Bio 141 Chapter 1
How do an observation, a hypothesis, and a prediction differ?
What makes a hypothesis useful for scientific investigations that try to explain the natural world?
Give examples of hypotheses that are and are not scientifically useful. State the null hypothesis that corresponds to each of your examples.
What is the difference between a hypothesis and a scientific Theory?
A scientific theory is an explanation for a very general class of phenomena or observation that are supported by a wide variety of evidence.
A hypothesis is only a testable statement to explain a phenomenon or a set of observations.
Theory is also usually used to explain broad patterns while a hypothesis is used to explain more tightly focused questions. A theory replaces a hypothesis after testing confirms hypothesis. A theory also serves as the framework for the development of new hypothesis.
What are the two components of Cell Theory and of the Theory of Evolution by Natural Selection? What are the two conditions required by the process component of evolutionary theory?
Two conditions required by the process component of evolutionary theory: Characteristics have to be heritable, traits allow people to produce offspring and increased fitness
What is the hypothesis of Spontaneous Generation and how does Cell Theory challenge that hypothesis? In the Pasteur experiment two types of flasks were used. For each flask, what is the outcome predicted by Spontaneous Generation? By Cell Theory? Why did Pasteur use a swan-necked flask? Why did he boil the broth in both flasks?
What are the similarities and differences between organisms in the three domains of life? What do the nodes and branches of a phylogenetic tree indicate? How can genetic information be used to generate a phylogenetic tree?
What are the key steps in hypothesis testing? What are the essential elements of a scientific experiment? Design an experiment to test the hypothesis that squirrels prefer nuts over chicken wings.
1. State the hypothesis as precisely as possible and the predictions it makes
2. Design an observational or experimental study that is capable of testing those predictions
Large sample size, include control groups, have constant/equivalent experimental conditions, repeatability
Describe the two hypotheses proposed to account for the observation that giraffes have long necks. What are the predictions of the first, “food competition” hypothesis? What evidence is cited in your textbook that supports one or more of these predictions? What are the observations that gave rise to the alternative, sexual competition hypothesis? What evidence is cited that is consistent with the second hypothesis? Do biologist agree that there is sufficient evidence to reject or confirm either hypothesis? Could both hypotheses be true?