1. Nucleotide: The fundamental building block of DNA and RNA. It consists of a sugar molecule, a phosphate group, and a nitrogenous base (adenine, guanine, cytosine, thymine, or uracil).
2. Gene: A segment of DNA that codes for a specific protein or functional RNA molecule.
3. Chromosome: A long, thread-like structure made up of tightly coiled DNA and associated proteins. Each chromosome contains multiple genes.
4. Genome: The complete set of genetic material (DNA) within an organism. It includes all the chromosomes.
So, the final sequence from smallest to largest is:
* Nucleotide
* Gene
* Chromosome
* Genome
