Excretory Products and Their Elimination MCQs for NEET — Zoology Questions with Answers

Uric acid in humans is formed from the breakdown of purines, which are nitrogen-containing compounds found in DNA and RNA. The liver converts purines into uric acid, which is then excreted by the kidneys.

Green glands, also known as antennal glands, are excretory organs found in crustaceans such as prawns. They play a role in osmoregulation and waste removal. These glands are located near the base of the antennae.

In earthworms, the excretory structures are nephridia. Nephridia are tubular structures that help in the excretion of waste materials from the body. They function similarly to kidneys in higher organisms and are distributed throughout the segments of the earthworm's body.

The 'Columns of Bertini' are extensions of the renal cortex into the medulla of the kidney. These columns are made up of cortical tissue and help support the functional units of the kidney, the nephrons, by providing a pathway for blood vessels and nerves.

Each human kidney contains approximately 1 million nephrons. Nephrons are the functional units responsible for filtering blood and forming urine. This large number of nephrons ensures efficient filtration and waste removal from the body.

The adrenal cortex regulates urinary excretion of $Na^+$ through the secretion of aldosterone. Aldosterone increases the reabsorption of sodium ions in the kidneys, which helps in maintaining electrolyte balance and blood pressure.

The yellow color of urine in vertebrates is primarily due to the presence of urochrome. Urochrome is a pigment that results from the breakdown of hemoglobin from dead red blood cells. This pigment is what gives urine its characteristic yellow color.

The glomerular filtration rate (GFR) in a normal adult is approximately 125 ml/min. This rate indicates the amount of blood that is filtered by the glomeruli of the kidneys per minute. It is a crucial indicator of kidney function.