For question 1: the sign, the exponent, and the fraction. Or...
fraction, exponent, and radix
You'll have to consider the context of your lecture to determine which answer your instructor might be looking for.
(Source: http://www3.ntu.edu.sg/home/ehchua/programming/java/DataRepresentation.html)
For question 2, I can think of only two important elements: and entry point, and an exit point. In the case of a for loop, a "step" element may be necessary, but not important.
Or, and interrupt in the loop might be considered important. For instance, you're looping thru a 100 element array looking for one particular set of data. Once you find the data, you no long need to finish the loop.
Hope this helps.