The unit of measurement that scientist use to determine the diameter of an animal cell ?

It is usually in micro-meters. Some use nano-meters.

The unit is a funny shaped 'u' sign

you can use meters, kilometers or picometers, and you'll get an equivalent answer.

If you mean to ask "what is the order of size of an animal cell" then micrometers (\mu m) is right.

Evil dead, \mu is called a "mu" (pronounced "mew" :)), It's a letter of the greek alphabet.

Lol okay, I did not know how to post symbols:confused:

hay u didn't mention ,whether animal is microscopic or not ?anyway the size of microscopic is taken by putting a small graduated scale in the lens used to be viewed amd the macros r measured by simple meter tapes and scales.
now about the unit... it completely deoends on the organism under observation... e.g if a virus then it will be nanometer ,bacteria =micrometer,animals =cnetimeters and inches... all purely depends on size.

Square footage measurement.