Solved 2022 Semester 2 Question Paper ICSE Class 10 Biology

Iron

Reason — Iron forms the prosthetic group i.e haemin which combines with globin protein to form haemoglobin.

12 pairs

Reason — The cranial nerves are a set of 12 paired nerves in the back of the brain.

Hypersecretion of Growth hormone

Reason — Acromegaly and Gigantism are disorder in adults in which the pituitary gland produces too much of Growth hormone.

Heart

Reason — Pericardium is a double walled membranous bag, enclosing the human heart.

Pupil

Reason — Pupil is a small opening in the center of the iris, through which the light enters into the eye.

Pulmonary vein

Reason — The pulmonary veins carry oxygenated blood from the lungs to the left atrium.

Cochlea

Reason — The Organ of corti is present in the cochlea. It is a structure present on the basilar membrane. It contains hair cells that act as auditory receptors.

Urinary bladder

Reason — The urine formed in kidneys is taken by ureters to urinary bladder where it is temporarily stored.

Pancreas

Reason — Islets of Langerhans are endocrine cells present in Pancreas. They have three type of cells alpha, beta and delta cells.

Urea

Reason — Urea forms the main nitrogenous waste in human body.

Simple goitre is usually seen in people living in the hilly regions because:

1. Iodine is deficient in soil of hilly regions and hence in the food grown there.
2. Iodine is also deficient in drinking water available in the hilly regions which is obtained from rivers and streams fed by melting snow.

The two types of blood circulation in humans are:

1. Pulmonary circulation
2. Systemic circulation

The three major steps involved in the production of urine are:

1. Ultrafiltration
2. Reabsorption
3. Secretion

Diagram of Neuron with Cyton and Axon labelled is shown below:

The overgrowth of adrenal cortex in a mature woman leads to the development of certain male characteristics in her such as a beard, a moustache and deep male voice. This condition is known as Adrenal Virilism.
It caused due to the oversecretion of sex corticoids (adrenal androgens).

Retina is the light sensitive layer of the eyeball. Image is formed on retina.

(a) Hyperopia.

(b) Lens is too flat.

(c) Convex lens.

Malleus, Incus and Stapes.

Thyroid gland secretes thyroxine.

One function of thyroxine — It regulates the basal metabolism, i.e., the rate of cellular oxidation resulting in heat production at rest.

Adrenocorticotropic Hormone.
It is secreted by pituitary gland.

Synapse is the point of contact between the terminal branches of the axon of a neuron with the dendrites of another neuron separated by a fine gap.
In the Cerebrum, Cytons are present in the outer portion (cortex) constituting the gray matter and Axons are present in the inner portion constituting the white matter.

1. Dura mater (outer layer)
2. Arachnoid (middle layer)
3. Pia mater (inner layer).

(a) Auditory nerve

(b) Optic nerve

Lack of nucleus and mitochondria helps erythrocytes in the following ways:

1. Loss of nucleus makes the red cells biconcave, thus increasing their surface area to absorb more oxygen.
2. Loss of mitochondria means that they cannot use the absorbed oxygen themselves.

(a) Parts numbered 2 and 3 are:

• 2 → Cerebellum
• 3 → Medulla oblongata

(b) The part labelled as 1 is Cerebrum. It is the seat of intelligence, consciousness and will-power. It controls all voluntary actions.

Reflex action is an automatic/quick/immediate, involuntary action in the body brought about by a stimulus. The two types of reflexes are natural reflexes and conditioned reflexes.

Pulmonary semilunar valves are located at the opening of the right ventricle into the pulmonary artery. It closes during the atrial systole phase of the cardiac cycle.

(a) Diabetes mellitus - Insulin

(b) Diabetes insipidus - Vasopressin

Diagram showing longitudinal section of a human kidney with Renal Cortex and Renal Medulla labelled is shown below:

(a) Lymphocytes produce antibodies which kill or neutralise the germs or the poisons from them.

(b) Thrombocytes help to form blood clots in order to slow or stop bleeding and help wounds to heal.

(c) Neutrophils engulf bacterial and fungal pathogens through a process known as phagocytosis.