Onion leaves are green. Students testing onion leaves for the presence of starch used the method shown in the four stages of Fig 20.1 Explain the reasons for the details shown in each stage.
reasons for stage 1 .
reasons for stage 2 .
reasons for stage 3 .
reasons for stage 4 .

Which format should he use to present his data?

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 is an eon in the time scale? phanerozoic proterozoic archean all of the above