) ls² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s¹
d) Period number = 4, Group number = 11

OR
(B) The subshell electron configuration of certain elements are given below:
A – ls² 2s² 2p⁶ 3s²
B – ls² 2s² 2p⁴
C – ls² 2s² 2p⁶ 3s² 3p⁶
D – Is² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²

i) Write the atomic number of the element ‘A’.
ii) Which is the inert gas among them?
iii) The element ‘D’ can form coloured compounds. Explain the reason.
iv) Write the chemical formulae of the compound formed by the elements ‘A’ and ‘B’
Answer:
i) 12
ii) C
iii) D – Transition elements
iv) ABb

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Board	Kerala Board
Textbook	SCERT, Kerala
Class	SSLC Class 10
Subject	SSLC Biology
Chapter	Previous Year Question Papers, Model Papers, Sample Papers
Year of Examination	2026, 2025, 2024, 2023, 2022
Category	Kerala Syllabus Question Papers

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Reviewing solved Biology Class 10 Kerala Syllabus Question Paper Set 4 English Medium helps in understanding answer patterns.

Biology Class 10 Kerala Syllabus Model Question Paper Set 4

Time: 1 ½ Hours
Total Score: 40

Instructions:

1. The first 15 minutes is cool-off time.
2. This time can be used for reading the questions and planning the answers
3. Write answers only according to the instructions and questions
4. While writing the answers, consider the score and time.

Questions from 1 to 4 carry 1 score each. (4 × 1 = 4 scores)

Question 1.
Communicable diseases are diseases caused by mi-croorganisms and transmitted from one person to another.

Which of the following are included in the category of communicable diseases?
1. Dengue fever
2. Chikungunya
3. Typhoid
4. Malaria
5. Diabetes

A. 1,2, and 3 only
B. 1,2, 3, 4, and 5.
C. 1,2, 3, and 4 only
D. 2, 4 only
Answer:
C. 1,2, 3, and 4 only

Question 2.
Find the correctly matched pair from the given answers.

Hypothalamus	Relay station of messages
Thalamus	Centre of memory
Pons	Regulates the rate of ventilation.
Cerebrum	Helps in maintaining homeostasis

(a) A: i, B: ii, C: iii, D: iv
(b) A: iii, B: i, C: iv, D: ii
(c) A: iii, B: iv, C: ii, D: i
(d) A: iv, B: i, C: iii, D: ii
Answer:
(d) A: iv, B: i, C: iii, D: ii

Question 3.
Select and write the correct answer.
Statement 1: Somatic chromosomes are chromo-somes that control physical characteristics.
Statement 2: The SRY gene on the X chromosome is responsible for the development of testis in the embryo.
Statement 3: The Y chromosome is comparatively smaller than that of the X chromosome.
(A) Statements 1, 2 are correct
(B) Statements 1, 3 are correct
(C) Statements 1,2,3 are correct
(D) Statements 2, 3 are correct
Answer:
(B) Statements 1, 3 are correct

Question 4.
Examine the statement and reason and select the correct answer.
Statement: Blood group A has both A and B anti-gens on the surface of red blood cells.
Reason: Blood group A contains only A antigen and anti-B antibodies.
(A) Both the statement and the reason are correct. The reason is the correct explanation of the state¬ment.
(B) Both the statement and the reason are correct. The reason is the wrong explanation of the state¬ment.
(C) Statement is correct. Reason is wrong.
(D) Statement is wrong. Reason is correct.
Answer:
(D) Statement is wrong. Reason is correct.

Questions from 5 to 11 carry 2 scores each. (7 × 2 = 14 scores)

Question 5.
Observe the picture and answer the questions given below.

(a) Identify the genetic processes responsible for variations.
(b) Identify the part indicated as (i), What is its peculiarity?
Answer:
a) Crossing over
b)Chiasma . The chromatids break at this region and the broken segments are exchanged with each other.

Question 6.
A. Prepare a flowchart on how smell is effected.
Answer:
While breathing, the particles responsible for smell enter the nasal cavity. → The particles gets dis-solved in the mucus produced by mucus membrane → Olfactory neurons in the mucus membrane get stimulated by special olfactory particles. → Re-ceptors generate impulses, and they travel through the olfactory nerve to reach the part of the brain recognising smell → The sense of smell is effected.

OR
B. We are unable to recognize smell and taste of food when we have cold. Can you say the reason?
Answer:
Smell influences tasting. During cold, excess mucus will be produced in the nasal cavity. This will obstruct the normal stimulation of olfactory receptors and hence, we are unable to recognize smell and feel the food tasteless.

Question 7.
The symptoms of a disease is given below.
Sudden onset of fever, headache, muscle pain, red-ness of the eye, vomiting
(a) Identity the disease.
(b) How this disease is transmitted?
Answer:
(a) Rat fever (Leptospirosis)
(b) Through wounds or through the mucous mem-branes of the eyes and nose from the water con-taminated with rat urine.

Question 8.
Complete the table related to Biology and Artificial Intelligence.

Personalised medicine	_____(a)_____
_____(b)_____	Analyses large amounts of genetic data and suggests simplification strategies

Answer:
(a) Analyses each individual’s genetic makeup and health information and recommends the most suit-able treatment regimens for them,

(b) Bioinformatics

Question 9.
Observe the illustration and answer the questions given below.

a) Identify the illustration.
b) Complete the illustration.
Answer:
(a) Position of DNA
(b) A – Chromosome B- DNA

Question 10.
A. Appu was taken by fear, on seeing a snake on his way back to school and then ran back.
a) Which part of the autonomous nervous system controls the body activities of Appu in the above situation?
b) What are the changes that takes place in the intestine and eye during the above situation?
Answer:
A.
a) Sympathetic nervous system
b) Peristalsis slows down in the intestine and the pupil in the eye dilates
OR

B. All reflex actions take place under the control of the spinal cord. Evaluate the statement and justify with suitable examples.
Answer:
All reflex actions are not under the control of the spinal cord. Some reflex actions are under the control of the cerebrum. These reflexes are known as cerebral reflexes. E.g., We blink our eyes when light suddenly falls on our eyes.

Question 11.
How these technologies helps in environmental con-servation.
a) Global Biodiversity Data Sensors
b) Bioremediation:
Answer:
a) A technology that collects information about biodiversity using satellite remote sensing, acoustic analysis and camera traps
b) Uses microorganisms and plants to remove pol-lutants from contaminated environments such as soil, water and air. This converts the pollutants into harmless compounds.

Questions from 12 to 17 carry 3 scores each. (6 × 3 = 18 scores)

Question 12.
What are the uses of DNA Fingerprinting
Answer:
To identify culprits, To identify genetic disorders and leam about hereditary diseases, To determine the biological relationship between parents and offsprin, To understand lineage by identifying fossils, To iden-tify victims of accidents or disasters, To track en-dangered species.

Question 13.
A. A plant produces hundreds of seeds. However, only a few among them attain complete maturity. What would be the circumstances that might lead a new plant species to evolve from this plant after millions of years?
Answer:
Overproduction : The plant produces more seeds than the environment can support. Most of them fail to grow due to limited resources.

Variations : Among the seeds that sprout, there are differences in traits like size, immunity, and seed production. Some variations are favourable, while others are not.

Struggle for Existence : Because of limited food, space, and other resources, the seedlings compete with each other for survival.

• Survival of the Fittest – Only those plants with favourable variations, like better adaptability, survive and grow to maturity. They are able to reproduce more effectively.
• Natural Selection – Favourable traits get passed on to the next generation. Over a long period of time, more variations accumulate, and new plants with different traits may emerge. Eventually, this leads to the evolution of a new species.

OR

B. Explain Lamarckism.
Answer:
Giraffes used to have short necks that ate food from the ground. Due to the scarcity of food, giraffes’ necks lengthened as a result of stretching their necks to reach leaves from higher branches. Acquired traits are passed down through generations, resulting in giraffes with longer necks.

Question 14.
A. Processes related to maintaining the equilibrium of the body are given below. Analyse and arrange them in the correct order.
a) Impulses are formed.
b) Muscular movements are coordinated.
c) Maintains the equilibrium of the body.
d) Sensory hair cells of the vestibular apparatus are stimulated.
e) Impulses reach the cerebellum.
f) Body movements create the movement of fluid inside the vestibule and semicircular canal.
Answer:
f) Body movements create the movement of fluid inside the vestibule and semicircular canal.
d) Sensory hair cells of the vestibular apparatus are stimulated.
a) Impulses are formed.
e) Impulses reach the cerebellum.
b) Muscular movements are coordinated.
c) Maintains the equilibrium of the body.

OR
B. Vision is enabled when the impulse from the retina reaches the cerebrum through the optic nerve.
a) Draw a flow chart showing the pathway of light from cornea to retina.
b) There is no vision at the point where the optic nerve starts. Why?
Answer:
a) LighE → Cornea → Aqueous humor → Pupil → Lens → Vitreous humor → Retina

b) Rod cells and cone cells arc absent in the pan from where the optic nerve stans (photo receptors are absent). So there is no vision.

Question 15.
Fill in the blanks in the illustration given below.

Answer:
A) tt
B) t
C) Tt
D) dwarf

Question 16.
Observe the illustration and answer the questions.

a) Which process is indicated in the illustration?
b) Which white blood cells participate in this process?
c) Write the various steps in this process in order.
Answer:
a) Phagocytosis.
b) Monocyte, neutrophil.
c) Phagocytosis – different stages:

1. The phagocyte cell is attracted to the site of infection by chemicals released by the pathogen or by signals from damage to the body.
2. The phagocyte cell uses its cell membrane to engulf the pathogen. This cavity inside the cell where the pathogen has entered is called the phagosome.
3. The phagosome fuses with a lysosome. The resulting cavity is called the phagolysosome. This step is crucial for destroying the pathogen.
4. Inside the phagolysosome, powerful digestive
   enzymes (for example, hydrolytic enzymes) in the lysosome digest the pathogen’s cell wall and proteins.
5. After the pathogen is completely destroyed and digested, the unwanted debris is expelled from the cell.

Question 17.
What are vaccines? .Write the mechanism of the ac-tion of vaccines
Answer:
Vaccines are the substances used to get artificial immunity. Vaccines act as antigens in our body. It stimulates our immune system and helps to produce antibodies against the pathogens. These antibodies remain in the body and provide long-term protection against diseases. By taking the doses accurately vaccines help to gain protection from a disease for many years or even for a lifetime.

The 18th question carries 4 scores (1 × 4 = 4 scores)

Question 18.
A. Complete the table given below.

Hormones	Function
Testosterone	_____(a)_____
Estrogen	_____(b)_____
_____(c)_____	Lactation
_____(d)_____	Reabsorption of water from kidney

Answer:
(a) The activity of male sex organs, Sperm production, cycle. Control of secondary sexual characteristics Controls secondary sexual characteristics
(b) The activity of female sex organs. Production of ovum. Menstrual
(c) Oxytocin (d) ADH/ Vasopressin

B. The following figure shows the relationship of hypothalamus with an endocrine gland.

a) Write down the name of endocrine gland marked as X
b) Write down the name of hormones produced in A and B.
c) Mention the functions of hormones produced in B.
Answer:
a) Pituitary gland
b) A – Tropic hormone
B – Oxytocin and vasopressin
c) Oxytocin helps to contraction of smooth muscles and vasopressin helps in the reabsorption of water in the kidneys.

Reviewing solved Biology Class 10 Kerala Syllabus Question Paper Set 3 English Medium helps in understanding answer patterns.

Biology Class 10 Kerala Syllabus Model Question Paper Set 3

Time: 1 1/2 hours
Total Score: 40

Instructions:

1. The first 15 minutes is cool-off time.
2. This time can be used for reading the questions and planning the answers
3. Write answers only according to the instructions and questions
4. While writing the answers, consider the score and time.

Questions from 1 to 4 carry 1 score each. (4 × 1 = 4 scores)

Question 1.
Select the correct answer
Statement 1 : A dominant allele cannot fully hide the allele of the recessive trait in Co-dominance Statement 2 : Difference in skin colour is due to Multiple allelism.
(A) Statement 1 and statement 2 are correct
(B) Statement 1 and statement 2 are wrong
(C) Statement 1 wrong statement 2 correct
(D) Statement 1 correct statement 2 wrong
Answer:
(D) Statement 1 correct statement 2 wrong

Question 2.
Examine the statement and reason and select the correct answer.
Statement: The intensity of sound decreases ten¬fold for every 10 decibels.
Reason: For every 10 decibels, the intensity of sound increases tenfold.
(A) Both the statement and the reason are correct. The reason is the correct explanation of the statement.
(B) Both the statement and the reason are correct. The reason is the wrong explanation of the state¬ment.
(C) Statement is correct. Reason is wrong.
(D) Statement is wrong. Reason is correct.
Answer:
(D) Statement is wrong. Reason is correct.

Question 3.
Which of the following statements regarding junk genes is correct?
a) All genes in human DNA help in making proteins.
b) Genes that help in making proteins are called junk genes.
c) Junk genes have no function.
d) Junk genes are non-functional DNA segments.
Answer:
d) Junk genes are non-functional DNA segments.

Question 4.
Which of the following statements about rod cells are correct?
i) Rod cells are responsible for vision in dim light.
ii) Rod cells contain the visualpigment called rhodopsin.
iii) Rod cells help in detecting different colours.
iv) Rod cells are fewer than cone cells.
v) Rod cells are cone shaped.

(a) i, ii, iii correct
(b) i, ii correct
(c) ii, iii, v correct
(d) iii, iv, v correct
Answer:
(b) i, ii correct

Questions from 5 to 11 carry 2 scores each. (7 × 2 = 14 scores)

Question 5.
A. Redraw the given diagram and answer the fol-lowing questions:

(a) Identify a, b and c in the given diagram.
(b) What is the function of myelin sheath?
Answer:
(a) a – Synaptic knob, b – Axon, c – Dendron.

(b) The functions of myelin sheath are to increase the speed of transmission of messages, by acting as an insulator, to provide nourishment to the neuron and to protect the axon from external injuries.

OR
B. Ependymal cell, Oligodenrocyte, Microglial cell, Schwann cell, Astrocyte
(a) What are these cells called?
(b) What is the function of ependymal cells?
Answer:
(a) Neuroglial cells
(b) Ependymal cells play a role in the formation of cerebrospinal fluid.

Question 6.
Observe the picture and answer the questions given below.

(a) Identify the part indicated as X?
(b) How Action potential in neuron is formed?
Answer:
(a) Receptor potential in the recepters of the skin
(b) Electrical impulses are produced in receptors in response to external and internal stimuli. These 9. impulses are known as receptor potential. When such impulses are in higher concentration, action potential is formed in the neurons associated with receptors.

Question 7.
The illustration given below indicates the transmis-sion of impulses from one neuron to another. Observe the illustration and answer the following question.

(a) Identify the part in the illustration.
(b) Identify the chemical substance which is secreted from A. Give one example for this chemical substance.
Answer:
(a) Synapse
(b) Neurotransmitters. Acetylcholine/dopamine/ serotonin/endorphin

Question 8.
A. The hybridisation experiment conducted by Mendel considering the trait of the height is depicted in the illustration. Observe the illustration and answer the questions given below.

(a) Write the genotype of the first generation and the parental tall plant.
(b) If the first-generation plants are self-pollinated, what are the possible phenotypes of the plants obtained in the second generation, and in what ratio?
Answer:
(a) Parental tall plant-TT First geenration tall plant- Tt
(b) Tall and Dwarf in 3 : 1 generation

OR
B. Observe the illustration and answer the questions given below.

(a) Illustrate the cross between first generation and the parental tall plant.
Answer:

Question 9.
Balu: In the spinal cord and the cerebrum, white matter is seen outside, and grey matter is seen in¬side.
Ramu: In the cerebrum, the grey matter is seen outside, and the white matter is seen inside, But in the spinal cord, the white matter is seen outside, and the grey matter is seen inside.

In the group discussion related to the nervous system, Balu and Ramu said so.
(a) Whose opinion do you agree with?
(b) Explain white matter and grey matter.
Answer:
(a) Ramu’s opinion
(b) In the brain and the spinal cord, the part where myelinated heurons with are more abundant is called the white matter and the part where the cell bodies and parts of the neurons without a myelin sheath are seen is called the grey matter.

Question 10.
Complete the following illustration:

Answer:
A – Central canal,
B – Sensory impulses,
C – Ventral root

Question 11.
The details of blood groups of two persons are given in the table. Analyse them and answer the questions.

Person	Antigen	Antibody	Rh factor
X	B	a	Present
Y	A	b	Absent

a) Identify the blood groups of persons X and Y.
b) Can Y receive blood from X? Why?
Answer:
a) X-B Group, Y- A Group
b) No, the antigen in the donor’s blood will react with the antibody in the recipient’s blood and cause the blood to clot.

Questions from 12 to 17 carry 3 scores each. (6 × 3 = 18 scores)

Question 12.
Even using permanent mosquito repellents, mosquitoes cannot be completely destroyed. Write a scien-tific explanation for this statement based on the theory of evolution.
Answer:
Some mosquitoes develop resistance to insecticides. This is survival of the fittest. Those that are resistant to insecticides survive and the others die.

Question 13.
A. Given below is the portion of a poster.
Don’t take high eye pressure easy.
It may lead to blindness in future.

a) Which is the eye disease mentioned in the poster?
b) What is the reason for this condition?
c) What is the remedy for this disease?
Answer:
a) Glaucoma

b) • Blockage of reabsorption of aqueous humour
• Increase in the pressure inside the eyes

c) Laser surgery

OR
B. Redraw the diagram given below. Identify the parts and label it.

Answer:

a) Eustachian tube
b) Cochlea
c) Tympanum

Question 14.
What is the normal level of calcium in the blood? How is this level maintained?
Answer:
9-11 mg/100 ml blood. When the level of calcium in blood increases, thyroid gland secretes a hormone named calcitonin. It lowers the level of calcium in blood by depositing excess calcium in bones and by preventing the mixing of calcium with blood form the bones. When the level of calcium in blood decreases, parathyroid gland secretes parathormone. It increases blood calcium by reabsorbing it from the kidneys and also preventing the deposition of calcium in bones.

Question 15.
A. Observe the illustration of bacteria and answer the questions.

a) Which part is denoted as ‘X’?
b) What is the significance of ‘X’ in the process of genetic engineering?
Answer:
a) X: Plasmid/Circular DNA of bacteria

b) • Plasmids are used to transfer a gene from one cell to another as vectors
• Vectors that contain ligated genes enter target cells, and the new genes become a part of the genetic constitution of target cells

OR
B. Analyse the steps in the production of human insulin through genetic engineering and answer the questions.
Step 1. Cutting of insulin gene from human DNA
Step 2. Joining insulin gene with plasmid
Step 3. Plasmid with ligated insulin gene is inserted into bacterial cell
Step 4. Bacteria multiply in the culture medium
a) Which are the enzymes used in step 1 and 2.
b) What is the role of plasmid in this process?
c) Whether the succeeding generations of this bacterium have the ability to produce insulin. Why?
Answer:
a) Step 1: Restriction endonuclease (Genetic scissors) Step 2: Ligase (Genetic glue)
b) A gene from one cell is transferred to another cell
c) Yes. The human insulin gene becomes part of a part of the genetic constitution of target cells.

Question 16.
Observe the illustration and answer the questions given below.

(a) Identify the illustration.
(b) Identify the stages indicated as (i), (ii).
(c) Identify the parts indicated as A,B.
Answer:
a) Protein synthesis
b) (i) Transcription (ii) Translation
c) A – Amino acid B – Ribosome

Question 17.
Complete the table.

Plant Hormone	Function
Synthetic Auxins	__(A)__
__(B)__	Used to increase fruit size in grapevines and for stem elongation in sugarcane.
Synthetic Ethylene	__(C)__

Answer:
a) Used to induce root formation in stem cuttings. Also used as a weedicide (2,4-D)
b) Synthetic gibberellins
c) In agricultural sector, ethylene is used to make fruits ripen uniformly for harvest at the same time. Ethylene is used to ripen bananas and to-matoes simultaneously.

The 18,h question carries 4 scores (1 × 4 = 4 scores)

Question 18.
A. The symptoms of a disease is given below.
The main symptoms are a persistent cough for more than two weeks, fever, loss of appetite, weight loss, and fatigue. Sometimes blood may be seen in the sputum.
(a) Identify the disease.
(b) Name the pathogen.
(c) Waht are the part of the body affected by this disease?
(d) What is the Prevention, treatment of this disease?
Answer:
a) Tuberculosis
b) Mycobacterium tuberculosis
c) Although it mainly affects the lungs, it can also affect other parts of the body, such as the kid-neys, bones, and the brain
d) BCG vaccination. Long-term treatment by us¬ing multiple antibiotics (DOTS) simultaneously

OR
B. The name of a pathogen is given below. Human Immunodeficiency Virus
(a) Identify the disease caused by this pathogen.
(b) How the patogen affets our body?
(c) What is the mode of transmission of this disease?
Answer:
a) AIDS

b) Tlymphocytes. The virus attacks, and destroys them by multiplying using the genetic mecha-nism of Tlymphocytes. As a result, the body’s ability to fight diseases is reduced and gradu¬ally the condition reaches to AIDS.

c) HIV can be transmitted through sexual contact with an infected person, by sharing needles and syringes that are not HIV-free, through transfusion of blood or organs containing HIV, and from an infected mother to the foetus.

Reviewing solved Biology Class 10 Kerala Syllabus Question Paper Set 2 English Medium helps in understanding answer patterns.

Biology Class 10 Kerala Syllabus Model Question Paper Set 2

Time: 1 1/2 Hours
Total Score: 40

Instructions:

1. The first 15 minutes is cool-off time.
2. This time can be used for reading the questions and planning the answers
3. Write answers only according to the instructions and questions
4. While writing the answers, consider the score and time.

Questions from 1 to 4 carry 1 score each. (4 × 1 = 4 scores)

Question 1.
Which is the activity that takesplace in nucleus.
(a) tRNAs carry specific amino acids to the ribosome.
(b) mRNA is formed.
(c) Combine amino acids to make protein.
Answer:
(b) mRNA is formed.

Question 2.
Find the correctly matched pair from the given answers.

Short sight	Eye lens become opaque
Cataract	Prolonged deficiency of vitamin A
Night blindness	Enlarged eyeball
Hyperthyroidism	deficiency of vitamin A

(a) A: i, B: ii, C: iii, D: iv
(b) A: iii, B: i, C: iv, D: ii
(c) A: iii, B: iv, C: ii, D: i
(d) A: iv, B: i, C: iii, D: ii
Answer:
(b) A: iii, B: i, C: iv, D: ii

Question 3.
Examine the statement and reason and select the correct answer.
Statement: Insulin and Glucagon are the hormones that help in regulating the blood glucose level.
Reason: Insulin increases the blood glucose level, and Glucagon decreases the blood glucose level.
(A) Both statement and reason are correct. The reason is the correct explanation of the statement.
(B) Both statement and reason are correct. The reason is an incorrect explanation of the statement.
(C) Statement is correct. Reason is incorrect.
(D) Statement is incorrect. Reason is correct.
Answer:
(C) Statement is correct. Reason is incorrect.

Question 4.
What is CRISPR?
Answer:
CRISPR is a modem technology used to edit DNA with great precision

Questions from 5 to 11 carry 2 scores each. (7 × 2 = 14 scores)

Question 5.
A. Complete the table.

Non Mendelian Inheritance
Incomplete Dominance
_____ (b)

Cause
_____(a)
More than one gene controls the colour of the skin
Answer:
(a) A dominant allele cannot fully hide the allele of the recessive trait.
(b) Polygenic inheritance

OR
B. The hybridisation experiment conducted considering the trait of the height is depicted in the illustration. Ob-serve the illustration and answer the qustions given below.

(a) Write the dominant and recessive trait.
(b) What are the inferences made by Mendel from this hybridisation experiment?
Answer:
(a) dominant trait – Tall Recessive trait – Dwarf
(b) A trait is controlled by two factors.

When a pair of contrasting traits is subjected to hybridisation, only one of the contrasting traits is expressed in the offspring of the first generation and the other remains hidden. The trait that ap-pears in the first generation is called dominant trait and the hidden trait is called recessive trait. The trait hidden in the first generation reappears in the second generation.

Question 6.
Write reason.
Flowering in plants.
Answer:
Phytochrome, a light-sensitive pigment, plays a ma-jor role in photoperiodism. Phytochrome is synthe-sized in the fully developed leaves at the shoot apex. These leaves, perceive the length of day and night through phytochrome and transmit a signal to the shoot apical meristem to induce flowering. As a re-sult of this, genes that control flowering is stimu¬lated.

Question 7.
Didn’t you read the news report?
“Kollam: About 20 more bodies of those who died in the Paravoor Firing incident were identified through DNA testing and handed over to their relatives.”
a) What is the basis of a DNA test?
b) How is it possible to identify relations through the DNA test?
Answer:
(a) The arrangement of nucleotides in the DNA differs in different individuals
(b) The arrangement of nucleotides among close relatives have many similarities.

Question 8.
Observe the figure an answer the questions given below.

(a) Identify the white blood cell.
(b) What is the function of this white blood cell?
Answer:
(a) Neutrophil
(b) It engulfs and destroys bacteria, produces chemi-cals against pathogens.

Question 9.
Select the correct statements from the ones given below.
(A) Synthetic gibberellins are used to promote rooting in stem cuttings.
(B) Synthetic auxins are also used as weedicides.
(C) Synthetic ethylene is used for stem elongation in sugarcane.
(D) Synthetic auxins are used to promote rooting in stem cuttings.
(E) Synthetic gibberellins are used to increase fruit size in grapevines.
(F) Ethylene is used to ripen fruits like bananas and tomatoes simultaneously.
Answer:
(B) Synthetic auxins are also used as weedicides.
(D) Synthetic auxins are used to promote rooting in stem cuttings.
(E) Synthetic gibberellins are used to increase fmit size in grapevines.
(F) Ethylene is used to ripen fruits like bananas and tomatoes simultaneously

Question 10.
Some terms related to Recombinant DNA Technology is given below. Explain each with suitable example.
(a) Genetic glue
(b) Vector
Answer:
(a) Genetic glue – The enzyme that joins two DNA segments. Eg. Ligase
(b) Vector – It carries the genes to a host cell. Eg – Plasmids, which are the circular DNA in bacteria, and some viruses are used as gene vectors.

Question 11.
A. Observe the logo and answer the questions given below.

(a) Identify the logo
(b) What is the goal of this scientific initiative?
Answer:
(a) Human Genome Project (HGP)
(b) Completely understanding the information in the human genome.

OR
B. What are the findings of HGP?
Questions from 12 to 17 carry 3 scores each.
Answer:
The exact sequence of 300 crore base pairs in the human genome. Humans have 20,000 to 25,000 genes. Functional genes make up approximately 1-2% of human genome. The remaining bulk part is known as ‘junk DNA’.

Questions from 12 to 17 carry 3 scores each. (6 × 3 = 18 scores)

Question 12.
Observe the figure and answer the questions given below.

(a) Identify the disease.
(b) What is the cause of this disease.
(c) How the deformed red blood cells affects our body?
Answer:
(a) Sickle cell anaemia
(b) Defect of the gene that controls the production of haemoglobin
(c) Red blood cells become sickle-shaped. Their oxygen-carrying capacity decreases.
The deformed red blood cells get stuck in capil-laries and block blood flow.

Question 13.
Observe the illustration and answer the questions given below.

a) Identify the parts indicated as A, B, C, D.
b) How the part indicated as B is formed?
Answer:
(a) A- Histone protein B – Histone Octamer C-Nucleosome D – Centromere
(b) DNA and histone proteins are the primary components of a chromosome. Eight histone proteins join together to form a histone octamer. DNA strands wind around this octamer to form a structure called nucleosome.

Question 14.
A. Observe the figure given below and answer the question.

a) Identify A, B
b) Which is the pigment in A?
c) Which is the eye disorder related to B?
Answer:
(a)
A – Rod cells
B – Cone cells
(b) Rhodopsin
(c) Colour blindness

OR
B. “Allow anyone to take my eyes after my death”. These are the words of Raju, who was admitted to the hospital after a serious accident.
a) How will you react to this statement?
b) Is it difficult to donate eyes after death?
c) Is it possible to donate an organ while alive?
Answer:
(a) Raju is a noble and kind hearted person because Eye donation is a noble deed, as it brings happiness into the dark life of a blind person.

(b) No, Eyes can be removed within 6 hours and transplanted to the patient by surgery.

(c) Certain organs like, kidney, liver can be donated by a live donor.

Question 15.
Complete the flowchart filling the blanks:
Sound waves → A → Tympanum → B → C → D↓
Hearing ← F ← Auditory nerve ← Impulse ← E ↵
Answer:
A. Pinna
B. Ear ossicles
B. Oval window
D. Cochlea
E. Hair cells
F. Cerebrum

Question 16.
School science club is preapring a poster against the spreading of Amoebic encephalitis. What are the ideas that can be included in this poster ( Hint: pathogen, entry of pathogen in human body, prevention)
Answer:
Amoebic encephalitis is caused by an amoeba called Naegleria fowleri. It is mainly found in stagnant and warm fresh water. Infection occurs when contami-nated water enters the nose and the pathogens reach the brain through the nose. Therefore, the health department has informed that this disease can be prevented by avoiding bathing in or washing the face with stagnant and dirty waterbodies.

Question 17.
A. a) Complete the flowchart showing the blood clotting

b) Blood clotting is a defence mechanism to prevent the loss of blood through wounds. Mention the different stages of this process.
Answer:
a) A-Thrombin,
B – Fibrin
b) Stages of blood clotting:

a) When an injury occurs, the platelets and damaged tissues at the site produce an enzyme called thromboplastin. This converts a protein in the blood plasma called prothrombin into thrombin.
b) Thrombin then converts an inactive protein called fibrinogen into fibrin.
c) The fibrin forms a network of fibres that traps red blood cells, forming a blood clot.
d) This clot prevents further blood loss until the wound is healed.

OR
B. Identify the plant hormone that perform the following functions.
a) flowering and growth of leaves
b) ripening of fruits
c) dropping of leaves and fruits
d) growth of terminal bud.
Answer:
(a) Gibberelline
(b) Ethylene
(c) Abscisic acid/ ethylene in excess amount.
(d) Auxin

The 18th question carries 4 scores (1 × 4 = 4 scores)

Question 18.
A. Tabulate the following activities based on the tupe of nervous system that controls and given proper headings.
(a) Recognizes small of flower
(b) Taking decisions at the emeigency situations.
(c) Rate of heartbeat increases at times of crisis
(d) Production of hormone decreases after overcoming the crisis
Answer:
A. (a) Central nervious system
(b) Autonomous nervious system
(c) Sympathetic nervous system
(d) Parasympathetic nervious system B.

OR
B. Draw the diagram and label the following parts:

(a) The part that helps in the maintenance of homeostasis.
(b) That which acts as relay station of impulses to and from the cerebrum.
(c) The second largest part of the brain.
Answer:

(a) Hypothalamus
(b) Thalamus
(c) Cerebellum

Reviewing solved Biology Class 10 Kerala Syllabus Question Paper Set 1 English Medium helps in understanding answer patterns.

Biology Class 10 Kerala Syllabus Model Question Paper Set 1

Time: 1 1/2 Hours
Total Score: 40

Instructions:

1. The first 15 minutes is cool-off time.
2. This time can be used for reading the questions and planning the answers
3. Write answers only according to the instructions and questions
4. While writing the answers, consider the score and time.

Questions from 1 to 4 carry 1 score each. (4 × 1 = 4 scores)

Question 1.
Analyse the assertion and reason and choose the correct answer.
Assertion: Acquired traits are not inherited
Reason: Spontaneous mutations do not change the genetic makeup of organisms.
(a) The assertion and reason are correct, and the reason is the correct explanation of the assertion.
(b) Assertion and reason are correct but reason is not the correct explanation of assertion
(c) Assertion is correct, reason is wrong
(d) Assertion is wrong, reason is correct
Answer:
(c) Assertion is correct, reason is wrong

Question 2.
Complete the statement. ……. is the membrane that covers the anterior part of the eye, including the eyelids except the cornea.
Answer:
Conjunctiva

Question 3.
Find the correctly matched pair from the given answers.

(a) A Blood group	(i) No antigen
(b) B Blood group	(ii) No antibody
(c) AB Blood group	(iii) Antigen A
(d) O blood group	(iv) Antibody a

(a) A: i, B: ii, C: iii, D: iv
(b) A: iii, B: i, C: iv, D: ii
(c) A: iii, B: iv,C: ii, D: i
(d) A: iv, B: i, C: iii,D: ii
Answer:
(c) A: iii, B: iv,C: ii, D: i

Question 4.
Which are the statements realted to Cone cell?
(i) cylindrical in shape
(ii) contain the pigment called photopsin.
(iii) are about 45 lakhs
(iv) Recognise objects in both dim light and in shades of black and white.
(a) i, ii, iii
(b) ii, iii
(c) ii, iii, iv
(d) i, iv
Answer:
(b) ii, iii

Questions from 5 to 11 carry 2 scores each. (7 × 2 = 14 scores)

Question 5.
A. Observe the figure and answer the questions given below.

(a) Identify the fossil.
(b) What is the evolutionary significance of this fossil?
Answer:
(a) Archaeopteryx
(b) possesses the characteristic features of both reptiles and birds. Fossils which are connecting links reveal the evolutionary relationship between organisms.

OR
B. Write the answer of the following statements related to human evolutionary path.
(i) Contemporaries of modem man.
(ii) Were able to walk upright on two legs.
Answer:
(a) Homo neanderthalensis
(b) Homo erectus

Question 6.
A. Symptoms of a disease is given below. Circular reddish rashes, itching
(a) Identify the disease, pathogen.
(b) What is the mode of infestation of this disease?
Answer:
(a) Ring worm, Fungus
(b) Through the infected persons, contact, contaminated objects and from animals.

OR
B. Symptoms of a disease is given below.
White patches in the mouth, itching
(a) Identify the disease, pathogen.
(b) What is the mode of infestation of this disease?
Answer:
(a) Candidiasis, Fungus
(b) Direct contact, through sharing of clothes, through sexual contact

Question 7.
How does the perception of darkness occur through the action of photoreceptors and bipolar cells?
Answer:
Glutamate acts as the primary neurotransmitter in photoreceptors. Variations in glutamate production are responsible for the perception of darkness and light. In the dark, photoreceptors continuously produce glutamate. On bipolar cells (those that sense light) 14. are inactivated and off bipolar cells (those that sense . darkness) are activated. Off bipolar cells that indi¬cate the absence of light form impulses that reach the brain through the optic nerve, creating a sense of darkness.

Question 8.
Complete the table

Equipment	Use
___(a)	It is used to measure the oxygen level in a person’s blood and their pulse rate without using a needle.
Endoscope	___(b)

Answer:
(a) Pulse oximeter
(b) Is used to look inside the body to examine inter¬nal organs or cavities without surgery.

Question 9.
Name the gland which seen at the centre of brain, write its function.
Answer:
Pineal gland, melatonin the hormone produces by this gland helps to maintain the rhythm of our daily ac¬tivities.

Question 10.
Observe the table given below and make the appropriate pairs.

(a) DNA Profiling	(1) Treatment for genetic diseases
(b) Gene mapping	(2) Testing the arrangement of nucleotides
(c) Gene therapy	(3) The sum of genetic materials present in an organism
(d) Genome	(4) Locating the position of a gene in the DNA

Answer:

(a) DNA Profiling	(2) Testing the arrangement of nucleotides
(b) Gene mapping	(4) Locating the position of a gene in the DNA
(c) Gene therapy	(1) Treatment for genetic diseases
(d) Genome	(3) The sum of genetic materials present in an organism

Question 11.
Numerous biological techniques have been developed to help conserve the ecosystems and biodiversity. Justify the statement (Hint: Cryopreservation, Bioremediation)
Answer:
Cryopreservation: This is the process of preserving living cells, tissues and organs at very low tempera¬tures (-196°C). It is used for long-term preservation in fields such as medicine, agriculture and research. Bioremediation: Uses microorganisms and plants to remove pollutants from contaminated environments such as soil, water and air. This converts the pollut-ants into harmless compounds.

Questions from 12 to 17 carry 3 scores each. (6 × 3 = 18 scores)

Question 12.
Analyse the given statement and answer the questions. “The basis of blood grouping is the presence of antigen A and antigen B in red blood cells”. According to this, how many blood groups are there in humans? Write the antigen and antibody of each group.
Answer:
There are four main blood groups in humans, based on the presence (or absence) of the A and B antigens.

Blood group	Antigen	Antibody
A	A	b
B	B	a
AB	AB	–
O	–	a, b

Question 13.
A. “Suma murder case-trace of hair obtained from the size of incidence enabled to identify killer”.
a) Read the above news.Name the technology that helped to find thefiller?
b) Cite two other uses of this technology.
Answer:
(a) DNA finger printing

(b) • to solved parental dispute
• to identify culprits
• to identify persons

B. Observe the picture and answer the questions given below.

(a) Identify the parts indicated as A, B, C, D.
(b) What is the role of the part indicated as D in the above process
Answer:
(a) A – Tongue,
B – Papilla,
C – Taste bud,
D – Chemoreceptors

(b) Microvilli from each chemoreceptor. reach the minute pores present in the papilla. Saliva enters through this pore. Substances that give rise to taste are dissolved in saliva and stimulate chemoreceptors. The impulses produced by these molecules in the chemoreceptors reach the brain through the nerve and make the sense of taste.

Question 14.
Observe the logo and answer the questions given below.

a) Write down the climate B and C
b) Analyse the difference shown in B and C and write down its reasons.
c) Which hormone is responsible for the excreation of excess water through urine.
Answer:
(a) Human Microbiome Project (HMP)

(b) The number of microorganisms in our body is ten times more than the cells. They provide us many services,, including immunity, digestion, and the production and absorption Of vitamins. To develop knowledge about those, the Human Microbiome Project (HMP) was launched.

(c) HMP proved that the human body is not only composed of cells but also crores of microor-ganisms and their co-existence is essential for our well being. It also revealed that the cause of disease is not only the pathogen but the change in the equilibrium of microorganisms in the body. This knowledge has opened new avenues for diagnostic and treatment methods. This project opened a great opportunity to design personalised medicine and to arrange treatment according to each individual’s microbiome.

Question 15.
A. The quantity of urine excreted by a person in different seasons is given below. Analyse it and answer the following questions.

a) Write down the climate B and C
b) Analyse the difference shown in 13 and C and write down its reasons.
c) Which hormone is responsible for the excreation of excess water through urine.
Answer:
a) B – Rainy season or winter season,
C – Summer season

b) In rainy season production of vassopressin is less it decreases the reabsorbtion of water in the kidneys. So raises the quantity of urine. In summer season production of vasopressin increases. It increases the reabsorbtion of water in kidneys and lowers the quantity of urine.

c) ADH or vasopressin

OR
B.Choose the correct pairs related to the eye defects from the pairs given below.
a) Cataract – Reabsorption of aqueous humor does not occur
b) Glaucoma – Rectified by Replacing the lens
c) Colour blindness – Infection of conjunctiva
d) Cataract – Lens of the eye becomes opaque
e) Conjunctivitis – Rectified by Laser surgery
f) Glaucoma – Rectified by Laser surgery
g) Colour blindness – Inability to distinguish colours
Answer:
Correct pairs
d) Cataract – Lens of the eye becomes opaque
f) Glaucoma – Rectified by Laser surgery
g) Colour Blindness – Inability to distinguish colours

Question 16.
The result of a survey conducted by the Health Department on mosquito borne diseases is shown in the graph. Analyse the graph and answer the questions.

a) Which disease affects more number of people?
b) Write symptoms of the disease B.
c) Suggest suitable measures to prevent the spread of the diseases shown in the graph.
Answer:
a) Filariasis (Filarial worm).
b) Fligh fever with shivering, profuse sweating, headache, vomiting, diarrhoea, anaemia, etc.
c) Dengue fever. Malaria, and Filariasis are the diseases spread by mosquitoes. Therefore, avoid circumstances that lead to the spread of mosquitoes. Observe ‘Dry Day’ once in two weeks, keep our surroundings clean, and practice the use of measures like mosquito nets.

Question 17.
‘DNA fingerprinting and gene mapping are two important branches of biological technology. These technologies help in analysing the unique genetic information in DNA. What are the possibilities of DNA fingerprinting and gene mapping?
Answer:
DNA fingerprinting:

1. To resolve paternity disputes
2. To identify missing persons when they are later found.
3. To identify those involved in crimes

Gene mapping:

1. To understand the exact location of the genes that control each trait in the DNA.
2. To perform gene therapy by removing defective genes.
3. To create new species of organisms.

The 18th question carries 4 scores (1 × 4 = 4 scores)

Question 18.
A. Given below is an illustration showing how sex determination takes place in men.

a) Observe the illustration and examine the 4 types of possible offspring. Specify their sex chromosomes.
b) What are the inferences you arrive at from this illustration?
c) What is the probable ratio of the formation of male and female children in men?
d) Which are the sex-determining chromosomes in men?
Answer:
a) [i] and [iii] are female children having XX chro-mosomes. [ii] and [iv] are male children having XY chromosomes.

b) The sex chromosomes of a male determine the sex of a child. The probability of the formation of male and female children is almost equal [1:1].

c) 1:1

d) Sex determining chromosomes in men are X and Y.

OR
B. Select the suitable code from the indicators and write them on the basis of correct features in the given statements
Cerebrum – CRB, Cerebellum – CRL, Medulla oblongata – MOG, Hypothalamus – HYP, Thalamus – THL
Answer:
(a) It plays an important role in problem solving, planning and voluntary movements – CRB
(b) Helps to maintain equilibrium of the body by coordinating muscular activities – CRL
(c) Helps in maintaining homeostasis by regulating body temperature, hunger, thirst and emotions – HYP
(d) Controls involuntary activities like heartbeat, ventilation, vomiting, cough, sneezing etc. – MOG
(e) Acts as the relay station of messages to and from the cerebrum – THL
(f) Centre of memory, intelligence, thinking and imagination – CRB
(g) The second largest part of the brain – CRL
(h) Pain killers act on this part of the brain – THL

Practicing Physics Question Paper Class 10 Kerala Syllabus Set 5 English Medium helps identify strengths and weaknesses in a subject.

Physics Class 10 Kerala Syllabus Model Question Paper Set 5

Time: 1 1/2 Hours
Total Score: 40

Instructions:

1. The first 15 minutes is cool-off time. This time is meant for reading the questions and planning your answers.
2. This question paper includes 18 questions in sections A, B, C, D.
3. Questions 6, 9, 12, 17 and 18 contain choices.
4. You need to answer only one of the options provided for each of these choice-based questions.

Section – A

Write down the correct answer by choosing from the given options for questions 1 to 4. Each question carries 1 score. (4 × 1 = 4)

Question 1.

Identify the devices from the options given below.
a) (i) -second order lever, (ii)-Fixed pulley
b) (i) – third order lever, (ii) – Movable pulley
c) (i) – Second order lever, (ii)-Movable pulley
d) (i)- Third order lever, (ii)-Fixed pulley
Answer:
c) (i) – Second order lever, (ii)-Movable pulley

Question 2.
Find the most appropriate statement related to a telescope.
a) The objective lens has a shorter focal length and the eyepiece lens has a longer focal length.
b) The objective lens has a longer focal length and the eyepiece has a shorter focal length.
c) Objective lens and eyepiece lens are concave lenses.
d) Objective lens will be concave lens and eyepiece lens will be convex lens.
Answer:
b) The objective lens has a longer focal length and the eyepiece has a shorter focal length.

Question 3.
Statement: A current is induced in a coil when a magnet is moved towards or away from it. Reason: The relative motion between the coil and the magnet changes the magnetic flux through the coil.
a) Both statement and reason are true; the reason explains the statement.
b) Both statement and reason are true; but the reason does not explain the statement.
c) Both the statement and the reason are incorrect.
d) Statement is incorrect; reason is correct.
Answer:
a) Both statement and reason are true; the reason explains the statement.

Question 4.
Some statements related to electrical power is given.
i. Electric power is measured in joules.
ii. 1 kilowatt-hour is equal to 1000 joules.
iii. Power is the quantity of work done by an electrical appliance per unit time.
iv. Power, P = y

Which are the correct statements related to it.
a) i and ii only
b) iii and iv only
c) ivonly
d) iii only
Answer:
d) iii only

Section – B

Write down the answers to the questions 5 to 11. Questions 6 and 9 have choices. Each question carries 2 score. (7 × 2 = 14)

Question 5.
The primary and secondary currents of a transformer are 2 A and 4 A respectively. The output voltage of this transformer is 100 V.
a) Identify the transformer.
b) Calculate the primary voltage of the transformer.
Answer:
a) Stepdown Transformer
b) V_p × I_p = V_s × I_s
∴ V_p = (V_s × I_s)/I_p
= (100 × 4)/2
= 200 V

Question 6.
(a) A conductor is held above and parallel to a magntic needle.

a) What causes the magnetic needle to deflect when the switch is turned on?
b) Suggest two ways to reverse the direction of this deflection.
Answer:
a) A magnetic field is formed around a current carrying conductor. This magnetic field can exert a force on a magnetic needle. The magnetic needle was deflected due to the interaction between this magnetic field and the magnetic field around the magnetic needle.

b) • Change the direction of current
• Arrange the conductor below the compass needle

OR
Question 6.

The magnetic field of which magnets are depicted? Explain.
Answer:
a) Bar magnet
b) Electromagnet (solenoid)
The magnetic field lines of the bar magnet and that of the electromagnet are similar. The magnetic strength / magnetism of an electromagnet is temporary and that of a bar magnet is permanent.

Question 7.
Match correctly

Sound Board	Resonance
Resonance Column	Period
Characteristic of wave	Richter scale
Intensity of earthquake	Reflection of sound

Answer:

Sound Board	Reflection of sound
Resonance Column	Resonance
Characteristic of wave	Period
Intensity of earthquake	Richter scale

Question 8.
Complete the following sentences
a) The lens that forms only virtual images is …… (convex lens, concave lens)
b) In a telescope, the objective forms a ……. image of a distant object (small, real and inverted ; magnified, real and inverted)
Answer:
a) concave lens
b) small, real and inverted

Question 9.
(A).a)Name the part of a heating equipment in which the electric energy is converted into heat energy,
b) Name the substance used to make this part.
Answer:
a) Heating coil
b) Nichrome

OR
(B) In a house, 5 CF lamps each of 20 W work for 4 hours, and 4 fans each of 60 W work for 5 hours in a day. What will be the daily consumption of energy shown by the watt-hour meter?
Answer:
Electric energy (in kilowatt hour)
= \(\frac{\text { Power in watt × time in hour }}{1000}\)
Energy consumed by 5 CF lamps
= \(\frac{5 \times 20 \times 4}{1000}\) = 0.4k Wh
Energy consumed by 4 fans
\(\frac{4 \times 60 \times 5}{1000}\) = 1.2 kWh
Daily consumption of energy
= 0.4 + 1.2 = 1.6 kWh = 1.6 kWh

Question 10.
Explain the necessity of gears in vehicles.
Answer:
While going uphill, large wheel is connected to the toothed wheel attached to the engine. When connected to a large toothed wheel, the speed of the vehicle decreases, but its efficiency to rotate increases. To increase the speed of the vehicle, the toothed wheel attached to the engine must be connected to the small toothed wheel that helps to turn the tyre of the vehicle.

Question 11.
Safety must be ensured while working with electric circuits. There are many situations which may lead to an electric shock.
a) What do you mean by electric shock?
b) Write any two first aid measures that should be given to a person who has suffered an electric shock.
Answer:
a) Electric shock is the impact caused by the flow of current through the body,

b) • Rub the body to increase blood circulation and raise body temperature.
• Administer artificial respiration.
• Rub the muscles to restore them to their normal state.
• Start first aid to restart the heart-perform chest compressions rhythmically and forcefully (Cardio Pulmonary Resuscitation).
(any two)

Section – C

Write down the answers to questions 12 to 17. Questions 12 and 17 have choices. Each question carries 3 score. (6 × 3 = 18)

Question 12.
(A). Inclined planes are often used in situations where objects are to be lifted.
a) What is the work done to lift a 600 N load by 3m?
b) The force applied was 200 N along an inclined plane to lift this load. Displacement of the load was 9 m. What is the work done?
c) Is there a gain in the work done?
Answer:
a) Force, F = 600 N
Displacement, s = 3 m
4rork done, W = Fs
= 600 × 3 = 1800 Nm = 1800J

b) Force, F = 200N
Displacement. s = 9m
Work done, W = 200 × 9 = 1800 Nm = 1800 J

c) There is no gain in work done.

OR
(B). a) A load of 1600 kgwt is suspended from an axle with a diameter of 6 cm. What should be the force applied in newton, to turn a 3 m long lever on one side of the axle, to lift this load? (Consider g = 10 m/s²)
b) In a wheel and axle system ,what happens to the mechanical advantage when radius of wheel increases.
Answer:
a)Mechanical advantage of axle and wheel
= (R/r) = (L/E)
Diameter of the axle = 6 cm
Radius of the axle, r = 3 cm
Load = L = 1600 kgwt
= 1600 × 10 N = 16000 N
Radius of the wheel, R = 300 cm
(L/E) = (R/r)
(16000/E) = (300/3)
Effort, E = 160N

b) As the radius of the wheel increases, the mechanical advantage also increases.

Question 13.
a) If an ultrasonic wave emitted by a transmitter, installed on a ship on the surface of the water, strikes a rock at the bottom of the sea and returns after 0.2 s, what is the distance from the ship to the rock? Consider the speed of ultrasonic waves in seawater as 1522 m/s.
b) Bats make use of ______ sounds for catching prey
Answer:
(a) v = 1522 m/s
t = 0.2s
v = 2d/t
2d = v × t
d = (v × t)/2 = (1522 × 0.2)/2 = 152.2m

(b) UItrasonic

Question 14.
The focal length of a convex lens is 20 cm. An object of height 2 cm is placed on its optic axis is located 40 cm away from the lens. Calculate the distance from the lens to the image. What will be the magnification in this case? What are the characteristics of the image formed?
Answer:
f = 20 cm
h₀ = 2 cm
The object is located at 2f (at 40 cm) of the convex lens. Here, the distance from the lens to the image v = 40 cm.
Magnification = -1
Characteristics of the image: same size, inverted, real

Question 15.
Observe the figure

When the current is from A to B, in which direction does the north pole of each magnetic needle deflect? (Clockwise direction/anticlock wise direction)
Answer:
a) Anticlockwise direction
b) Right hand thumb rule
c) Imagine holding a conductor with your right hand in such a way that the thumb points in the direction of the electric current, the fingers curled around the conductor will indicate the direction of the magnetic field.

Question 16.
Observe the figure.

a) If the magnet is rapidly moved into the coil, what will you observe in the galvanometer?
b) What will be the nature of the current obtained if the magnet is rapidly moved up and down inside the coil?
c) What are the ways to increase the current induced in the coil?
Answer:
a) The galvanometer needle will deflect.

b) The current will be alternating (changes direction).

c) • Moving the magnet faster
• Using a stronger magnet
• Using more turns of wire in the coil

Question 17.
(A) Observe the figure given below and answer the following

a) Which are the occasions when sunlight has to travel greater distance through the atmosphere before reaching the eyes of an observer on the earth?
b) When light reaches the observer after travelling long distances through the atmosphere, which colour reaches the eye? What is the reason?
c) Even after sunset, the western horizon continues to have red colour for some more time. Why?
Answer:
a) In the morning and in the evening sunlight has to travel greater distance.

b) Red. Due to its greater wavelength.

c) During long distant travelling of sunlight, light travels through more of the Earth’s atmosphere. As it does, the shorter blue wavelengths scatter more, leaving the longer wavelength (red)for us to see.That is colours of shorter wavelength would be almost fully lost due to scattering and only red will predominate.

OR
(B) Observe the images related to image formation in the eyes.

a) Which is the image showing an eye with nears ightedness?
b) What are the reasons behind near-sightedness?
c) What is the remedy for this defect?
Answer:
a) B
b) • The size of the eye ball is larger.
• The focal length of the eye lens is low (power high)
c) This can be overcome by using concave lens of suitable power.

Section – D

18th question has a choice. Answer any one of the two questions. Each question carries 4 score. (4 × 1 = 4)

Question 18.
(A). An electric heater of 1000 £1 works on a 230 V supply
a) Write down the energy change taking place in the electric heater.
b) State the law to find the quantity of heat generated in an electric heater?
c) Calculate the electrical energy consumed when the heater works for three hours.
Answer:
A.a) Electrical energy is converted to heat energy
b) The quantity of heat produced in a current carrying conductor is directly proportional to the square of the current (P), the resistance of the conductor (R) and the time (t) for which the current flows. This is Joule’s law.
c) V = 230 V,
R = 1000Q,
t = 3 hour = 3 x 60 × 60 = 10800 s
H = \(\frac{v^2 t}{R}=\frac{230^2 \times 10800}{1000}\) = 571320 J

OR
(B), Observe the figure.

a) Write down the name of the device.
b) What is it used for?
c) In a house 5 LED lamps each of 20 W works for 5 hours and one laptop of 50 W works for 2 hours daily. Calculate electrical energy consumption in one month in commercial units.
Answer:
a) Watt-hour meter
b) The quantity of electric energy consumed in houses can be measured directly by a watt hour meter.
c) Electric energy (in kilowatt hour)
= [/latex]\frac{\text { Power in watt × time in hour }}{1000}[/latex]
Electric energy consumed by lamps
= \(\frac{5 \times 20 \times 4}{1000}\) = 0.5 units
Electric energy consumed by laptop
\( \frac{4 \times 60 \times 5}{1000} \) = 0.1 units
Total energy consumption in a day
= 0.5 + 0.1 = 0.6 units
Total energy consumption in a month
= 0.6 × 30 = 18 units