Test: Excretion in Humans - Year 11 MCQ

The glomerulus filters blood under pressure, allowing small molecules like glucose, water, and urea to move into the Bowman's capsule and form filtrate.

The proximal convoluted tubule is where glucose is actively reabsorbed into the bloodstream. This segment contains transporters and mitochondria for active transport.

Excess amino acids are deaminated in the liver, converting the amino group into ammonia, which is then converted into urea for safer excretion.

Carbon dioxide is primarily excreted through the lungs, where it is removed from the blood and exhaled.

High levels of urea can lead to cell death and deposits in blood vessels, as it becomes toxic if not excreted effectively.

The reabsorption of salts in the Loop of Henle triggers the movement of water by osmosis, leading to increased water reabsorption.

In healthy individuals, glucose is reabsorbed completely in the proximal convoluted tubule, so it is not found in the urine.

The collecting duct is responsible for the final adjustment of urine concentration, influenced by the body's hydration needs.

High blood carbon dioxide levels trigger an increase in respiration rate to expel more carbon dioxide and restore normal pH levels.

The main purpose of ultrafiltration is to filter small molecules from the blood into the Bowman's capsule, forming the filtrate that will be processed further in the nephron.