Question 29

Urea is excreted by sweat glands in response to the breakdown of proteins and the formation of ammonia.

Urea is a waste product that results from the metabolism of proteins. When proteins are broken down, ammonia is produced, which is then converted into urea for safer excretion through sweat glands.

A) Water

While water is a major component of sweat and is excreted to help regulate body temperature, it is not a product of protein metabolism. Therefore, it does not relate to the breakdown of proteins or the formation of ammonia.

B) Sebum

Sebum is an oily substance produced by sebaceous glands, not sweat glands. It serves to lubricate the skin and hair but is unrelated to the excretion of waste products resulting from protein breakdown.

C) Urea

Urea is indeed a waste product formed from the breakdown of proteins. It is excreted through sweat glands, making this option correct in the context of how the body eliminates nitrogenous waste.

D) Lysozymes

Lysozymes are enzymes that help defend against bacterial infections and are found in various bodily fluids, but they are not excreted through sweat glands in response to protein breakdown. This makes this option incorrect in relation to the question.

Conclusion

Urea is the correct answer because it is specifically linked to the metabolic process of protein breakdown and is excreted through sweat glands as a means of removing excess nitrogen from the body. Other options, while related to body processes, do not pertain to the excretion of waste from protein metabolism, thereby confirming that they are incorrect.