Karan was standing on a high stool and cleaning the ceiling fan.
He suddenly loses balance and sustains a head injury. An examination reveals that his pupils have lost the capacity to constrict in bright light. Which structure has been damaged?
The loss of the ability to constrict pupils in bright light suggests a disruption in the autonomic regulation of the eye. The autonomic nervous system, which controls pupil constriction and dilation, is governed by structures in the brainstem, particularly the midbrain and the medulla oblongata.
- (A) Suspensory ligaments: These are ligaments that hold the eye lens in place. They don't have a direct role in controlling pupil constriction, so this is not the correct answer.
- (B) Medulla oblongata: The medulla oblongata, part of the brainstem, is responsible for regulating autonomic functions like heart rate, breathing, and pupil constriction. Damage to the medulla could impair the pupillary reflex.
- (C) Eye lens: The eye lens is responsible for focusing light onto the retina but does not control pupil constriction. This is not the correct answer.
- (D) Eye lid: The eyelid protects the eye and plays a role in blinking but does not regulate pupil constriction. This is not the correct answer.
The inability to constrict the pupils in bright light is indicative of damage to the medulla oblongata, which controls the autonomic functions of the pupils. Therefore, the correct answer is (B).
Final Answer: (B) Medulla oblongata.
Rajat Singh was working as a supervisor in a stone quarry where rock, sand and gravel are extracted by techniques like digging, drilling, and blasting. As the years rolled by, Rajat started facing a loss in hearing. The high decibel sounds had damaged a part of his internal ear, though the tympanic membrane was intact.
(a) Give the collective term for the structure located in the internal ear.
(b) Name the sensory organ in the Cochlea which was damaged for Rajat Singh.
(c) What kind of pollution do the workers face in the stone quarry?
Tara's grandmother is 70 years old and has a passion for embroidery. She faces difficulty in threading the needle as the eye of the needle appears blurred. The ophthalmologist diagnosed it as an age-related disorder.
(a) Name the eye disorder she is suffering from.
(b) How can the above defect be corrected?
(c) Where is the image formed in the above disorder? 
Bharat woke up late in the morning and missed the school bus.
This situation stimulated the nerves of the sympathetic system which resulted in: 
Copy the diagram given below.
(a) Name the structure.
(b) Label Gray matter and White matter.

"Vanishing Greenery; A Growing Urban Crisis" In most of our cities, rapid urbanisation has led to a significant decrease in greenery over the past two decades. As the population increased, the demand for housing, roads and commercial buildings grew, leading to clearing of parks, gardens, and natural resources. This has contributed to several problems.
(a) Mention one significant problem caused by the reduction in urban greenery.
(b) How do green plants contribute to improving the air quality?
(c) What role can you, as a citizen, play in protecting urban greenery?