Explanation: Asbestos is a group of naturally occurring fibrous silicate minerals once widely used in construction and insulation. When inhaled, asbestos fibers accumulate in the lungs and pleura, leading to inflammation and scarring over years. This chronic exposure can cause asbestosis (lung fibrosis) and mesothelioma — a deadly cancer of the membrane lining the lungs (pleura) or abdomen (peritoneum).

Explanation: Kala-azar, also known as visceral leishmaniasis, is caused by the protozoan parasite Leishmania donovani. It is transmitted through the bite of the female Phlebotomus sandfly. The disease primarily affects the liver, spleen, and bone marrow, leading to symptoms such as fever, anemia, weight loss, and darkening of the skin. The term “Kala-azar” literally means “black fever.”

Explanation: Dialysis is a medical procedure prescribed for patients suffering from kidney failure or severe kidney disease. When the kidneys lose their ability to filter waste products, excess salts, and water from the blood, dialysis performs this function artificially. It helps maintain the body’s chemical balance and remove toxins such as urea and creatinine. There are two main types of dialysis: hemodialysis (using a dialysis machine and artificial kidney) and peritoneal dialysis (using the lining of the abdomen as a filter).

Explanation: Tuberculosis (TB) is not a viral disease; it is caused by a bacterium called Mycobacterium tuberculosis. In contrast, Polio, Swine flu, and Hepatitis are viral diseases caused by different types of viruses.

Explanation: The nephron is the basic structural and functional unit of the kidney. Each human kidney contains about 1 to 1.5 million nephrons. A nephron consists of two main parts — the renal corpuscle (Bowman's capsule and glomerulus) and the renal tubule. It performs three main functions: filtration of blood, reabsorption of essential substances, and secretion