What is the criterion for DNA fragments movement on agarose gel during gel electrophoresis ?

The DNA fragments separated on an agarose gel can be visualised after staining with

(1) bromophenol blue

(2) acetocarmine

(3) aniline blue 

(4) ethidium bromide

DNA fragments generated by the restriction endonucleases in a chemical reaction can be separated by

Agarose extracted from sea weeds finds use in

1. tissue culture

2. PCR

3. gel electrophoresis

4. spectrophotometry

Gel electrophoresis is used for

1. cutting of DNA into fragments

2. separation of DNA fragments according to their size

3. construction of recombinant DNA by joining with cloning vectors

4. isolation of DNA molecule