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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Read the Homeostasis notesFree MDCAT chapter notes with key terms698 questions · page 13 of 35
- A. An isotonic environment
- B. A hypotonic environment
- C. A hypertonic environment
- D. Any environment
Explanation: Hypotonic refers to a solution with a lower concentration of solutes compared to another solution.
Correct answer: A hypotonic environment- A. Osmotic pressure
- B. Turgor pressure
- C. Diffusion pressure deficit
- D. Water potential
Explanation: Normally, the movement of water molecules from a region of their higher concentration to a region of their low concentration through a…
Correct answer: Osmotic pressure243. Xerophytes have:
- A. Deep roots for water uptake
- B. Succulent stems for storage of water
- C. Few stomata to limit water loss
- D. All (A), (B) and (C)
Explanation: Xerophytes have the adaptations for reduced rate of transpiration. Many xerophytes possess small, thick leaves to limit water loss by…
Correct answer: All (A), (B) and (C)- A. Mesophyte
- B. Hydrophyte
- C. Both (A) and (B)
- D. Halophyte
Explanation: A hydrophyte is a plant that is adapted to grow in aquatic environments, such as lakes, rivers, or marshes.
Correct answer: Hydrophyte- A. High water potential
- B. Low osmotic pressure
- C. Low water potential
- D. All of these
Explanation: Water potential is a measure of the free energy of water in a system and determines the direction of water movement.
Correct answer: Low water potential- A. Osmoconformers
- B. Osmoregulators
- C. Thermoregulators
- D. Thermoconformors
Explanation: Animal body fluids are kept isotonic to the external environment, even for marine saltwater environment.
Correct answer: Osmoconformers- A. Osmoconformers
- B. Osmoregulators
- C. Thermoregulators
- D. Both (A) and (B)
Explanation: Osmoregulators are organisms that actively regulate and maintain a constant internal osmolarity, independent of the external environment.
Correct answer: Osmoregulators- A. Positive feedback
- B. Negative feedback
- C. Homeostatic imbalance
- D. None of these
Explanation: Negative feedback is a regulatory mechanism in biological systems that works to maintain stability and prevent excessive fluctuations.
Correct answer: Negative feedback- A. Produces dilute urine
- B. Have a hypertonic body
- C. Produces concentrated urine
- D. (A) and (B)
Explanation: The animals whose body fluid concentrations differ noticeably to the outside environment actively regulate to discharge excess water in…
Correct answer: (A) and (B)- A. Isotonic
- B. Hypotonic
- C. Hypertonic
- D. None of these
Explanation: An isotonic environment refers to a condition in which the concentration of solutes is the same inside and outside a cell or a biological…
Correct answer: Isotonic- A. Produces concentrated urine
- B. Have a hypotonic body
- C. Produces dilute urine
- D. (A) and (B)
Explanation: Animal body fluids are kept isotonic to the external environment, even for marine saltwater environment.
Correct answer: (A) and (B)252. Metabolic water is:
- A. Water outside the cells of animals
- B. Produced by oxidation of fats
- C. Useful to desert mammals
- D. (B) and (C)
Explanation: The evaporative loss of water leading to dehydration is the major problem for terrestrial life.
Correct answer: (B) and (C)- A. They lack nitrogenous waste
- B. Their metabolism is protein based
- C. Their nitrogenous products are recycled
- D. All (A), (B) and (C)
Explanation: Otherwise, overwhelmingly, nitrogenous waste metabolites constitute the excretory products.
Correct answer: Their nitrogenous products are recycled254. Plants excrete:
- A. Excess water
- B. Excess oxygen
- C. Excess carbon dioxide
- D. All (A), (B) and (C)
Explanation: In contrast, the mechanism of excretion in plants is diferent. Plants in their autotrophic mode of life produce oxygen and in metabolism…
Correct answer: All (A), (B) and (C)- A. Ammonia
- B. Urea
- C. Uric acid
- D. Creatinine
Explanation: Ammonia is a compound with the chemical formula NH3, a colorless gas with a pungent odor, commonly used in cleaning products and as a…
Correct answer: Ammonia- A. Ammonia
- B. Urea
- C. Uric acid
- D. Water
Explanation: Urea is a nitrogen-containing compound with the chemical formula CO(NH2)2, commonly used as a fertilizer and in the synthesis of plastics…
Correct answer: Urea- A. Ammonia
- B. Urea
- C. Uric acid
- D. All are highly toxic
Explanation: Uric acid is a waste product formed from the breakdown of purines in the body.
Correct answer: Uric acid- A. Stomata
- B. Injured tissue
- C. Lenticels
- D. Hydathodes
Explanation: Hydathodes are specialized structures in plant leaves that release excess water in the form of droplets.
Correct answer: Hydathodes- A. Protonephridia
- B. Flame cells
- C. Both (A) and (B)
- D. Metanephridia
Explanation: Planaria the animals of the group of flatworms have a simple tubular excretory system called protonephridium.
Correct answer: Both (A) and (B)- A. Protonephridia
- B. Coxal gland
- C. Malpighian tubules
- D. Metanephridia
Explanation: Metanephridia are more complex excretory structures found in some invertebrates, such as earthworms.
Correct answer: Metanephridia