What is a scientific theory? Question 3 options:

a testable guess that predicts how variables are related in an experiment or model system, often expressed as an if-then statement

an explanation of that natural world that has been repeatedly confirmed through observation and experimentation and is accepted by the scientific community

a guess or prediction about the natural world with no evidence that some people believe and some people do not believe

the description of the relationships between observable phenomena

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

Ivan is looking at a cross section of a stem taken from a vascular plant. he sees two different types of vascular tissue: the xylem, which is closer to the center of the stem, and the phloem, located around the xylem, closer to the outside of the stem. how do these two structures work together in a living plant?

What are 3 reasons that natural selection occurs