Gradual changes in the frequency of diseases over long periods are known as SECULAR TIME TRENDS. For example, the rate of mortality in USA due to coronary heart diseases over a period of time. Onset of puberty in girls is also a secular time trend.
Secular time trend is also referred as Secular Variation and Secular Drift.
Till this day We are always learning more and more so I think this can be helpful for future vaccines of diseases
Electron microscopes use _beam of electrons___ in order to allow for higher magnification and more detail when viewing specimens.
Explanation:
A beam of electrons has a shorter wavelength than normal light used in light microscopes, by approximately a factor of X 100000. Therefore, electrons microscope have the inherent attribute of having a very high resolution. They have been used to discover very small organelles in cells such as the ribosomes and mitochondria that cannot be clearly viewed even with the highest resolution in light microscopes.
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