Final answer:
The osmolarity of the filtrate in the ascending limb of the loop of Henle would decrease if active transport of NaCl stopped. In the realm of optics, the scale of contrast is influenced by interference patterns, with contrast varying with the thickness of air layers between thin films.
Step-by-step explanation:
When considering the scenario presented in the question about the loop of Henle within the kidney, the focus is on what would happen to the osmolarity of the filtrate in the ascending limb if the active transport of NaCl stopped. The correct answer is that the filtrate osmolarity would decrease. This is because active transport is responsible for moving NaCl out of the filtrate and into the surrounding interstitial fluid, which helps to concentrate the urine. If active transport were to cease, NaCl would not be removed from the filtrate, leading to a less concentrated, or lower osmolarity, filtrate.Addressing a broader context, including filtration and the scale of contrast in other circumstances such as light interference, the scale of contrast typically refers to the degree to which different levels of brightness or color can be distinguished. In the context of thin-film interference, for instance, separating microscope slides with a wedge of air between them produces dark bands and repeating rainbow colors. This is an instance where constructive and destructive interference affect the scale of contrast, making bands harder to see as the thickness of the air layer increases.