NEET Biology: Urine formation Practice Questions
15 free multiple-choice questions on Urine formation (Excretory Products and their elimination) for NEET Biology, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. What is the primary function of the collecting ducts in urine formation?
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Correct answer: D — Final concentration of urine
The collecting ducts receive the filtrate and are crucial for the final adjustment and concentration of the urine, regulated by ADH.
Q2. Which of the following substances is the primary component that is filtered from the blood in the glomerulus during the initial stage of urine formation?
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Correct answer: D — Water
The initial stage of urine formation involves glomerular filtration, where blood plasma is filtered. Water and small solutes (like glucose and salts) are filtered out into the Bowman's capsule, forming the filtrate.
Q3. Which segment of the nephron is mainly responsible for the reabsorption of water and solutes?
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Correct answer: D — Proximal convoluted tubule (PCT)
The Proximal Convoluted Tubule (PCT) is the site where the majority (about 65-70%) of water and solutes are actively reabsorbed from the filtrate back into the blood.
Q4. Which of the following is the main excretory product of nitrogenous waste in humans?
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Correct answer: A — Urea
Urea is the principal end product formed when amino acids are broken down in the liver and excreted by the kidneys.
Q5. The primary site where most of the reabsorption of water occurs in the renal tubule is the area of the nephron that is inversely proportional to the length of the renal medulla.
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Correct answer: D — Loop of Henle
The Loop of Henle, with its descending and ascending limbs, is crucial for establishing the osmotic gradient necessary for water reabsorption and concentration of urine.
Q6. The primary site where blood is filtered to form urine is the:
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Correct answer: B — Nephron
While the nephron is the functional unit, the filtration process occurs across the capillaries within the renal cortex, which feeds the nephrons.
Q7. The increase in the osmotic concentration of the renal medulla is primarily achieved by the presence of which structure?
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Correct answer: A — Loop of Henle
The Loop of Henle, particularly the ascending limb, establishes the osmotic gradient necessary for concentrating urine.
Q8. Which blood component is primarily filtered from the blood into the renal tubule to initiate urine formation?
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Correct answer: B — Plasma
Blood plasma, which contains dissolved waste products and water, is the fluid that is filtered by the glomerulus.
Q9. The selective reabsorption of useful substances from the filtrate occurs mainly in which part of the nephron?
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Correct answer: A — Loop of Henle
The majority of reabsorption and secretion occurs along the convoluted tubules (proximal and distal convoluted tubules) and the Loop of Henle.
Q10. Urine formation is a three-step process. What is the final step involving the removal of waste products from the blood into the filtrate?
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Correct answer: B — Secretion
Secretion is the active transport process where substances are moved from the blood into the renal tubule to be excreted as urine.
Q11. Which structure in the nephron is responsible for the initial non-selective filtration of blood plasma?
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Correct answer: C — Glomerulus
The Glomerulus is a network of capillaries where blood enters the nephron. Filtration occurs here, where water and small solutes are filtered out of the blood into Bowman's capsule.
Q12. The majority of water reabsorption from the renal tubules occurs in which part of the nephron?
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Correct answer: D — Proximal convoluted tubule
The Proximal convoluted tubule (PCT) is responsible for the bulk reabsorption of water and solutes (about 65-70%) from the filtrate.
Q13. Which process involves the selective reabsorption of useful substances from the filtrate back into the blood?
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Correct answer: A — Reabsorption
Reabsorption is the process where water and solutes are moved from the filtrate back into the renal tubule and subsequently into the blood.
Q14. Which substance is selectively reabsorbed by the renal tubules and returned to the blood?
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Correct answer: B — Glucose
Glucose and amino acids are essential nutrients that must be reabsorbed back into the blood from the filtrate for the body to survive.
Q15. Which structure in the nephron is primarily responsible for establishing the osmotic gradient necessary for concentrating urine by creating a countercurrent flow of filtrate?
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Correct answer: D — Loop of Henle
The Loop of Henle is crucial for urine concentration. Its structure, involving a descending limb and an ascending limb, facilitates the creation of a concentration gradient in the renal medulla, which is essential for water reabsorption and thus urine concentration.
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