He kidneys of terrestrial mammals conserve water in the body by concentrating urine. the osmolarity of human blood is 300 mosm/l, but human urine is generally about 1200 mosm/l. the loop of henle and the collecting duct are instrumental in maintaining osmotic gradients that make the concentration of urine possible. complete the diagram below using the following steps: place the pink labels, which indicate interstitial fluid osmolarity in mosm/l, onto the correct pink targets. (note that the numbers inside the nephron and collecting duct indicate the osmolarity of the filtrate at those different points.) place a red arrow to indicate active transport or a purple arrow to indicate passive transport onto the remaining targets. do h2o, nacl, and urea experience active transport, passive transport, or both? keep in mind that the nephron's epithelium exhibits varying permeability to water and solutes along its length. labels can be used once,

The diagram is answered below with arrows and labels.

1)To place the pink labels you need to know that the osmolarity will increase  gradually from cortex to outer medulla to inter medula. The lower in the inter medulla , the higher the osmolarity. This causes a considerable amount of water to constantly flow from the interior to the exterior of the descending branch of the Henle loop

2) red arrows: active transport occurs in the upward branch of the loop Henle. NaCl goes from the interior to the outside of the loop. This process also happens in distal tubules, while Na+ goes from inside to outside, potassium does the opposite. Purple: the rest of nephron goes through passive transport.

3) like i mentioned before, active transport occurs in the upward branch of the loop Henle and in distal tubules, and make sodium ions go from inside to outside. Through out the nephron the water is constantly flowing from the interior to the exterior.
Ureia: passive transport
water: passive transport
NaCl: both

The right answer is b hydrogen bonds!