Warm up- What observations and assumptions can you make from this graph?

FRQ Practice Identify and describes three ways an increasing population degrades natural resources. Identify two ways resources are wasted and describe one realistic approach a city could take to discourage wasting of resources.

Scientific Method- Steps scientists use to find answers to their questions. (Research)

Use hypothesis to make testable predictions Identify a problem Find out what is known about the problem (literature search) Ask a question to be investigated Perform an experiment to answer the question and collect data Analyze data (check for patterns) Scientific law Well-accepted pattern in data Propose an hypothesis to explain data Use hypothesis to make testable predictions Figure 2.2 This diagram illustrates the general process that scientists use for discovering and testing ideas about how the natural world works. Perform an experiment to test predictions Test predictions Make testable Accept hypothesis Revise Scientific theory Well-tested and widely accepted hypothesis Stepped Art Fig. 2-2, p. 31

Hypothesis Hypothesis – a prediction of the outcome the experiment based on the information the scientist has gathered or already knows. It is written as an if then statement Ex> If there is lead pollution in drinking water then young children will develop learning disabilities.

Experiment must be performed in a very specific way. usually involve comparing two or more groups (the control group and the experimental group) to see how something (a variable) affects each group.

Designing a controlled experiment to test a hypothesis. Always have at least 2 (in APES 3) groups in your experiment so you can compare them  Control Group- LEAVE this alone- as much as possible, you use it to compare your experimental group to.   Experimental Group(s) - The group you are experimenting on. Dependent Variable- What the scientist is looking for, measuring, recording. The scientist has no control over this. Independent/ Experimental Variable—The variable that the scientist changes ON purpose. This is the ONE thing that is different between the experimental and control group.

Practice! You become an environmental activist and want to save the fishes and sea creatures. How would you set up an experiment to test what level of oil in sea water would cause mortality of sea turtles?

You want to find out if increasing the amount of oxygen in a lake will make fish live longer. Oxygen is measured in mg/L and about 9 mg of Oxygen/ L is normal or average for a freshwater lake

Theory If an experiment has been tested many times by many different scientists and the results are always the same then the scientist can consider the results to be a theory.