gene,chromosome,dna,nucleus, and cell
if you look it up you will get the following stated below
"nitrogenous base, nucleotide, codon, gene, chromosome, nucleus, and cell"\
an easy way to remember it will to be
the gene tells you what it would be you get one from mom and one from dad
you need genes to link and make chromosomes
chromosomes to link into strands of dna
there is dna in the nucleus and the nucleus in inside the cell.
hopefully this helps.