What is the reason that a modern transmission 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.
C
You might also like to view...
The most abundant genes in prokaryotic genomes are
A) those involved in metabolism. B) those involved in translation. C) those involved in transport. D) those involved in DNA replication.
Which of the following relationships is INCORRECT?
A. Maternal effect genes activate gap genes. B. Gap genes activate pair-rule genes. C. Pair-rule genes activate segment polarity genes. D. These relationships are all correct. E. Segment polarity genes activate pair-rule genes.
Imagine that you are using random PCR primers to amplify fragments of DNA. Would you expect to get more amplification products if you set the PCR machine at a higher or lower annealing temperature and why?
What will be an ideal response?
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by _____
A) hydrogen bonds B) nonpolar covalent bonds C) polar covalent bonds D) ionic bonds