Atransmission electron microscope would be the best microscope choice to study a. structures smaller than cells b. single celled organisms c. plant leaves d. amphibian organs

The right answer is a. structures smaller than cells.

In the transmission electron microscope, electrons are emitted by heating a tungsten filament (or crystal of lanthanum hexaboride). These electrons are then accelerated with a voltage of between 200 and 1000 kV (1000 kV for the most expensive). Once the vacuum is in the cell, the electron beam is passed through a sample about 3 mm in diameter and less than 20 nanometers thick. Then this beam is focused with the help of magnetic lenses towards the screen or the photographic plate.

The operation of M.E.T is analogous to that of an optical microscope.

In light microscopy, a beam of photons is sent through a sample. This beam is then focused through optical lenses to the image plane of the lens. An enlarged image of the sample is observed.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."