What is the reason that a modern electron microscope (TEM)can resolve biological images to the subnanometer level, as opposed to tens of nanometers achievable for the best super-resolution light microscope?
A) The focal length of the electron microscope is significantly longer. B) Contrast is enhanced by staining with atoms of heavy metal. C) Electron beams have much shorter wavelengths than visible light. D) The electron microscope has a much greater ratio of image size to real size. E) The electron microscope cannot image whole cells at one time.
Which of the following correctly lists the order in which cellular components will be found in the pellet when homogenized cells are treated with increasingly rapid spins in a centrifuge?
A) ribosomes, nucleus, mitochondria B) chloroplasts, ribosomes, vacuoles C) nucleus, ribosomes, chloroplasts D) vacuoles, ribosomes, nucleus E) nucleus, mitochondria, ribosomes
When biologists wish to study the internal ultrastructure of cells, they can achieve the finest resolution by using
A) a phase-contrast light microscope. B) a scanning electron microscope. C) a transmission electronic microscope. D) a confocal fluorescence microscope. E) a super-resolution fluorescence microscope.