Imagine a different system in which toads had a wide range of variation in color. In some ponds, most of the toads are light in color. In other ponds, the average color is fairly dark. From the options below, select which represent TESTABLE hypotheses that could explain this difference in coloration. A. A predator that is present in some ponds prefers one color to the other. B. Female toads in some ponds prefer darker toads, while females in another pond prefer lighter toads. C. Toad color is determined by food quality, which varies pond to pond. D. Toads can change their color, based on their stress level.

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.

answer; endoplasmic reticulum;