Which one of the following is not a part of a renal pyramid?

The brush border is a characteristic of ..........

The descending limb of the loop of Henle is ..........

$A$ large quantity of fluid is filtered every day by the nephrons in the kidneys. Only about $1\%$ of it is excreted as urine. The remaining $99\%$ of the filtrate

In which part of the nephron does the maximum reabsorption occur?

Active transport takes place in the absorption of