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Free Homeostasis MCQs with Answers

698 Homeostasis MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.

Homeostasis maintains a stable internal environment through the kidney and urinary system, thermoregulation and excretion. The kidney topics include filtration, selective reabsorption, urine formation and water balance, while thermoregulation involves sweating, vasodilation, vasoconstriction and hormonal control; excretion is different from egestion, which removes undigested food.

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Kidney and Urinary SystemThermoregulationExcretion
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698 questions · page 30 of 35

581. If A is coded as -, B is coded as +, C is coded as × , and D is coded as /, then evaluate 8 A 1 B 11 C 12 D 4 C 5.

  • A. 173
  • B. 174
  • C. 182
  • D. 172

Explanation: Substituting the operators gives the expression 8 - 1 + 11 × 12 / 4 × 5.

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Correct answer: 172

582. Statement: There has been less than forty percent voter turnout in the recent assembly elections.Courses of Action:I. The election commission should cancel the entire election process as the votes cast are not adequate to represent people.II. The election commission should take away the voting rights of those who did not exercise their rights.

  • A. Only I follows
  • B. Only II follows
  • C. Either I or II follows
  • D. Neither I nor II follows
  • E. Both I and II follow

Explanation: The correct answer is Option D: Neither I nor II follows. Canceling the election due to low turnout would incur unnecessary expenses and…

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Correct answer: Neither I nor II follows

583. The urine test report of a person shows the presence of free haemoglobin in urine, indicating that the red blood cells have been lysed.The part of nephron that MOST LIKELY shows malfunctioning in the given situation is

  • A. Glomerulus
  • B. Loop of Henle
  • C. Collecting duct
  • D. Proximal convoluted tubule

Explanation: The presence of free hemoglobin in urine suggests that hemoglobin is not being properly reabsorbed or processed by the nephron.

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Correct answer: Proximal convoluted tubule

584. In the human kidney, the part of nephron where receptors for antidiuretic hormone (ADH) are found is

  • A. Glomerulus
  • B. Ascending loop of Henle
  • C. Descending loop of Henle
  • D. Collecting duct

Explanation: The correct answer is the collecting duct. The collecting duct is where the receptors for antidiuretic hormone (ADH) are located.

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Correct answer: Collecting duct

585. Bony fish have some physiological adaptations which enable them to live in sea water.The adaptation in glomerular filtration rate and the function of the salt secretory cells in the gills of these fish is

  • A. A
  • B. B
  • C. C
  • D. D

Explanation: Bony fish have adapted to seawater by decreasing their glomerular filtration rate to conserve water and using specialized cells in their…

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Correct answer: B

586. As compared to the nephrons of fresh water vertebrates, the nephrons of desert rodents have

  • A. Longer loop of Henle
  • B. Shorter collecting duct
  • C. Less convoluted distal tubule
  • D. More convoluted proximal tubule

Explanation: The correct answer is a longer loop of Henle. The loop of Henle, found in the nephron of the kidney, plays a crucial role in the…

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Correct answer: Longer loop of Henle

587. Vasa recta is the cluster of blood capillaries present in the nephron of human beings. It isderived from X and surrounds Y, where X are arterioles and Y are tube-like structures.Which of the following CORRECTLY identifies X and Y?

  • A. A
  • B. B
  • C. C
  • D. D

Explanation: The vasa recta is a series of blood capillaries in the nephron that play a crucial role in the counter-current exchange system, essential…

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Correct answer: C

588. A person is suffering from hyper-secretion of aldosterone.The laboratory report of his urine composition will show the absence or very low level of

  • A. Glucose
  • B. Creatinine
  • C. Sodium ions
  • D. Phosphate ions

Explanation: The correct answer is sodium ions. Aldosterone is a hormone that promotes the reabsorption of sodium ions from the renal tubules back into…

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Correct answer: Sodium ions

589. The option that CORRECTLY identifies the process of osmoregulation (water intake andexcretion of salts) in marine bony fishes is

  • A. A
  • B. B
  • C. C
  • D. D

Explanation: Marine animals are constantly battling dehydration due to the hypertonic environment of seawater.

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Correct answer: B

590. The given diagram shows a nephron of human kidney, highly hypertonic filtrates found in region

  • A. I and II
  • B. I and III
  • C. II and IV
  • D. III and IV

Explanation: The correct answer is III and IV. Region III corresponds to the loop of Henle, particularly the bottom of the descending limb, where the…

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Correct answer: III and IV

591. Antidiuretic hormone (ADH) affects the functioning of human nephron If ADH is secreted in low quantity, then it affects the

  • A. reabsorption of water in collecting duct.
  • B. removal of hydrogen ions from peritubular capillaries.
  • C. removal of water from ascending limb of loop of Henle
  • D. reabsorption of sodium ions in the proximal convoluted tubule

Explanation: ADH affects reabsorption of water in collecting duct. Normally it increases the water reabsorption in collecting duct concentrating the…

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Correct answer: reabsorption of water in collecting duct.

592. The given diagram 1 represents a healthy numan nephron.In contrast to filtrate at point X, the filtrate at point Y has

  • A. Lesser salt concentration
  • B. Greater red blood cell count
  • C. Lesser number of plasma proteins
  • D. Greater number of glucose molecules

Explanation: The correct answer is Option A:lesser salt concentration As the filtrate passes through the nephron, particularly from the glomerulus to…

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Correct answer: Lesser salt concentration

593. One of the ways through which freshwater fish compensate the loss of salts from their bodies is that they

  • A. Drink large amounts of water
  • B. Produce small volumes of concentrated urine
  • C. Uptake salts by gills and skin via active transport
  • D. Retain adequate concentrations of urea in their bodies

Explanation: The correct answer is that freshwater fish uptake salts by gills and skin via active transport (Option C).

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Correct answer: Uptake salts by gills and skin via active transport

594. In people with a kidney disease, the over-use of painkillers causes blood cells to leak in urine.This is because the pain killers MAINLY

  • A. Cause the hypersecretion of anti-diuretic hormone
  • B. Reduce the efficiency of glomerulus to filter the blood
  • C. Increase the reabsorption of water through the descending loop of Henle
  • D. Decrease the reabsorption of sodium through ascending loop of Henle

Explanation: The correct answer is that painkillers, particularly NSAIDs, reduce the efficiency of the glomerulus to filter the blood.

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Correct answer: Reduce the efficiency of glomerulus to filter the blood

595. In the human kidney,the labelled part where all the collecting ducts of nephrons open is

  • A. A
  • B. B
  • C. C
  • D. D

Explanation: Structure labelled C is renal pelvis. Collecting ducts of the nephrons open into the renal pelvis, where urine is collected before it…

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Correct answer: C

596. Homeostasis of blood osmotic pressure is maintained by which organ(s)?

  • A. Lungs
  • B. Kidneys
  • C. Heart
  • D. Liver

Explanation: The kidneys play a central role in maintaining blood osmotic pressure through the regulation of water and electrolyte balance.

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Correct answer: Kidneys

597. Antidiuretic hormone promotes the retention of water by stimulating the

  • A. Active transport of water
  • B. Active transport of chloride
  • C. Active transport of sodium
  • D. Permeability of collecting duct to water

Explanation: When ADH makes it to your kidneys, it signals them to conserve water and produce more concentrated urine.

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Correct answer: Permeability of collecting duct to water

598. Antidiuretic hormone promotes the retention of water by action on

  • A. X: Efferent arterioles, Y: Proximal convoluted tubule
  • B. X: Afferent arterioles, Y:Proximal convoluted tubule
  • C. X: Efferent arterioles, Y: Loop of Henle
  • D. X: Distal tubules Y: Loop of Henle

Explanation: ADH released from the posterior pituitary lobe acts to actively transport water from filtrate in Distal tubules and collecting tubules…

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Correct answer: X: Distal tubules Y: Loop of Henle

599. The following diagram shows the nephron. Identify the processes that occur at X and Y.

  • A. Selective Reabsorption, Ultrafiltration
  • B. Diffusion, Tubular secretion
  • C. Ultrafiltration, Selective Reabsorption
  • D. Active Transport, Selective Reabsorption

Explanation: Bowman's capsule surrounds the glomerular capillary loops and participates in the filtration of blood from the glomerular capillaries.

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Correct answer: Ultrafiltration, Selective Reabsorption

600. _ are animals that do not adjust their internal osmolality and are isotonic with their environment.

  • A. Osmoconformers
  • B. Osmoregulators
  • C. Thermoregulators
  • D. Thermoconformers

Explanation: Osmoconformers are animals that do not actively regulate their internal osmolarity, but instead match it to that of their environment.

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Correct answer: Osmoconformers
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