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

Lungs primarily expel carbon dioxide (COâ‚‚) and water vapor. When we exhale, our breath contains these two components as waste products of cellular respiration. This process helps in maintaining the body's acid-base balance.

The glomeruli are located in the cortex of the kidney. The cortex is the outer part of the kidney where the glomeruli filter blood to form urine. This filtered blood then moves into the renal tubules for further processing.

A kidney stone is typically a crystallized salt, such as calcium oxalate, formed in the renal pelvis. These stones can cause severe pain and block the flow of urine, leading to various complications if not treated.

The Proximal Convoluted Tubule (PCT) is the region of the nephron where maximum reabsorption of useful substances like glucose, amino acids, and ions occurs. This is due to the presence of a large surface area and numerous microvilli that facilitate reabsorption.

The excretory organs of a cockroach are the Malpighian tubules. These tubules help in the removal of nitrogenous wastes from the hemolymph and play a crucial role in osmoregulation.

Juxta glomerular cells of the renal cortex synthesize the hormone renin. Renin plays a key role in the regulation of blood pressure and electrolyte balance by activating the renin-angiotensin-aldosterone system (RAAS).

The renal vein carries the least amount of urea because it is responsible for transporting blood that has been filtered by the kidneys. During filtration, the kidneys remove waste products like urea from the blood, resulting in lower urea levels in the blood that exits the kidneys through the renal vein.

The assertion (A) that ammonia should be eliminated from the body as rapidly as it is formed is true because ammonia is highly toxic to cells. However, the reason (R) is false because ammonia is actually very soluble in water. Therefore, the correct option is 'If A is true then R is false.'

Both assertion (A) and reason (R) are true and the reason correctly explains the assertion. In the descending limb of the loop of Henle, water is reabsorbed, making the urine hypertonic. In the ascending limb, sodium ions (Na+) are actively transported out, and this limb is impermeable to water, making the urine hypotonic. Therefore, the correct option is 'If both the ‘A’ and ‘R’ are true and ‘R’ is a correct explanation of ‘A’.'

Both are true