JCW'S G9 U13 QUIZ 2023-2025 CIE

What is the basic structural unit of a Kidney?

• Nephros

• Nephron

• Nephra

• Nephrit

Answer explanation

The filtering unit of a kidney. Consisting of several parts, with the 2 significant ones being the Glomerulus and the Tubules.

How many nephrons are there in one kidney?

• 10,000,000

• 500,000

• 1,000,000

• 100,000

Answer explanation

There's around 1million nephrons per kidney.

Which is not an example of excretion?

• Sweating

• Urinating

• Exhaling

• Egesting

Answer explanation

Egesting is not the same as Excreting. Egesting is the removal of undigested food, or faeces.

What is Urine made of in a healthy person?

• Water, Urea, Uric Acid, Salts/Minerals

• Urea, Salt/Minerals, Uric Acid, Mucus

• Mineral Ions, Glucose, Water, Urea, Oxygen

• Red Blood Cells, Water, Potassium, Mineral Ions, Urea

Answer explanation

Water, Urea, Uric Acid, Salts are the constituents of Urine.

The bed of capillaries where filtration takes place in the Nephron is called a _________.

Answer explanation

The bed of capillaries within the nephron is called a Glomerulus. This is where the filtration of blood takes place, where substances pass into the tubule system of the nephron.

Which of these is true about ultrafiltration

• All of the salts are re-absorbed back into the blood when passing through the tubule system.

• In a healthy person, all of the glucose is reabsorbed back into the blood when passing through the tubule system.

• A diabetic person is more capable of reabsorbing their glucose.

• Drinking larger amounts of water will increase your blood pressure and ultrafiltration rate.

Answer explanation

Glucose is a useful carbohydrate, monosaccharide. The body usually selectively reabsorbs all glucose in order to use it in respiration. If it is not used immediately, then it is linked to form Glycogen or converted into fatty acids in the Liver. These molecules are then used as a longer-term energy store.

Which of the following statements is false?

• The liver is the main site in the body of assimilating amino acids, turning them into proteins.

• The liver is capable of deaminating excess amino acids, turning them into DNA.

• The liver is responsible for the deamination of excess amino acids, turning them into ammonia and then Urea.

• The liver produces bile salts which are later secreted in order to emulsify fats to aid in digestion.

Answer explanation

Deamination is the removal of an amino group (NH2) from an amino acid. Deaminases are enzymes responsible for doing this. This forms ammonia which is a toxic alkaline.

This organ is responsible for transporting urine from the Kidneys to the Bladder.

• Ureter

• Urethra

• Uitar

• Urefra

Why is urea removed in excretion?

• There wouldn't be a need for the kidneys if we kept urea.

• Build-ups of Urea are helpful but not useful to the body's protein synthesis.

• Higher concentrations of Urea in the blood will stimulate the body to create too many white blood cells.

• Build-ups of urea are toxic to the body's metabolism and cell function

Which of the following organs is not capable of removing water?

• Lungs

• Liver

• Kidneys

• Urethra

Answer explanation

Humans excrete water in exhalation in the form of water vapour. Kidneys are primarily involved in the removal of excess water. The urethra is the organ with the passageway responsible for removing water from the body in the Urine. The Liver does not play a role in the removal of excreting water.