Biology Unit 5 Study Guide: Evolution. After his visit to the Galapagos Islands, Darwin came up with the theory of evolution. This theory stated that organisms change over time. The way that organisms change is through the process of natural selection. With examples, practice questions, and answers to help make evolution respiration easy to learn!
Moderate and extreme are relative terms. What many assume to be the normal conditions for life do not apply equally across all species. Habitability can be thought of in terms of the Goldilocks principle. For example, to survive people need an environment that is not too cold and not too hot. Ranges like this exist for other factors as well, such as pressure. However, what is just right for us and most other creatures can be too much or too little for some. Animals that live on the sea floor provide an illustrative example in this regard. Where people need submersibles to maintain their equilibria, creatures that natural selection has adapted to thrive in the ocean’s depths are right at home. Cold, highly pressurized environments are the norm for them. When deep sea creatures are brought to the surface through accident or scientific curiosity they often either melt, as with glacial ice worms, or fatally decompress, like with blobfish. In this way the term extremophile is a relative one and is used to describe organisms that live in environments that are extreme to us. Beyond their novelty, extremophiles are important objects of study as they challenge and expand our notions of life and its necessities.
History biography summary of Anton Van Leeuwenhoek and Robert Hooke, including their discoveries, cell theory as Fathers of Microbiology
Where does DNA transcription start and stop? In this lesson, we explain how DNA transcription works, the start and stop of transcription, and the 3 major transcription steps.
How does DNA transcription work in bacteria and prokaryotes? In this lesson, we explain how bacterial transcription works and its 3 basic steps: initiation, elongation, and termination.
This lesson discusses the size scales relevant to cell biology.
What makes something living? What are the characteristics of living things? All life has a common origin, but how do we know? This lesson examines various characteristics that define life and the origin of life. Various famous scientists and their biological discoveries are also discussed.