How does ion composition of pre-urine differ from hemolymph?

Question

Quizplus · Accepted Answer

Pre-urine and hemolymph have a similar ion composition, as the Malpighian tubules selectively reabsorb certain ions while allowing others to pass through. Pre-urine is also not significantly higher in osmolarity compared to hemolymph, as the tubules actively transport ions in and out to maintain appropriate fluid balance. Option A is incorrect because pre-urine may not necessarily be significantly higher in osmolarity than hemolymph. Option B is also incorrect because hemolymph may not conserve its Cl⁻, as it may also have other ions that need to be maintained at appropriate levels. Option D is incorrect because protein pumps and channels in the Malpighian tubules do not actively concentrate Cl⁻ in the pre-urine, but instead selectively reabsorb and transport ions as needed.

How Does Ion Composition of Pre-Urine Differ from Hemolymph