Concept explainers
Introduction:
Excretion is the removal of waste from the body through the urinary system. Animal’s lifestyle is responsible for the type of nitrogenous waste in the form of excretion.
Answer to Problem 1MC
Correct answer:
Freshwater organisms excrete their feces in the form of ammonia. Therefore, option (a) is correct.
Option (a) is given as “Freshwater organisms are likely to excrete ammonia”.
Explanation of Solution
Justify reason for the correct statement:
Aquatic animals do not possess specific urinary system. They tend to excrete through gills and skin. So they are bound to excrete in the form of gas. Ammonia is the simplest form of nitrogenous waste in the form of gas.
Hence, option (a) is correct.
Justify reasons for the incorrect statements:
Option (b) is given as “ammonia is mostly excreted in urine”. Ammonia is a gas and urine contain water; additionally, the nitrogenous waste in urine is urea. Hence, it is a wrong answer.
Option (c) is given as “ammonia is the most complex of the three major nitrogenous wastes”. Ammonia is the simplest form of nitrogenous waste, urea is the most complex nitrogenous waste. Hence, it is a wrong answer.
Option (d) is given as “Humans convert ammonia to urea in the kidney”.
Conversion of ammonia into urea takes place inside the human body and this is called as urea cycle, but the site of the cycle is not the kidney, it is the liver. Hence, it is a wrong answer.
Hence, options (b), (c), and (d) are incorrect.
Ammonia is a gaseous form of nitrogenous waste. It is the simplest form, produced due to break down of amino acids in the human body. The liver performs the urea cycle to convert the ammonia into urea.
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Chapter 36 Solutions
Biology
- Humans excrete their excess nitrogenous wastes as a. uric acid crystals. b. compounds containing protein. c. ammonia. d. urea.arrow_forwardexplain why some desert animals excrete uric acid rather than ammoniaarrow_forwardWhich of the following is a nitrogenous waste product that is rarely the final product eliminated by animals inhabiting dry environments? A) Urea B) Nitric acid C) Nitrate D) Ammonia E) Uric Acidarrow_forward
- Human beings accumulate ________ before excreting nitrogenous waste. a. nitrogen b. ammonia c. urea d. uric acidarrow_forwardWhich of the following does not contribute to the process of filtration? (a) active transport by epithelial cells lining renal tubules (b) large surface area for filtration (c) low permeability of glomerular capillaries (d) high hydrostatic blood pressure in glomerular capillaries (e) podocytesarrow_forwardHumans excrete their excess nitrogenous wastes asa. uric acid crystals.b. protein.c. ammonia.d. urea.arrow_forward
- List the costs and benefits of the excretion of ammonia,urea, or uric acid as nitrogenous waste products.arrow_forwardIf a person has a very high protein diet, what substances/compounds would likely be increased in their urine? SELECT ALL THAT APPLY A. Protein B. Urea C. Nitrogen D. Amino Acidsarrow_forwardGiven: The liver and kidneys both extract molecules from the blood. a. How do their routes of excretion differ? (answer a)arrow_forward
- Many types of fishes live in freshwater. Generally, water moves by osmosis from the surrounding fresh water into the fish's body. This observation helps to explain which feature of the excretory systems of freshwater fishes? a. They tend to produce dilute, watery urine. b. They tend to produce concentrated, dark urine. c. They do not produce urine, but instead conserve or re-use nitrogenous wastes. d. They may produce either dilute or concentrated urine, depending on the activity of the fish.arrow_forwardWhy do mammals convert ammonia to urea rather than simply excreting it, as fish do?arrow_forwardWhat is in human urinearrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning