ICSE Class 10 Biology Sample Paper 2022 with Solutions

SECTION A

Question 1
Name the following by choosing the correct answers to the questions from the given options. (Do not copy the question, Write the correct answer only.) [10]

(i) A muscular wall is absent in: [1 Mark]
(a) Capillary
(b) Vein
(c) Venule
(d) Arteriole

Answer: (a) Capillary

Capillaries are extremely narrow blood vessels consisting of only a single layer of squamous endothelial cells without any muscular wall to facilitate easy diffusion.

Teacher's Note:
a) Remember that blood capillaries are microscopic vessels that connect arterioles and venules.
b) Students often confuse capillaries with venules; venules still possess very thin muscular and fibrous coats.

(ii) The outermost layer of meninges: [1 Mark]
(a) Piamater
(b) Arachnoid layer
(c) Grey matter
(d) Duramater

Answer: (d) Duramater

Duramater is the tough, fibrous outermost protective covering of the brain and spinal cord.

Teacher's Note:
a) The three meninges from outer to inner are Duramater, Arachnoid layer, and Piamater.
b) Pay close attention to spelling and sequence when answering questions about the nervous system layers.

(iii) Tear gland is also called: [1 Mark]
(a) Gastric gland
(b) Lacrimal gland
(c) Salivary gland
(d) Sebaceous gland

Answer: (b) Lacrimal gland

Lacrimal glands secrete tears which lubricate the front surface of the eye and wash away dust particles.

Teacher's Note:
a) Lacrimal glands are located at the upper sideward portion of the eye orbit.
b) Do not confuse sebaceous glands (oil glands of the skin) with lacrimal glands.

(iv) Which one of the following is not a simple reflex? [1 Mark]
(a) Coughing
(b) Blinking
(c) Eating
(d) Swallowing

Answer: (c) Eating

Eating is a voluntary action controlled by the conscious will of the cerebrum, whereas coughing, blinking, and swallowing are simple reflex actions.

Teacher's Note:
a) Simple reflexes are inborn, automatic, and rapid responses to stimuli not involving conscious thought.
b) Students must clearly distinguish between reflex actions and voluntary actions.

(v) Loop of Henle lies in: [1 Mark]
(a) Medulla
(b) Cortex
(c) Pelvis
(d) Ureter

Answer: (a) Medulla

The U-shaped loop of Henle is situated in the medullary region of the kidney.

Teacher's Note:
a) Malpighian capsule and convoluted tubules lie in the cortex, while the loop of Henle dips into the medulla.
b) Associate the loop of Henle correctly with the renal medulla to secure full marks.

(vi) The pigment that gives colour to urine: [1 Mark]
(a) Haemoglobin
(b) Chlorophyll
(c) Urochrome
(d) Melanin

Answer: (c) Urochrome

Urochrome is a yellow pigment derived from the breakdown of hemoglobin that gives normal urine its characteristic clean yellow color.

Teacher's Note:
a) Urochrome concentration determines the shade of yellow in urine.
b) Ensure exact terminology is used instead of writing descriptive phrases like yellow pigment.

(vii) The number of spinal nerves in humans: [1 Mark]
(a) 12 pairs
(b) 23 pairs
(c) 31 pairs
(d) 10 pairs

Answer: (c) 31 pairs

There are 31 pairs of spinal nerves arising from the spinal cord in humans.

Teacher's Note:
a) Do not confuse spinal nerves (31 pairs) with cranial nerves (12 pairs).
b) Always specify pairs when asked about the number of nerves.

(viii) The mineral element needed for the functioning of the Thyroid gland: [1 Mark]
(a) Sodium
(b) Potassium
(c) Magnesium
(d) Iodine

Answer: (d) Iodine

Iodine is an essential mineral required by the thyroid gland to synthesize the hormone thyroxine.

Teacher's Note:
a) Deficiency of iodine leads to undersecretion of thyroxine, causing goitre.
b) Mentioning the specific mineral element clearly is essential for scoring in this question type.

(ix) The part of the brain concerned with memory: [1 Mark]
(a) Cerebrum
(b) Cerebellum
(c) Pons
(d) Medulla Oblongata

Answer: (a) Cerebrum

The cerebrum is the seat of intelligence, memory, consciousness, and voluntary actions.

Teacher's Note:
a) Cerebellum coordinates muscular activity and maintains balance, whereas cerebrum handles memory.
b) Avoid confusing the functions of the cerebrum and cerebellum.

(x) The pigmented circular area seen in front of the eye: [1 Mark]
(a) Cornea
(b) Lens
(c) Iris
(d) Ciliary muscles

Answer: (c) Iris

The iris is the colored, pigmented circular muscular diaphragm in front of the eye lens that controls the size of the pupil.

Teacher's Note:
a) The color of the eye refers to the pigmentation of the iris.
b) Cornea is the transparent front part of the outer coat, not the pigmented area.

SECTION B

(Attempt any three questions from this Section.)

Question 2

(i) Explain the term ‘Tropic hormone’. Give one example of a Tropic hormone. [2 Marks]

Answer:
1. A tropic hormone is a hormone that stimulates other endocrine glands to secrete their specific hormones.
2. Example: Thyroid Stimulating Hormone (TSH) or Adrenocorticotropic Hormone (ACTH).

Teacher's Note:
a) Definition must clearly state the target as another endocrine gland.
b) Providing a correct example alongside the definition ensures full credit.

(ii) Give the location of Pericardial fluid. What is its function? [2 Marks]

Answer:
1. Location: It is present between the two walls of the pericardium surrounding the heart.
2. Function: It acts as a lubricant to reduce friction during heartbeats and protects the heart from mechanical shock and injury.

Teacher's Note:
a) Exact anatomical location must be specified.
b) Both friction reduction and mechanical protection are key points expected by examiners.

(iii) Given below is the diagram of a human blood smear. Label the parts numbered 1, 2 and 3. [3 Marks]

[Figure: Diagram of a human blood smear showing blood cells with pointer 1 to a lymphocyte/WBC, pointer 2 to an erythrocyte/RBC, and pointer 3 to platelets.]

Answer:
1. Red Blood Cell (Erythrocyte)
2. White Blood Cell (Leucocyte)
3. Platelets (Thrombocytes)

Teacher's Note:
a) Identification of blood cell types from diagrams is a standard board question.
b) Writing either common names or scientific terms is accepted, but providing both is best practice.

(iv) Give the biological terms for the three ear ossicles. [3 Marks]

Answer:
1. Hammer - Malleus
2. Anvil - Incus
3. Stirrup - Stapes

Teacher's Note:
a) Students should learn both common English names and Latin biological terms for ear ossicles.
b) Spelling of anatomical terms like Malleus, Incus, and Stapes must be accurate.

Question 3

(i) Mention two structural differences between an artery and a vein. [2 Marks]

Answer:

Teacher's Note:
a) Any two correct structural differences (such as wall thickness, lumen size, or presence of valves) are awarded full marks.
b) Tabular presentation makes answers clear and easy to evaluate.

(ii) Where is Bicuspid valve located? What is its function? [2 Marks]

Answer:
1. Location: It is located between the left auricle and the left ventricle.
2. Function: It prevents the backflow of blood from the left ventricle into the left auricle during ventricular contraction.

Teacher's Note:
a) Location must specify the exact chambers connected by the valve.
b) Mentioning the prevention of backflow is essential for the functional description.

(iii) Draw a neat diagram of a Malpighian capsule and label any two parts. [3 Marks]

[Figure: Diagram of a Malpighian capsule showing Bowman's capsule, glomerulus, afferent arteriole, and efferent arteriole.]

Answer:
Diagram showing Bowman's capsule enclosing the glomerulus, fed by an afferent arteriole and drained by an efferent arteriole.
Labels: 1. Bowman's capsule, 2. Glomerulus (or Afferent arteriole).

Teacher's Note:
a) Diagrams should be neat, correctly proportioned, and clearly labeled with pencil.
b) Labeling any two valid parts secures full marks.

(iv) Define the term ‘Excretion’. Which are the two main organic wastes present in urine? [3 Marks]

Answer:
1. Definition: Excretion is the process of removal of chemical nitrogenous metabolic wastes from the body.
2. Organic wastes: Urea and uric acid (or creatinine).

Teacher's Note:
a) The definition must highlight the removal of metabolic or nitrogenous wastes.
b) Students must list specific organic constituents as mentioned in the curriculum.

Question 4

(i) Name the substance that initiates blood clotting. What is the mineral element essential to form a blood clot? [2 Marks]

Answer:
1. Substance: Thrombokinase (or thromboplastin) released by damaged platelets.
2. Mineral element: Calcium (Ca²⁺ ions).

Teacher's Note:
a) Thrombokinase converts prothrombin to thrombin during blood coagulation.
b) Calcium ions are an indispensable cofactor for this enzymatic conversion.

(ii) Give the exact location of Adrenal glands. [2 Marks]

Answer:
Adrenal glands are located like caps immediately above each kidney in the abdominal cavity.

Teacher's Note:
a) Mentioning the anatomical relation to the kidneys is vital.
b) Describing them as suprarenal glands adds precision to the answer.

(iii) Mention three functions of Adrenaline. [3 Marks]

Answer:
1. It increases the heart rate and blood pressure during emergency situations.
2. It increases blood supply to skeletal muscles while decreasing it to the skin and visceral organs.
3. It stimulates the liver to release more glucose into the blood to provide instant energy.

Teacher's Note:
a) Adrenaline is known as the emergency hormone preparing the body for fight or flight.
b) List three distinct physiological effects for full marks.

(iv) What is the contraction phase of auricles called? Name the two valves that open during this phase. [3 Marks]

Answer:
1. Contraction phase: Atrial systole.
2. Valves that open: Tricuspid valve and bicuspid (mitral) valve.

Teacher's Note:
a) Atrial systole forces blood from auricles into the ventricles.
b) The AV valves open while semilunar valves remain closed during this phase.

Question 5

(i) How are cytons and axons arranged in the spinal cord? [2 Marks]

Answer:
In the spinal cord, the grey matter containing cytons lies on the inner side (in the shape of an H or butterfly), while the white matter containing myelinated axons lies on the outer side.

Teacher's Note:
a) Note that this arrangement is the exact reverse of the cerebrum in the brain.
b) Clearly state the positions of both grey and white matter.

(ii) We cannot distinguish colours in dim light. Explain giving suitable reasons. [2 Marks]

Answer:
1. Colour vision is a function of cone cells in the retina, which are sensitive to bright light and require high light intensity to function.
2. In dim light, only rod cells (which are sensitive to dim light but incapable of distinguishing colours) are functional.

Teacher's Note:
a) Distinguish clearly between the functions of rods (dim light) and cones (bright light and colour).
b) Both cell types must be referenced to explain the phenomenon completely.

(iii) Given below is a diagram depicting a defect of the human eye. Answer the questions that follow: [3 Marks]

[Figure: Diagram of an eyeball showing parallel rays focusing in front of the retina, depicting myopia.]

(a) Give the scientific term for the defect.
(b) Mention one possible reason for the defect.
(c) What type of lens can be used to correct the defect?

Answer:
(a) Myopia (short-sightedness).
(b) Eyeball is lengthened from front to back, or the eye lens is too curved.
(c) Concave (diverging) lens.

Teacher's Note:
a) Sub-parts must be answered precisely in order.
b) Mentioning either elongation of the eyeball or excessive curvature of the lens is sufficient for reason.

(iv) What are hormones? Name any two hormones secreted by the Pituitary gland? [3 Marks]

Answer:
1. Hormones are organic secretions produced by endocrine glands, poured directly into the blood, and acting on specific target organs or cells in the body.
2. Two hormones secreted by the pituitary gland: Growth Hormone (GH) and Thyroid Stimulating Hormone (TSH).

Teacher's Note:
a) Definition must include production by endocrine glands and transport via blood.
b) Any two correct pituitary hormones (such as ACTH, ADH, Oxytocin) are accepted.

Question 6

(i) From where the following nerves arise. [2 Marks]

(a) Optic nerve
(b) Auditory nerve

Answer:
(a) Optic nerve: Arises from the retina of the eye / Diencephalon.
(b) Auditory nerve: Arises from the sensory cells of the cochlea (inner ear).

Teacher's Note:
a) Origin points of cranial nerves must be stated accurately.
b) Mentioning the sensory receptors or brain regions associated with each nerve ensures full marks.

(ii) Give the full form of the following abbreviations: [2 Marks]

(a) T S H
(b) A D H

Answer:
(a) TSH - Thyroid Stimulating Hormone
(b) ADH - Antidiuretic Hormone

Teacher's Note:
a) Spelling of hormonal abbreviations must be exact.
b) Capitalization and spacing should follow standard biological nomenclature.

(iii) What are the three main parts of the membranous labyrinth? [3 Marks]

Answer:
1. The semicircular ducts.
2. Two sac-like structures (the saccule and the utricle in the vestibule).
3. The cochlear duct.

Teacher's Note:
a) The membranous labyrinth is enclosed within the bony labyrinth of the inner ear.
b) Listing all three component structures is required to secure full marks.

(iv) Complete the following table by filling in the blanks (a) to (c): [3 Marks]

Answer:
(a) Insulin
(b) Thyroxine
(c) Exophthalmic goitre

Teacher's Note:
a) Oversecretion of insulin leads to hypoglycemia (low blood sugar), while oversecretion of thyroxine causes exophthalmic goitre.
b) Students should pay attention to table-based questions and ensure corresponding row-column data matches precisely.