NEET Biology: Modes of excretion-Ammonotelism Practice Questions
15 free multiple-choice questions on Modes of excretion-Ammonotelism (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. In organisms that exhibit ammonotelism, ammonia is typically excreted through which major excretory organ?
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Correct answer: A — Kidneys
In many invertebrates and lower vertebrates relying on ammonotelism, the kidneys (or equivalent excretory organs) are responsible for filtering and eliminating nitrogenous wastes, including ammonia.
Q2. Which metabolic process leads to the formation of ammonia as an excretory product in many organisms?
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Correct answer: A — Protein metabolism
The breakdown of amino acids (protein metabolism) through deamination is the primary source of ammonia excretion in most organisms, especially those relying on ammonotelism for nitrogenous waste elimination.
Q3. Ammonotelism is characterized by the excretion of which type of nitrogenous compound?
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Correct answer: A — Ammonia
Ammonotelism is the mode of excretion where the nitrogenous waste is excreted predominantly in the form of ammonia.
Q4. Which process describes the conversion of ammonia into urea for excretion in mammals?
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Correct answer: D — Ureotelism
The conversion of ammonia into urea is characteristic of ureotelism, which is the primary mode for mammals.
Q5. The process of converting ammonia into urea is a key feature of which excretion mode?
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Correct answer: D — Ureotelism
The conversion of ammonia into urea is the hallmark of ureotelism, which is the predominant mode of excretion in mammals.
Q6. What is the main metabolic pathway responsible for the formation of ammonia during protein catabolism?
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Correct answer: D — Deamination of amino acids
Ammonia is formed when amino acids are deaminated (broken down) to release nitrogen, a process known as deamination.
Q7. Terrestrial animals, like mammals and birds, primarily utilize which mode of excretion for nitrogenous waste elimination?
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Correct answer: D — Ureotelism
Terrestrial animals efficiently excrete nitrogenous waste as urea, which is more water-soluble and less toxic than ammonia, making ureotelism dominant.
Q8. If an organism has a high rate of protein catabolism, what is the immediate consequence regarding nitrogenous waste management?
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Correct answer: B — Increased excretion of ammonia
Increased protein catabolism results in the breakdown of amino acids, which releases ammonia as a waste product. Therefore, a high rate of protein breakdown directly leads to increased ammonia excretion.
Q9. In ammonotelism, ammonia is generally highly toxic to the body. How is this toxicity managed?
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Correct answer: D — It is converted into urea
Ammonia is highly toxic. In organisms that utilize ammonotelism, ammonia is often converted into less toxic forms (like urea) or excreted via specialized pathways.
Q10. In aquatic organisms, the primary route for eliminating nitrogenous waste, often involving high ammonia excretion, is primarily through which medium?
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Correct answer: B — Excretion via gills
Aquatic organisms, especially fish, excrete nitrogenous wastes like ammonia dissolved in water through their gills and urine, making the water the primary elimination medium.
Q11. Which of the following substances is the primary excretory product in ammonotelism?
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Correct answer: B — Ammonium ions (NH4+ )
In ammonotelism, the primary nitrogenous waste excreted by terrestrial organisms is ammonia (NH3/NH4+), which is then excreted, often as ammonium ions, in the urine or gills.
Q12. In aquatic organisms utilizing ammonotelism, the ammonia excreted dissolves readily in which medium?
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Correct answer: B — Water
Since ammonotelism involves direct excretion into the surrounding environment (like water), ammonia dissolves readily in the aquatic medium.
Q13. Which of the following reflects the primary nitrogenous waste excreted in mammals that utilize the urea cycle (a variation of ammonotelism)?
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Correct answer: D — Urea
Mammals primarily use the urea cycle to convert toxic ammonia into less toxic urea for excretion via urine.
Q14. The excretion of ammonia is crucial for balancing nitrogen metabolism, primarily because ammonia is the direct product of the breakdown of which biological macromolecules?
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Correct answer: D — Proteins
Ammonia is directly derived from the breakdown (catabolism) of amino acids (proteins).
Q15. In terrestrial animals, the elimination of excess ammonia often leads to the formation of which compound in the urine?
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Correct answer: A — Urea
In terrestrial animals that employ the urea cycle (a form of ammonotelism), ammonia is converted into urea for safer excretion in the urine.
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