Question
Biology Question on Human Excretory System
Human urine contains
A
95% water, 2.6% urea, 2% salts and some uric acid
B
99% water and 1% urea
C
92% water and 8% salts
D
90% water, 8% uric acid and 2% proteins
Answer
95% water, 2.6% urea, 2% salts and some uric acid
Explanation
Solution
Urine is a liquid produced by the kidneys to remove waste products from the bloodstream. Human urine is transparent, yellowish in colour and variable in chemical composition. It consists primarily of water (95%), with organic solutes including urea (2.6%), creatinine, uric acid, and trace amounts of enzymes, carbohydrates, hormones, fatty acids, pigments, and mucins, and inorganic ions such as sodium (Na), potassium (K), chloride (Cl), magnesium (Mg), calcium (Ca), ammonium (NH ), sulfates (SO ), and phosphates (PO ).