$I.$ Glucose $II.$ Amino acid $III.$ $Na^+$ $IV.$ Nitrogenous waste
Which of these are reabsorbed actively in the nephron?
Choose the correct option.

Given below are two statements:
Statement $I$: In the nephron,the descending limb of the loop of Henle is impermeable to water and permeable to electrolytes.
Statement $II$: The proximal convoluted tubule is lined by simple columnar brush border epithelium and increases the surface area for reabsorption.
In the light of the above statements,choose the correct answer from the options given below:

Nearly all of the essential nutrients,and $70-80\%$ of electrolytes and water are reabsorbed in the

Choose the mismatched part of the nephron with its function.

Passive transport occurs in the case of

Explain the function of collecting tubules.