This is the complete solved model question paper for Bihar Board (BSEB) Class 10 Science Annual Examination 2026, prepared strictly according to the latest syllabus and examination pattern issued by Bihar School Examination Board. The paper consists of 80 objective-type questions (Section-A) carrying 1 mark each (answer any 40) and 24 subjective questions (Section-B) that include 8 short-answer questions (2 marks each), and 2 long-answer questions (5 marks each) from Physics, Chemistry, and Biology sections.
Note: Long answer question of physics is of 6 marks.
This solved model paper is designed to help students understand the exact question pattern, marking scheme, and the level of difficulty expected in the 2026 board examination. All answers are accurate, concise, and written in simple language as required in the board exam. Regular practice with this model paper will boost confidence, improve time management, and ensure excellent performance in the BSEB Matric Science Exam 2026.
Best wishes for your board examination!
Keep revising and stay ahead.
Note: Long answer question of physics is of 6 marks.
This solved model paper is designed to help students understand the exact question pattern, marking scheme, and the level of difficulty expected in the 2026 board examination. All answers are accurate, concise, and written in simple language as required in the board exam. Regular practice with this model paper will boost confidence, improve time management, and ensure excellent performance in the BSEB Matric Science Exam 2026.
Best wishes for your board examination!
Keep revising and stay ahead.
Section-A / Objective Type Questions
Questions Nos. 1 to 80 are of objective type. Answer any 40 questions. Each question has four options, out of which only one is correct. You have to mark your selected option on the OMR sheet. 40 x 1 = 40
Section-B / Physics / Short Answer Type Questions
Question Nos 1 to 8 are short Answer Type. Answer any 4 questions. Each question carries 2 marks.4 x 2 = 8
Q.1 What is magnification? Describe it.
Answer:
Magnification is the ratio of the height (or size) of the image formed by a mirror or lens to the height (or size) of the object. It tells how many times the image is larger or smaller than the object.
Formula: Magnification (m) = (Height of image (hᵢ)) / (Height of object (hₒ)) = - (v/u)
If |m| > 1 → image is enlarged; if |m| < 1 → image is diminished; negative sign indicates inverted image.
Magnification is the ratio of the height (or size) of the image formed by a mirror or lens to the height (or size) of the object. It tells how many times the image is larger or smaller than the object.
Formula: Magnification (m) = (Height of image (hᵢ)) / (Height of object (hₒ)) = - (v/u)
If |m| > 1 → image is enlarged; if |m| < 1 → image is diminished; negative sign indicates inverted image.
Q.2 Why is concave lens called a diverging lens?
Answer:
A concave lens is called a diverging lens because it causes parallel rays of light passing through it to spread out (diverge) after refraction, as if they are coming from a single point (virtual focus) on the same side of the lens.
A concave lens is called a diverging lens because it causes parallel rays of light passing through it to spread out (diverge) after refraction, as if they are coming from a single point (virtual focus) on the same side of the lens.
Q.3 What do you mean by lateral displacement?
Answer:
Lateral displacement is the perpendicular distance between the incident ray and the emergent ray when a ray of light passes through a glass slab (or parallel-sided transparent medium). It occurs due to refraction and depends on the thickness of the slab, angle of incidence, and refractive index.
Lateral displacement is the perpendicular distance between the incident ray and the emergent ray when a ray of light passes through a glass slab (or parallel-sided transparent medium). It occurs due to refraction and depends on the thickness of the slab, angle of incidence, and refractive index.
Q.4 Define the strength of electric current.
Answer:
The strength of electric current (or simply electric current) is defined as the amount of electric charge flowing through a conductor per unit time. It is measured in amperes (A).
I = Q/t (where Q is charge in coulombs, t is time in seconds).
The strength of electric current (or simply electric current) is defined as the amount of electric charge flowing through a conductor per unit time. It is measured in amperes (A).
I = Q/t (where Q is charge in coulombs, t is time in seconds).
Q.5 On which factors does the heating effect of electric current depend?
Answer:
The heating effect of electric current (Joule heating) depends on three factors:
1. The amount of current (I) flowing through the conductor.
2. The resistance (R) of the conductor.
3. The time (t) for which the current flows.
Heat produced, H = I²Rt.
The heating effect of electric current (Joule heating) depends on three factors:
1. The amount of current (I) flowing through the conductor.
2. The resistance (R) of the conductor.
3. The time (t) for which the current flows.
Heat produced, H = I²Rt.
Q.6 What is electromagnetic induction?
Answer:
Electromagnetic induction is the phenomenon of production of induced electromotive force (emf) and hence induced current in a coil when the magnetic flux linked with the coil changes with time. It was discovered by Michael Faraday.
Electromagnetic induction is the phenomenon of production of induced electromotive force (emf) and hence induced current in a coil when the magnetic flux linked with the coil changes with time. It was discovered by Michael Faraday.
Q.7 Write Maxwell's right-hand rule.
Answer:
Maxwell's right-hand thumb rule (or Fleming's right-hand rule for generators): Stretch the thumb, forefinger, and middle finger of the right hand mutually perpendicular to each other. If the thumb points in the direction of motion of the conductor, the forefinger points in the direction of the magnetic field, then the middle finger will point in the direction of induced current.
Maxwell's right-hand thumb rule (or Fleming's right-hand rule for generators): Stretch the thumb, forefinger, and middle finger of the right hand mutually perpendicular to each other. If the thumb points in the direction of motion of the conductor, the forefinger points in the direction of the magnetic field, then the middle finger will point in the direction of induced current.
Q.8 What is a good source of energy?
Answer:
A good source of energy is one that:
1. Provides a large amount of energy per unit mass or volume.
2. Is easily accessible, easy to store and transport.
3. Is economical and environment-friendly (causes least pollution).
Examples: Solar energy, wind energy, hydroelectric energy.
A good source of energy is one that:
1. Provides a large amount of energy per unit mass or volume.
2. Is easily accessible, easy to store and transport.
3. Is economical and environment-friendly (causes least pollution).
Examples: Solar energy, wind energy, hydroelectric energy.
Section-B / Physics / Long Answer Type Questions
Question Nos 09 and 10 are Long Answer Type. Answer any one of them. Each question carries 6 marks.1 x 6 = 6
Q.9 With the help of ray diagrams, explain the first and second principal focus of convex and concave lenses.
Answer:
Convex Lens (Converging Lens):
1. First Principal Focus (F1): It is the point on the principal axis from where rays of light, initially parallel to the principal axis, after refraction through the lens, converge to a point (real focus) on the other side.
(For distant objects, image is formed at F1.)
2. Second Principal Focus (F2): It is the point on the principal axis to which rays of light coming from this point, after refraction through the lens, become parallel to the principal axis.
(Object placed at F2 forms image at infinity.)
Focal length f is positive.
Ray Diagrams (Convex Lens): First focus: Parallel rays → converge at F (on the other side). Second focus: Rays from F → emerge parallel to principal axis. Concave Lens (Diverging Lens):
1. First Principal Focus (F1): It is the point on the principal axis from where rays of light, initially parallel to the principal axis, after refraction appear to diverge from a point (virtual focus) on the same side.
2. Second Principal Focus (F2): It is the point on the principal axis to which rays directed towards it, after refraction, become parallel to the principal axis (virtual, on the same side).
Focal length f is negative.
Ray Diagrams (Concave Lens): First focus: Parallel rays → diverge, appear to come from F (same side). Second focus: Rays directed towards F → emerge parallel. (Note: In diagrams, dotted lines are drawn backwards for virtual rays in concave lens.)
Convex Lens (Converging Lens):
1. First Principal Focus (F1): It is the point on the principal axis from where rays of light, initially parallel to the principal axis, after refraction through the lens, converge to a point (real focus) on the other side.
(For distant objects, image is formed at F1.)
2. Second Principal Focus (F2): It is the point on the principal axis to which rays of light coming from this point, after refraction through the lens, become parallel to the principal axis.
(Object placed at F2 forms image at infinity.)
Focal length f is positive.
Ray Diagrams (Convex Lens): First focus: Parallel rays → converge at F (on the other side). Second focus: Rays from F → emerge parallel to principal axis. Concave Lens (Diverging Lens):
1. First Principal Focus (F1): It is the point on the principal axis from where rays of light, initially parallel to the principal axis, after refraction appear to diverge from a point (virtual focus) on the same side.
2. Second Principal Focus (F2): It is the point on the principal axis to which rays directed towards it, after refraction, become parallel to the principal axis (virtual, on the same side).
Focal length f is negative.
Ray Diagrams (Concave Lens): First focus: Parallel rays → diverge, appear to come from F (same side). Second focus: Rays directed towards F → emerge parallel. (Note: In diagrams, dotted lines are drawn backwards for virtual rays in concave lens.)
Q.10 Obtain expression for the equivalent resistance of resistors connected in series and resistors connected in parallel.
Answer:
1. Resistors in Series:
When resistors are connected end-to-end, the same current (I) flows through each resistor, but potential difference is divided.
Let resistances be R1, R2, R3.
Total potential difference V = V1 + V2 + V3
By Ohm's law: V1 = IR1, V2 = IR2, V3 = IR3
∴ V = I(R1 + R2 + R3)
If Rs is equivalent resistance, then V = IRₛ
∴ IRs = I(R1 + R2 + R3)
⇒ Rs = Rv + R2 + R3
Result: In series combination, equivalent resistance is the sum of individual resistances.
2. Resistors in Parallel:
When resistors are connected across the same two points, potential difference (V) across each is same, but current is divided.
Let resistances be R1, R2, R3.
Total current I = I1 + I2 + I3
By Ohm’s law: I1 = V/R1, I2 = V/R2, I3 = V/R3
∴ I = V (1/R1 + 1/R2 + 1/R3)
If Rp is equivalent resistance, then I = V/Rp
∴ V/Rp = V (1/R1 + 1/R2 + 1/R3)
⇒ 1/Rp = 1/R1 + 1/R2 + 1/R3
Result: In parallel combination, the reciprocal of equivalent resistance is the sum of reciprocals of individual resistances.
(For two resistors: 1/Rp = 1/R1 + 1/R2 ⇒ Rp = R1R2/(R1 + R2))
1. Resistors in Series:
When resistors are connected end-to-end, the same current (I) flows through each resistor, but potential difference is divided.
Let resistances be R1, R2, R3.
Total potential difference V = V1 + V2 + V3
By Ohm's law: V1 = IR1, V2 = IR2, V3 = IR3
∴ V = I(R1 + R2 + R3)
If Rs is equivalent resistance, then V = IRₛ
∴ IRs = I(R1 + R2 + R3)
⇒ Rs = Rv + R2 + R3
Result: In series combination, equivalent resistance is the sum of individual resistances.
2. Resistors in Parallel:
When resistors are connected across the same two points, potential difference (V) across each is same, but current is divided.
Let resistances be R1, R2, R3.
Total current I = I1 + I2 + I3
By Ohm’s law: I1 = V/R1, I2 = V/R2, I3 = V/R3
∴ I = V (1/R1 + 1/R2 + 1/R3)
If Rp is equivalent resistance, then I = V/Rp
∴ V/Rp = V (1/R1 + 1/R2 + 1/R3)
⇒ 1/Rp = 1/R1 + 1/R2 + 1/R3
Result: In parallel combination, the reciprocal of equivalent resistance is the sum of reciprocals of individual resistances.
(For two resistors: 1/Rp = 1/R1 + 1/R2 ⇒ Rp = R1R2/(R1 + R2))
Section-B / Chemistry / Short Answer Type Questions
Question Nos 11 to 18 are short Answer Type. Answer any 4 questions. Each question carries 2 marks.4 x 2 = 8
Q.11 What is a combination reaction?
Answer:
A combination reaction is a type of chemical reaction where two or more reactants combine to form a single product. It is also known as a synthesis reaction. For example, the reaction between hydrogen and oxygen to form water: 2H2 + O2 → 2H2O.
A combination reaction is a type of chemical reaction where two or more reactants combine to form a single product. It is also known as a synthesis reaction. For example, the reaction between hydrogen and oxygen to form water: 2H2 + O2 → 2H2O.
Q.12 What is rancidity? Explain with examples.
Answer:
Rancidity is the process of oxidation of fats and oils present in food items, leading to unpleasant smell and taste, making the food unfit for consumption. It occurs when food is exposed to air, moisture, or light.
Examples:
1. Potato chips left open in air become rancid due to oxidation of oils.
2. Butter or ghee kept for a long time develops a bad odor because of rancidity.
Rancidity is the process of oxidation of fats and oils present in food items, leading to unpleasant smell and taste, making the food unfit for consumption. It occurs when food is exposed to air, moisture, or light.
Examples:
1. Potato chips left open in air become rancid due to oxidation of oils.
2. Butter or ghee kept for a long time develops a bad odor because of rancidity.
Q.13 How is sodium carbonate used to soften salty water?
Answer:
Salty water or hard water contains soluble salts of calcium and magnesium. Sodium carbonate (washing soda) is added to hard water to soften it. It reacts with the calcium and magnesium ions to form insoluble carbonates (CaCO3 and MgCO3), which precipitate out, thus removing the hardness. For example: Ca²⁺ + Na2CO3 → CaCO3 ↓ + 2Na⁺.
Salty water or hard water contains soluble salts of calcium and magnesium. Sodium carbonate (washing soda) is added to hard water to soften it. It reacts with the calcium and magnesium ions to form insoluble carbonates (CaCO3 and MgCO3), which precipitate out, thus removing the hardness. For example: Ca²⁺ + Na2CO3 → CaCO3 ↓ + 2Na⁺.
Q.14 Distilled water is not a conductor of electricity, whereas rain water is a conductor of electricity. why?
Answer:
Distilled water is pure water and does not contain any dissolved salts or ions, so it does not conduct electricity as there are no free ions to carry the charge. Rain water, on the other hand, dissolves gases like carbon dioxide from the atmosphere, forming carbonic acid (H2CO3), which dissociates into ions (H⁺ and HCO3⁻), making it a conductor of electricity.
Distilled water is pure water and does not contain any dissolved salts or ions, so it does not conduct electricity as there are no free ions to carry the charge. Rain water, on the other hand, dissolves gases like carbon dioxide from the atmosphere, forming carbonic acid (H2CO3), which dissociates into ions (H⁺ and HCO3⁻), making it a conductor of electricity.
Q.15 What is the process of roasting?
Answer:
Roasting is a metallurgical process in which a sulphide ore is heated strongly in the presence of excess air to convert it into its oxide form. This process removes volatile impurities and moisture from the ore.
For example, roasting of zinc sulphide:
2ZnS + 3O2 → 2ZnO + 2SO2.
Roasting is a metallurgical process in which a sulphide ore is heated strongly in the presence of excess air to convert it into its oxide form. This process removes volatile impurities and moisture from the ore.
For example, roasting of zinc sulphide:
2ZnS + 3O2 → 2ZnO + 2SO2.
Q.16 Write the structural formulae and names of the isomers of pentane.
Answer:
Pentane (C5H12) has three isomers:
1. n-Pentane: CH3-CH2-CH2-CH2-CH3 (straight chain).
2. Isopentane (2-Methylbutane): CH3-CH(CH3)-CH2-CH3.
3. Neopentane (2,2-Dimethylpropane): (CH3)4C or CH3-C(CH3)-CH3.
Pentane (C5H12) has three isomers:
1. n-Pentane: CH3-CH2-CH2-CH2-CH3 (straight chain).
2. Isopentane (2-Methylbutane): CH3-CH(CH3)-CH2-CH3.
3. Neopentane (2,2-Dimethylpropane): (CH3)4C or CH3-C(CH3)-CH3.
Q.17 Why do metals have a tendency to lose electrons and form cations?
Answer:
Metals have 1 to 3 valence electrons in their outermost shell and low ionization energy. They tend to lose these electrons to achieve a stable noble gas electronic configuration, forming positively charged cations. This loss of electrons is easier for metals due to their larger atomic size and weaker nuclear hold on valence electrons.
Metals have 1 to 3 valence electrons in their outermost shell and low ionization energy. They tend to lose these electrons to achieve a stable noble gas electronic configuration, forming positively charged cations. This loss of electrons is easier for metals due to their larger atomic size and weaker nuclear hold on valence electrons.
Q.18 Mention various measures for conservation of wildlife.
Answer:
Measures for wildlife conservation include:
1. Establishing protected areas like national parks, wildlife sanctuaries, and biosphere reserves.
2. Enforcing strict laws against poaching, hunting, and illegal trade of wildlife products.
3. Promoting afforestation and habitat restoration to prevent deforestation.
4. Raising public awareness through education and campaigns about the importance of wildlife.
Measures for wildlife conservation include:
1. Establishing protected areas like national parks, wildlife sanctuaries, and biosphere reserves.
2. Enforcing strict laws against poaching, hunting, and illegal trade of wildlife products.
3. Promoting afforestation and habitat restoration to prevent deforestation.
4. Raising public awareness through education and campaigns about the importance of wildlife.
Section-B / Chemistry / Long Answer Type Questions
Question Nos 19 and 20 are Long Answer Type. Answer any one of them. Each question carries 5 marks.1 x 5 = 5
Q.19 What are natural indicators? How are acids and bases tested with them?
Answer:
Natural indicators are substances obtained from natural sources that change color when exposed to acids or bases, helping to identify whether a solution is acidic or basic. They are derived from plants, animals, or minerals. Common examples include litmus (extracted from lichens), turmeric (from the root of the turmeric plant), red cabbage juice, and beetroot extract.
How acids and bases are tested with them:
1. Litmus: Blue litmus paper turns red in acidic solutions (pH < 7) and remains blue in basic solutions. Red litmus paper turns blue in basic solutions (pH > 7) and remains red in acidic solutions. Neutral solutions (pH = 7) do not change the color of either.
2. Turmeric: Turmeric solution or paper is yellow in acidic or neutral solutions but turns reddish-brown in basic solutions due to the presence of curcumin.
3. Red Cabbage Juice: It turns red in strong acids, pink in weak acids, green in weak bases, and blue in strong bases. Neutral solutions keep it purple.
4. Beetroot Extract: It turns pink-red in acids and yellow in bases.
These indicators work based on the pH-dependent color change of their pigments, allowing simple visual testing without equipment.
Natural indicators are substances obtained from natural sources that change color when exposed to acids or bases, helping to identify whether a solution is acidic or basic. They are derived from plants, animals, or minerals. Common examples include litmus (extracted from lichens), turmeric (from the root of the turmeric plant), red cabbage juice, and beetroot extract.
How acids and bases are tested with them:
1. Litmus: Blue litmus paper turns red in acidic solutions (pH < 7) and remains blue in basic solutions. Red litmus paper turns blue in basic solutions (pH > 7) and remains red in acidic solutions. Neutral solutions (pH = 7) do not change the color of either.
2. Turmeric: Turmeric solution or paper is yellow in acidic or neutral solutions but turns reddish-brown in basic solutions due to the presence of curcumin.
3. Red Cabbage Juice: It turns red in strong acids, pink in weak acids, green in weak bases, and blue in strong bases. Neutral solutions keep it purple.
4. Beetroot Extract: It turns pink-red in acids and yellow in bases.
These indicators work based on the pH-dependent color change of their pigments, allowing simple visual testing without equipment.
Q.20 Differentiate between metals and nonmetals on the basis of physical and chemical properties.
Answer:
Metals and nonmetals are two main categories of elements differentiated by their physical and chemical properties. Below is a comparison:
Physical Properties:
1. Appearance: Metals are generally lustrous (shiny) when polished, e.g., gold, silver. Nonmetals are dull (non-lustrous), e.g., sulfur, phosphorus (exception: iodine is lustrous).
2. Malleability and Ductility: Metals are malleable (can be hammered into sheets) and ductile (can be drawn into wires), e.g., copper, aluminum. Nonmetals are brittle and break easily when hammered, e.g., carbon, sulfur.
3. Conductivity: Metals are good conductors of heat and electricity due to free electrons, e.g., silver, copper. Nonmetals are poor conductors (insulators), e.g., rubber, plastic (exception: graphite is a good conductor).
4. Density and Melting/Boiling Points: Metals have high density and high melting/boiling points, e.g., iron. Nonmetals have low density and low melting/boiling points, e.g., oxygen, nitrogen (exception: diamond has high melting point).
5. State at Room Temperature: Most metals are solid (exception: mercury is liquid). Nonmetals can be solid (sulfur), liquid (bromine), or gas (oxygen).
Chemical Properties:
1. Reactivity with Oxygen: Metals form basic oxides, e.g., Na₂O (sodium oxide) is basic. Nonmetals form acidic oxides, e.g., CO2 (carbon dioxide) is acidic.
2. Electron Tendency: Metals lose electrons to form cations (positive ions), showing electropositive nature, e.g., Na → Na⁺ + e⁻. Nonmetals gain electrons to form anions (negative ions), showing electronegative nature, e.g., Cl + e⁻ → Cl⁻.
3. Reactivity with Acids: Metals react with acids to produce hydrogen gas, e.g., Zn + 2HCl → ZnCl2 + H2. Nonmetals do not react with acids (exception: some like sulfur react under specific conditions).
4. Reactivity with Water: Reactive metals displace hydrogen from water, e.g., 2Na + 2H2O → 2NaOH + H2. Nonmetals do not react with water in this way.
Metals and nonmetals are two main categories of elements differentiated by their physical and chemical properties. Below is a comparison:
Physical Properties:
1. Appearance: Metals are generally lustrous (shiny) when polished, e.g., gold, silver. Nonmetals are dull (non-lustrous), e.g., sulfur, phosphorus (exception: iodine is lustrous).
2. Malleability and Ductility: Metals are malleable (can be hammered into sheets) and ductile (can be drawn into wires), e.g., copper, aluminum. Nonmetals are brittle and break easily when hammered, e.g., carbon, sulfur.
3. Conductivity: Metals are good conductors of heat and electricity due to free electrons, e.g., silver, copper. Nonmetals are poor conductors (insulators), e.g., rubber, plastic (exception: graphite is a good conductor).
4. Density and Melting/Boiling Points: Metals have high density and high melting/boiling points, e.g., iron. Nonmetals have low density and low melting/boiling points, e.g., oxygen, nitrogen (exception: diamond has high melting point).
5. State at Room Temperature: Most metals are solid (exception: mercury is liquid). Nonmetals can be solid (sulfur), liquid (bromine), or gas (oxygen).
Chemical Properties:
1. Reactivity with Oxygen: Metals form basic oxides, e.g., Na₂O (sodium oxide) is basic. Nonmetals form acidic oxides, e.g., CO2 (carbon dioxide) is acidic.
2. Electron Tendency: Metals lose electrons to form cations (positive ions), showing electropositive nature, e.g., Na → Na⁺ + e⁻. Nonmetals gain electrons to form anions (negative ions), showing electronegative nature, e.g., Cl + e⁻ → Cl⁻.
3. Reactivity with Acids: Metals react with acids to produce hydrogen gas, e.g., Zn + 2HCl → ZnCl2 + H2. Nonmetals do not react with acids (exception: some like sulfur react under specific conditions).
4. Reactivity with Water: Reactive metals displace hydrogen from water, e.g., 2Na + 2H2O → 2NaOH + H2. Nonmetals do not react with water in this way.
Section-B / Biology / Short Answer Type Questions
Question Nos 21 to 28 are short Answer Type. Answer any 4 questions. Each question carries 2 marks. 4 x 2 = 8
Q.21 What are villi and what is their function?
Answer:
Villi are small, finger-like projections present on the inner lining of the small intestine. Their main function is to increase the surface area for the absorption of digested nutrients from food into the bloodstream. They contain blood vessels and lacteals that help in transporting absorbed nutrients.
Villi are small, finger-like projections present on the inner lining of the small intestine. Their main function is to increase the surface area for the absorption of digested nutrients from food into the bloodstream. They contain blood vessels and lacteals that help in transporting absorbed nutrients.
Q.22 What are stomata and where are they present?
Answer:
Stomata are tiny pores or openings found on the surface of leaves and young stems of plants. They are primarily present on the lower epidermis of leaves but can also be found on the upper epidermis in some plants. Stomata are guarded by guard cells and facilitate gas exchange (CO2 intake and O2 release) and transpiration.
Stomata are tiny pores or openings found on the surface of leaves and young stems of plants. They are primarily present on the lower epidermis of leaves but can also be found on the upper epidermis in some plants. Stomata are guarded by guard cells and facilitate gas exchange (CO2 intake and O2 release) and transpiration.
Q.23 How are metabolic wastes removed in unicellular organisms?
Answer:
In unicellular organisms like Amoeba or Paramecium, metabolic wastes such as ammonia, carbon dioxide, and excess water are removed by simple diffusion through the cell membrane into the surrounding environment. Some organisms, like Paramecium, also use contractile vacuoles to expel excess water.
In unicellular organisms like Amoeba or Paramecium, metabolic wastes such as ammonia, carbon dioxide, and excess water are removed by simple diffusion through the cell membrane into the surrounding environment. Some organisms, like Paramecium, also use contractile vacuoles to expel excess water.
Q.24 What is dialysis?
Answer:
Dialysis is a medical process used to remove waste products, excess salts, and toxins from the blood when the kidneys fail to function properly. It involves passing the blood through a dialysis machine (artificial kidney) where it is filtered across a semi-permeable membrane, mimicking the kidney's function.
Dialysis is a medical process used to remove waste products, excess salts, and toxins from the blood when the kidneys fail to function properly. It involves passing the blood through a dialysis machine (artificial kidney) where it is filtered across a semi-permeable membrane, mimicking the kidney's function.
Q.25 What are roles of androecium and gynoecium?
Answer:
Androecium is the male reproductive part of a flower, consisting of stamens, and its role is to produce pollen grains (male gametes) for fertilization. Gynoecium is the female reproductive part, consisting of carpels (pistil), and its role is to produce ovules (female gametes) and provide a site for fertilization and seed development.
Androecium is the male reproductive part of a flower, consisting of stamens, and its role is to produce pollen grains (male gametes) for fertilization. Gynoecium is the female reproductive part, consisting of carpels (pistil), and its role is to produce ovules (female gametes) and provide a site for fertilization and seed development.
Q.26 What is neurotransmitter?
Answer:
A neurotransmitter is a chemical substance released at the end of a nerve fiber (synapse) that transmits nerve impulses from one neuron to another or to a muscle or gland cell. Examples include acetylcholine, dopamine, and serotonin, which help in signal transmission in the nervous system.
A neurotransmitter is a chemical substance released at the end of a nerve fiber (synapse) that transmits nerve impulses from one neuron to another or to a muscle or gland cell. Examples include acetylcholine, dopamine, and serotonin, which help in signal transmission in the nervous system.
Q.27 What do you understand by homologous organs and analogous organs?
Answer:
Homologous organs are organs that have similar basic structure and origin but perform different functions, indicating common ancestry (e.g., forelimbs of humans and wings of bats). Analogous organs have different structures and origins but perform similar functions due to convergent evolution (e.g., wings of birds and insects).
Homologous organs are organs that have similar basic structure and origin but perform different functions, indicating common ancestry (e.g., forelimbs of humans and wings of bats). Analogous organs have different structures and origins but perform similar functions due to convergent evolution (e.g., wings of birds and insects).
Q.28 What do you mean by producer?
Answer:
Producers are organisms that can synthesize their own food from inorganic substances using energy from the sun (photosynthesis) or chemicals (chemosynthesis). They form the base of the food chain and include green plants, algae, and some bacteria, which convert energy into organic matter.
Producers are organisms that can synthesize their own food from inorganic substances using energy from the sun (photosynthesis) or chemicals (chemosynthesis). They form the base of the food chain and include green plants, algae, and some bacteria, which convert energy into organic matter.
Section-B / Biology / Long Answer Type Questions
Question Nos 29 and 30 are Long Answer Type. Answer any one of them. Each question carries 5 marks. 1 x 5 = 5
Q.29 What is nutrition? Describe the different modes of nutrition found in living organisms.
Answer:
Nutrition is the process by which living organisms obtain and utilize food materials to get energy, for growth, repair, and maintenance of the body.
There are two main modes of nutrition:
1. Autotrophic Nutrition: Organisms prepare their own food from simple inorganic substances like CO₂ and water using sunlight or chemical energy.
Example: Green plants (photosynthesis), some bacteria (chemosynthesis).
Process in plants: 6CO2 + 6H2O → C6H12O6 + 6O2 (in presence of sunlight and chlorophyll).
2. Heterotrophic Nutrition: Organisms cannot make their own food and depend directly or indirectly on autotrophs for food.
Types:
Holozoic: Ingestion of solid food (e.g., humans, Amoeba).
Saprophytic: Absorption of nutrients from dead organic matter (e.g., fungi, some bacteria).
Parasitic: Living on or inside another organism and deriving food from it (e.g., tapeworm, Cuscuta).
Symbiotic: Mutual benefit between two organisms (e.g., lichens – algae and fungi).
Nutrition is the process by which living organisms obtain and utilize food materials to get energy, for growth, repair, and maintenance of the body.
There are two main modes of nutrition:
1. Autotrophic Nutrition: Organisms prepare their own food from simple inorganic substances like CO₂ and water using sunlight or chemical energy.
Example: Green plants (photosynthesis), some bacteria (chemosynthesis).
Process in plants: 6CO2 + 6H2O → C6H12O6 + 6O2 (in presence of sunlight and chlorophyll).
2. Heterotrophic Nutrition: Organisms cannot make their own food and depend directly or indirectly on autotrophs for food.
Types:
Holozoic: Ingestion of solid food (e.g., humans, Amoeba).
Saprophytic: Absorption of nutrients from dead organic matter (e.g., fungi, some bacteria).
Parasitic: Living on or inside another organism and deriving food from it (e.g., tapeworm, Cuscuta).
Symbiotic: Mutual benefit between two organisms (e.g., lichens – algae and fungi).
Q.30 Write any five differences between sexual and asexual reproduction.
Answer:
Examples:
Asexual: Binary fission (Amoeba), budding (Hydra), fragmentation (Spirogyra).
Sexual: Humans, flowering plants, frogs.
| S.No. | Asexual Reproduction | Sexual Reproduction |
|---|---|---|
| 1. | Involves only one parent | Involves two parents (male and female) |
| 2. | No formation or fusion of gametes | Involves formation and fusion of gametes |
| 3. | Offspring are genetically identical to the parent (clones) | Offspring show genetic variation |
| 4. | Faster process, large number of offspring produced quickly | Slower process, fewer offspring produced |
| 5. | No meiosis; only mitosis occurs | Involves meiosis and fertilization |
Examples:
Asexual: Binary fission (Amoeba), budding (Hydra), fragmentation (Spirogyra).
Sexual: Humans, flowering plants, frogs.