Reorder by size
Cell, nucious DNA, chromosoma, gen, nucleoti

Explanation:

The arrangement below is from the smallest to the biggest

nucleotide → nucleus DNA → gene → chromosome → cell

The nucleotide is the smallest because it is what makes up the DNA, it is made up of a nitrogenous base, ribose sugar and a phosphate group.

Nucleus DNA follows because it is bigger than a nucleotide (as said earlier) but is singly found in the chromosome which is present in the nucleus.

The gene, which can be assumed to be the entire genome of the organism, involves both the chromosomal gene and the extrachromosomal gene (like the mitochondrial DNA).

Chromosome is made up of a DNA molecule and protein which makes it bigger than the Nucleus DNA and the gene because it contains several genes.

The Cell contains all the molecules/organelles mentioned above and as such is the largest among them all.

Note that the spellings the question are wrong and have been corrected in the answers provided

her next move would be to use agarose gel electrophoresis to separate the dna molecules of varying length and create a dna fingerprint.