The correct arrangement from smallest to largest is:
Gene, DNA, Chromosome.
However, this arrangement is based on the understanding that DNA is the material that makes up genes, and multiple genes are packaged together to form chromosomes. The most accurate understanding would consider the relationship: DNA is the foundational molecule, genes are segments of DNA that code for traits, and chromosomes are structures that hold many genes.
So while "Gene, DNA, Chromosome" is not a typical hierarchy in terms of structural organization, it reflects the logical order of the components involved.
If we are to consider just sizes and structural significance:
- A gene is a small segment of DNA.
- DNA molecules can have varying lengths, but ultimately several genes make up the long strands of DNA.
- A chromosome is made up of long strands of DNA and contains many genes.
That said, the proper relationship can be stated more clearly as: Gene < DNA < Chromosome in functional terms.