In the Malpighian tubules of an insect (blind,threadlike excretory tubule attached to the gut of an insect),salt molecules are actively transferred from body fluids to the inside of the tubule.Which of the following is NOT true?
A)Water is also "pulled" by osmosis into the Malpighian tubule.
B)The concentration of salt is normally higher in the body fluids than it is inside the tubule.
C)The process decreases the salt concentration of the body fluids.
D)Insects must excrete excess salt through the Malpighian tubules.
E)The tubules have the same tonicity as the body fluids.

Question

Quizplus · Accepted Answer

The statement "The tubules have the same tonicity as the body fluids" is not true. The Malpighian tubules have a higher salt concentration inside compared to the body fluids, which causes the active transport of salt molecules from the body fluids to the tubule. This difference in tonicity is essential for the function of the Malpighian tubules in excreting excess salt from the insect's body.

In the Malpighian Tubules of an Insect (Blind,threadlike Excretory Tubule