The Hertzsprung-Russell diagram is one of the most important tools in the study of stellar evolution. Developed independently in the early 1900's by Ejnar Hertzsprung and Henry Norris Russell, it plots the temperature of stars against their luminosity (the theoretical HR diagram), or the color of stars against their absolute magnitude
Depending on its initial mass, every star goes through specific evolutionary stages dictated by its internal structure and how it produces energy. Each of these stages corresponds to a change in the temperature and luminosity of the star, which can be seen to move to different regions on the HR diagram as it evolves. This reveals the true power of the HR diagram – astronomers can know a star’s internal structure and evolutionary stage simply by determining its position in the diagram.
The Hertzsprung-Russell diagram the various stages of stellar evolution. By far the most prominent feature is the main sequence (grey), which runs from the upper left (hot, luminous stars) to the bottom right (cool, faint stars) of the diagram. The giant branch and supergiant stars lie above the main sequence, and white dwarfs are found below it.
B. Homeostasis . homeostasis is the process via which organisms maintain their internal milleu.
Answer: Prokaryotes, archaea, protists, fungi, algae.
Explanation:I don’t think there are any single celled organisms that are today classified as animals. So basically I just left the animal kingdom out. Both metazoans and sponges are for the most part multicellular.
The correct answer is: by analyzing her average test scores after nights with different amounts of sleep.
This is the best way to approve her hypothesis, because she can compare the results of the tests influenced by different amounts of sleep.
The independent variable (the one that is changed by the scientist) in this hypothesis would be hours of sleep. The dependent variable (the one that is observed and that responds to the change made by the independent variable) would be result of test.
Autonomic nervous system (ANS) is the branch of the nervous system that provides unconscious control of basic body processes that is consists of two divisions; the sympathetic and parasympathetic. These two divisions have opposing effects on the internal organs they innervate. The Parasympathetic nervous system is the division that balances the actions of the sympathetic nervous system by slowing body processes, returning the body to homeostasis once a stressor has passed. The Sympathetic nervous system is the emergency system. Its major function is the fight-or-flight response in reaction to a threat. It speed-up key body processes to prepare the body for physical action.