Essential Nutrients

How many of the following functions can be correctly correlated with loop of Henle ? A. Reabsorption of nearly all of the essential nutrients. B. Reabsorption in this segment is minimum. C. A significant role in the maintenance of high osmolarity of medullary interstitial fluid. D. Reabsorption of 70-80 percent of electrolytes and water. E. Conditional reabsorption of Na^(+) .

Which of theses statements about proximal convoluted tubule is/are true? I. it is lined by simple columnar brush border epithelium which increases the surface area for reabsorption. II Nearly all of the essential nutrients and 70%-80% of electrolytes and water are reabsorbed by this segment. III. It selectively secretes hydrogen ions, ammonia and potassium ions into the filtrate. IV. It is the most convoluted part of the nephron and is present in the medullary region of the kidney.

Nearly all the essential nutrient is are reabsorbed at

Insectivorous plants digest insects to get an essential nutrient. Other plants generally get this nutrient from the soil. What is this nutrient ?