In order to respond to a stimulus in the environment what must an organism do? Explain the role of phytochromes in determining plant responses to the environment. What is the stimulus that phytochromes respond to? How is the structure of a phytochrome related to its function? Explain how jetlag results from disruption of normal feedback loops at work in determining the circadian rhythms of humans. Explain the function of taxis in motile organisms Why do fungi only produce fruiting bodies at specific times? How is fruiting body formation controlled? How is the use of quorum sensing in bacteria advantageous? How are all of the responses discussed in this presentation similar? How do they differ?

(me out over the last several centuries, scientists have made the following broad observations while investigating several branches of the life sciences: -the fossil record shows that different types of organisms have existed at different times in earth's history. -many organisms have similar body structures that seem to be adapted to different ways of living in their environment. -organisms of different species often share similarities in stages of embryonic development. -many species share genetic similarities, and almost all organisms use the same basic building blocks to construct proteins. -often, the extent of two species' similarities can be predicted from their geographic closeness to each other. -a great deal of change has been observed among species that have experienced strong selective pressures through many generations. scientists have carefully considered and rigorously tested the observations listed above. when scientists offer a of these observations, they are making 1.) testable explanation, deductive explanation 2.) scientific interference, scientific law