Refer to this portion of a dichotomous key for fish identification to answer the question. 1. (a) Has a single dorsal fin ® 5 (b) Has a double dorsal fin ® 2 5. (a) Has small fin on back near tail ® 6 (b) Has no fin on back near tail ® 7 6. (a) Has barbs near the mouth ® Catfish (b) Does not have barbs near the mouth ® 10 What do the numbers after the arrows represent? the number of the question that should be considered next the number of steps remaining before the organism is identified the number of questions that need to be answered the number of species that have the described characteristic

The negative change found inside the plasma membrane is created by potassium ions sodium ions hydrogen ions chlorine ions

For the strategies below, decide whether they are best described as demand-side solutions or supply-side solutions to meeting human needs for fresh water. remember that a demand-side solution reduces demand for fresh water, whereas a supply-side solution increases the supply of fresh water. (a) damming a river to create a reservoir (b) desalinating seawater (c) a nation invading a neighboring country to access their rivers (d) raising water prices for consumers and businesses (e) providing tax breaks for companies that use less water (f) replacing inefficient irrigation with more-efficient drip irrigation to grow crops (g) requiring low-flow showerheads in all new homes

Which of the following molecules could pass through the plasma membrane by simple diffusion? a. na+ ions b. glucose c. amino acids d. carbon dioxide