Zoology MCQs for NEET — Practice Questions with Answers

The kidneys are reddish-brown in color. This color is due to the rich supply of blood they receive, which is necessary for their function of filtering waste products from the bloodstream.

Glucose is reabsorbed from the glomerular filtrate through active transport. This is an energy-dependent process where glucose molecules are transported against their concentration gradient using carrier proteins.

Birds and reptiles excrete uric acid as their primary nitrogenous waste product. Uric acid is less toxic and conserves water, which is beneficial for these organisms living in arid environments.

The left kidney is positioned slightly higher than the right kidney in the human body. This is because the right kidney lies beneath the large liver, which takes up significant space on the right side of the abdominal cavity.

Both vasopressin (also known as antidiuretic hormone, or ADH) and aldosterone play crucial roles in regulating kidney function. Vasopressin increases water reabsorption in the kidneys, while aldosterone promotes sodium reabsorption and potassium excretion, both contributing to fluid balance and blood pressure regulation.

Urea is transported through the blood plasma. It is produced in the liver as a waste product of protein metabolism and is carried by the blood plasma to the kidneys, where it is filtered out and excreted in urine.

Angiotensinogen is a protein produced and secreted by liver cells. It is a precursor to angiotensin, which plays a crucial role in blood pressure regulation and fluid balance in the body. The liver synthesizes angiotensinogen, which is then released into the bloodstream.

The principal nitrogenous excretory compound in humans is urea. Urea is synthesized in the liver through the urea cycle and is then transported to the kidneys for elimination. The liver converts ammonia, which is toxic, into urea, which is less toxic and can be excreted efficiently by the kidneys.

Uricotelic organisms excrete nitrogenous waste primarily in the form of uric acid. This mode of excretion is found in reptiles and birds. Uric acid is less toxic and requires less water to excrete, which is advantageous for these animals that often live in arid environments.