Answer:
nucleotide, gene, DNA, chromosome
Explanation:
A nucleotide consists of a nitrogenous base, pentose sugar, and a phosphate molecule. Several nucleotides are joined together by phosphodiester bonds and make long DNA strands.
A part of DNA that codes for a specific protein product and thereby, regulates a specific genetic trait is called a gene.
DNA is packed with help of packing proteins into a thread like structures called chromosome.
Hence, the ascending order of these structures is: "nucleotide, gene, DNA, chromosome".
