A negative control
a. would be any sample tested does not have the item that we are testing for.
O b. contains none of the experimental conditions/components and is usually plain water.
O c. should only be included in an experiment if it is suspected that the test is not working properly.
O d. all of the statements presented here are TRUE of negative controls
e.
should be used to establish a baseline value
O f. is used to ensure that the test being used is working such that we can observe positive results.
Answers
Answer:
Introduction
Biologists and other scientists use the scientific method to ask questions about the natural world. The scientific method begins with an observation, which leads the scientist to ask a question. She or he then comes up with a hypothesis, a testable explanation that addresses the question.
A hypothesis isn't necessarily right. Instead, it's a "best guess," and the scientist must test it to see if it's actually correct. Scientists test hypotheses by making predictions: if hypothesis \text XXstart text, X, end text is right, then \text YYstart text, Y, end text should be true. Then, they do experiments or make observations to see if the predictions are correct. If they are, the hypothesis is supported. If they aren't, it may be time for a new hypothesis.
How are hypotheses tested?
When possible, scientists test their hypotheses using controlled experiments. A controlled experiment is a scientific test done under controlled conditions, meaning that just one (or a few) factors are changed at a time, while all others are kept constant. We'll look closely at controlled experiments in the next section.
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