Summary of this article

Explain the difference between DNA, genes, and chromosomes in an easy-to-understand manner. Deepen your basic knowledge by explaining in detail the role, structure, and function of each in the body.

DNA

STRUCTURE: DNA (deoxyribonucleic acid) is a molecule with a double helical structure, consisting of four bases (adenine, thymine, guanine and cytosine).
Role: blueprint that stores genetic information and directs cellular activity.It is replicated in the cell and transmits genetic information from parent to child.
The structure of DNA is shaped like a ‘double helix’. This resembles a twisted ladder: DNA is made up of four bases (adenine (A), thymine (T), guanine (G) and cytosine (C)), each of which forms a pair. A is linked to T and G to C. A is linked to T and G to C, respectively. These pairs correspond to the ‘rungs of the ladder’ of DNA. The structure of the double helix is important for keeping genetic information stable within the cell.

Gene

Structure: the portion of a particular base sequence in DNA.
Role: coding unit for a specific protein. Determines traits (e.g. eye colour, blood type).

Chromosome

Structure: DNA tightly folded together with proteins. Human cells have 46 chromosomes.
Role: distributes DNA appropriately during cell division. Contains a large number of genes in succession.

Summary

DNA is the basic molecule containing all genetic information.
Genes are specific parts of DNA that carry out specific functions.
Chromosomes are condensed structures of DNA, which are clusters of genes.

医師監修監修日：2024年8月30日

岡博史（おかひろし）

医師・医学博士／ヒロクリニック統括院長

YouTubeチャンネルなどを通じて、遺伝子やNIPT（新型出生前診断）についてわかりやすく発信しています。

略歴

1996年慶應義塾大学医学部卒業
2004年慶應義塾大学医学博士号取得
2005年慶應義塾大学皮膚科学教室助手
2008年ヒロ皮フ形成クリニック開業
2009年医療法人社団福美会理事長
2015年医療法人社団福美会理事

資格・所属

CAPラボディレクター
日本皮膚科学会皮膚科専門医
日本医師会産業医
東京衛生検査所指導監督医

発信・関連リンク

この記事は、ヒロクリニックNIPPTの編集・監修体制にもとづき、資格を持つ医師が内容を確認しています。

医師監修監修日：2024年8月30日

堤修一（つつみしゅういち）

医師・医学博士／ヒロクリニック博多駅前院院長

略歴

1993年東京大学医学部医学科卒業
2016〜2019年東京大学先端科学技術研究センター准教授

発信・関連リンク

プロフィール詳細

この記事は、ヒロクリニックNIPPTの編集・監修体制にもとづき、資格を持つ医師が内容を確認しています。

参考文献

Watson JD, Crick FH. Molecular structure of nucleic acids; a structure for deoxyribose nucleic acid. Nature. 1953 Apr 25;171(4356):737-8.
Tjio JH, Levan A. The chromosome number of man. Hereditas. 1956 Jan;42(1-2):1-6.
Lo YM, Corbetta N, Chamberlain PF, Rai V, Sargent IL, Redman CW, et al. Presence of fetal DNA in maternal plasma and serum. Lancet. 1997 Aug 16;350(9076):485-7.
MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); [updated 2020 Jun 24; cited 2023 Oct 26]. What is DNA? Available from: https://medlineplus.gov/genetics/understanding/basics/dna/
MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); [updated 2020 Jun 24; cited 2023 Oct 26]. What is a gene? Available from: https://medlineplus.gov/genetics/understanding/basics/gene/
MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); [updated 2020 Jun 24; cited 2023 Oct 26]. What is a chromosome? Available from: https://medlineplus.gov/genetics/understanding/basics/chromosome/