DNA and genes: What is the difference?
ca. 20 Minuten
The difference between DNA and genes is a difference in scale: DNA is the molecule, and a gene is a section of it. The storage medium and the file on it are not the same thing. In everyday usage, however, both words are used synonymously - and that is where most misunderstandings arise.
In between are other terms: A chromosome is a packaged DNA molecule, the genome is all the DNA in a cell, an allele is a variant of a gene, and an SNP is the replacement of a single letter.
This article sorts out the hierarchy of terms from base to genome, shows how a gene gives rise to a trait, and explains what a gene variant does - and does not - tell us about an individual.
What to expect in this article
What exactly is a gene?
What is DNA made of, and how is it structured?
How are chromosomes, genomes, and genetic material related?
How does a gene become a trait?
DNA, gene, chromosome, genome, and allele compared
What are alleles and SNPs?
Genetics or epigenetics - what's the difference?
What misconceptions about DNA and genes persist?
The key terms, each in one sentence
How mybody® uses these terms in DNA testing
Putting it in perspective: What a gene variant does—and doesn't—tell you
Conclusion
Frequently asked questions (FAQ)
Sources
What is the difference between DNA and genes?
DNA is a molecule; a gene is a piece of it. So the terms do not describe two things side by side, but two levels layered on top of each other. When people say “DNA,” they mean the material; when they say “gene,” they mean a functional unit on that material. The analogy with text goes a long way: DNA is the paper and letters, while a gene is a paragraph with its own meaning.
The difference in size is considerable. According to MedlinePlus Genetics of the U.S. National Library of Medicine (2024), human genes range in length from a few hundred base pairs to more than two million base pairs. All genes together make up only a small part of the DNA present - the rest has other functions.
Key point: DNA and genes are not opposites, but different levels: DNA is the carrier, and a gene is a functional section of that carrier. All genes consist of DNA - but by no means is all DNA a gene.
What exactly is a gene?
A gene is the section of DNA that contains the information for a specific product - in most cases, a protein or a protein building block. It is also the smallest unit passed on as a whole. That is why genetics considers the gene the basic unit of inheritance.
“The gene is considered the basic unit of inheritance. Genes are passed from parents to offspring and contain the information needed to specify physical and biological traits. Most genes code for specific proteins, or segments of proteins, which have differing functions within the body.”
In other words, the gene is considered the basic unit of inheritance; genes are passed from parents to offspring and contain the information that determines physical and biological traits. Most genes code for specific proteins or parts of proteins with different functions in the body.
How a gene is structured internally
A gene is not one continuous block. It consists of exons - the sections whose information ultimately ends up in the protein - and introns, which are read but cut out again before the protein is made. Before them is the promoter, a starting region where the reading machinery attaches. Further away are enhancers, which boost reading, and silencers, which suppress it.
The position of a gene on a chromosome is called its locus. This location is the same in all people - only the text there differs. That is the starting point for every genetic analysis.
What is DNA made of, and how is it structured?
DNA - short for deoxyribonucleic acid, also called DNS in German - is a long chain molecule made up of four building blocks. These four bases are called adenine (A), thymine (T), guanine (G), and cytosine (C). Their sequence is the actual information. MedlinePlus Genetics (National Library of Medicine, 2021) describes DNA as the hereditary material in humans and nearly all other organisms.
Two such strands lie opposite each other and twist into the familiar double helix. A always pairs with T, and G always pairs with C. This fixed rule is why DNA can replicate at all: each strand contains the complete instructions for its complementary strand.
Base
The individual letter: A, T, G, or C. Two opposing bases form a base pair.
DNA
The text: a double helix made up of millions of base pairs lined up in sequence.
Gene
The paragraph: a distinct section with its own function, usually instructions for building a protein.
Chromosome
The chapter: a single DNA molecule wrapped around proteins and tightly packed.
Genome
The whole book: the complete DNA complement of a cell, all the chromosomes together.
Why most DNA is not a gene
The proportion of DNA that actually codes for proteins is surprisingly small. According to MedlinePlus Genetics (National Library of Medicine, 2021), only about one percent of DNA consists of protein-coding genes; the remaining 99 percent is non-coding. The term “junk DNA,” which was long used for this, is misleading.
According to the same source, non-coding DNA includes promoters, enhancers, silencers, and insulators, as well as genes for tRNA, rRNA, and microRNA, and telomeres. Much of it controls when and how strongly a gene is read - the direction, not the text.
How are chromosomes, genomes, and genetic material related?
A chromosome is not a separate substance, but a packaging form: a single, very long DNA molecule wrapped around histone proteins and thereby tightly compacted. Without this packaging, the DNA from a single cell would not fit inside its nucleus.
These chromosomes occur in pairs—one from the father, one from the mother. According to MedlinePlus Genetics (National Library of Medicine, 2021), each human cell normally contains 23 pairs of chromosomes, for a total of 46 chromosomes. 22 pairs are autosomes; the 23rd pair are the sex chromosomes.
Source: MedlinePlus Genetics, U.S. National Library of Medicine (National Institutes of Health), 2021 and 2024
Anyone who equates “DNA” with “genes” overlooks around 99 percent of the material.
Genome and genetic material—what’s the difference?
The genome is the complete DNA makeup of a cell: all 46 chromosomes in the cell nucleus plus the small, circular DNA in the mitochondria. Genetic material is the everyday English term for it and essentially means the same thing, but emphasizes its transmission to the next generation.
Key point: Base, DNA, gene, chromosome, genome are five zoom levels of the same material—from a single letter to the complete library. No term replaces another.
How does a gene become a trait?
Two translation steps separate a sequence of letters from a visible trait. In the first, transcription, the gene segment is copied into a mobile working copy called messenger RNA. It leaves the cell nucleus. In the second step, translation, ribosomes read this copy and join amino acids into a chain. Each set of three bases forms a code word for an amino acid.
Genotype and phenotype are two different things
The genotype is the genetic makeup at a particular location—in other words, which variant someone carries. The phenotype is what actually manifests: height, enzyme activity, hair color, a lab result. Everything that affects how the information is read lies between the two.
A relatable example is the digestion of milk sugar: According to MedlinePlus Genetics (National Library of Medicine, 2023), the LCT gene contains the instructions for making the enzyme lactase. In many people, its activity decreases after infancy—the genotype stays the same, but the phenotype changes.
Two more concepts come into play: penetrance describes the proportion of carriers in whom the expected trait appears at all, while expressivity describes how strongly it manifests. Neither is rarely one hundred percent—so the leap from a test result to a prediction is so tricky.
DNA, gene, chromosome, genome, and allele compared
Five terms, four recurring questions: What is it, how big is it, where is it located, and why does it matter? The comparison shows that these are not competing concepts, but nested levels.
| Term | What is it? | Approximate size | Where in the body | Why it matters |
|---|---|---|---|---|
| DNA | The molecule itself: a double helix made up of the bases A, T, G, and C | Approx. 3 billion bases per cell's nuclear complement (NLM, 2021) | In the nucleus of nearly every body cell, and also in the mitochondria | Carrier material for all information; basis of every sequencing process |
| Gene | A functional section of DNA containing instructions, usually for a protein | A few hundred to over 2 million base pairs (NLM, 2024) | At a fixed location (locus) on a specific chromosome | Smallest inherited functional unit; reference point in test results |
| Chromosome | A single DNA molecule wrapped around histones and tightly packed | 23 pairs, 46 chromosomes in total per cell (NLM, 2021) | In the cell nucleus; visible under a microscope during cell division | Arranges genes spatially; explains why traits are inherited in pairs |
| Genome | The complete DNA complement of a cell, all chromosomes together | Contains approx. 19,900 protein-coding genes (NLM, 2024) | Present identically in practically every body cell | Frame of reference for statements such as “one percent of DNA codes for proteins” |
| Allele | One of several possible versions of the same gene | Difference often just a single base; two alleles per locus | At the same locus on the two chromosomes in a pair | Explains individual differences; what a DNA test determines |
This leads to a rule of thumb: A test does not “read” a gene; it determines which allele is present at defined positions. The level at which people differ is the bottom row.
What are alleles and SNPs?
An allele is a variant of a gene. Because chromosomes occur in pairs, each person carries two alleles at each locus—one from the father and one from the mother. If both are the same, the person is homozygous; if they differ, heterozygous.
Which allele prevails in a trait depends on the inheritance pattern. A dominant allele shapes the trait even when present in a single copy, while a recessive allele does so only when present in two copies. For many traits, however, both alleles contribute to some extent—the strict dominance described in textbooks is more the exception than the rule.
SNPs: a single-letter substitution
An SNP (single nucleotide polymorphism, pronounced “snip”) is the smallest conceivable type of variant: at a particular position, some people have a different letter from others. A single character in a billion-letter text - which, depending on where it occurs, can have noticeable effects or none at all.
According to MedlinePlus Genetics (National Library of Medicine, 2022), SNPs are the most common form of genetic variation in humans; a person's genome contains around four to five million SNPs, on average about one per 1,000 nucleotides. Most of them are in non-coding regions.
In brief
An allele is a variant of a gene; each person carries two at each locus, one from each parent.
An SNP is the smallest variant of all: the substitution of a single base. A person's genome contains around four to five million SNPs (National Library of Medicine, 2022).
SNPs are markers of statistical associations at the group level - they are neither a diagnosis nor a prediction for an individual.
Genetics or epigenetics - what's the difference?
Genetics deals with the text: which sequence of bases is present and how it is passed on. Epigenetics deals with the direction: which sections are read in a particular cell at a particular time. The key point is that the sequence of bases itself remains unchanged.
MedlinePlus Genetics (National Library of Medicine, 2021) defines the epigenome as the set of modifications that regulate gene activity - that is, gene expression. Two mechanisms are most prominent.
In DNA methylation, methyl groups are attached to DNA. According to the same source, a gene with methyl groups attached is switched off or silenced, so no protein is produced from that gene. In histone modification, the packaging proteins are chemically altered; this affects how tightly the DNA is wrapped around the histones - and therefore whether a gene can be switched on or off.
Key point: Genetics is the text; epigenetics is the stage direction. Lifestyle affects the direction, not the text - the sequence of bases itself stays the same for life.
What misconceptions about DNA and genes persist?
Three ideas keep coming up. All three sound plausible and fall short - usually because they skip a level on the ladder of concepts.
The key terms, each in one sentence
A short genetics glossary
- ✓ Base – one of the four letters A, T, G, or C that make up DNA
- ✓ DNA – deoxyribonucleic acid, the molecule that carries genetic information
- ✓ Gene – a functional section of DNA, usually containing the instructions for making a protein
- ✓ Allele – one of several possible versions of the same gene
- ✓ SNP – a variant in which exactly one base is replaced
- ✓ Chromosome – a tightly packed DNA molecule; humans have 23 pairs
- ✓ Genome – the complete DNA makeup of a cell
- ✓ Epigenetics – the regulation of gene activity without changing the base sequence
Where this article ends—and what to read next
This article clarifies the terminology. It deliberately does not address what a test reveals or costs—there are two separate articles for that.
For details on what an analysis actually evaluates and how reliable the results are, see the article What does a DNA metabolism test tell you?.
The article DNA analysis for weight loss: costs explains how prices are determined and what distinguishes different offers. This article focuses on what the terms mean.
How mybody® uses these terms in DNA testing
In practice, genetic analysis means exactly what the hierarchy of terms suggests: DNA is extracted from a sample, the alleles present at defined loci are identified, and these genotypes are interpreted. mybody® (MYBODY Lab GmbH) offers the NutriCare INFINITY DNA Test for this purpose. | INFINITY DNA Test.
NutriCare | INFINITY DNA Test
Using a saliva sample, the test examines over 140 genetic variations and summarizes them in 54 reports across eight chapters, spanning around 200 pages—supplemented by a personalized nutrition plan with recipes and over 1,000 rated foods. Intended as guidance, not a diagnosis.
Price: €269.00 · Sample type: Saliva sample (at home) · Processing time: approx. 20–25 working days · Laboratory: ISO 27001-certified analysis
NutriCare | View INFINITYImportant: The test examines individual, preselected variants—not the entire genome or complete genes. See the DNA Metabolism Tests collection for other analyses. The next chapter explains the limitations of this kind of test—and they are considerable.
Details on price, sample type, processing time, and scope are from the mybody® product page (as of July 2026) and may change.
Putting it in perspective: What a gene variant does—and doesn't—tell you
A genetic analysis shows which alleles are present at the sites examined and which associations research has described. It is a snapshot—and, taken honestly, no more than that.
Gene variants represent probabilities at the group level, not diagnoses or individual predictions. A finding describes how often a trait was observed in people with this variant—not what will happen to a specific person. Between genotype and phenotype lie penetrance, expressivity, other genes, epigenetics, age, diet, and life circumstances.
The evidence is particularly clear for genotype-matched diets. The DIETFITS study followed 609 adults with overweight for twelve months on either a low-fat or low-carbohydrate diet, and also examined whether a genetic pattern predicted success.
According to Gardner et al. (JAMA, 2018), average weight loss after twelve months was 5.3 kilograms in the low-fat group and 6.0 kilograms in the low-carbohydrate group; there was no significant interaction between diet type and genotype pattern. A SNP result therefore says nothing about an individual's weight-loss success.
A DNA test is therefore an information service, not a control tool - and it is no substitute for diagnosis. For symptoms such as persistent fatigue, unexplained weight changes, or digestive problems, the first step is to consult a doctor. Suspected lactose or gluten intolerance should also be medically assessed.
Conclusion
The difference between DNA and genes is easy to state, but has important implications: DNA is the molecule; a gene is a functional section of it. Everything that makes people genetically different happens at the level below - among the alleles and the individual bases that have been swapped.
This ladder of terms helps put statements into context: base, DNA, gene, chromosome, genome are five zoom levels of the same material. About three billion bases, around 19,900 protein-coding genes, and roughly one percent coding DNA (National Library of Medicine, 2021 and 2024) help make the proportions tangible.
And for practical purposes, the most important point remains: a gene variant describes a probability within a group, not a fixed outcome for an individual. Keeping the terms distinct makes it easier to recognize exaggerated claims - and to interpret a test result realistically.
Frequently asked questions (FAQ)
Understand your genetic predispositions
The NutriCare | The INFINITY DNA test analyzes over 140 gene variations in 54 reports from a saliva sample. Intended as a guide – not a diagnosis or a prediction of success.
NutriCare | View INFINITY All DNA metabolism testsYou might also be interested in
→ What does a DNA metabolism test do?
What an analysis evaluates – and how reliable it is.
→ DNA weight loss analysis: cost
What makes up the price.
→ DNA metabolism test: lose weight healthily
How the analysis works.
Sources
- National Human Genome Research Institute (NHGRI), National Institutes of Health: Talking Glossary of Genomic and Genetic Terms, entry “Gene". genome.gov
- MedlinePlus Genetics, U.S. National Library of Medicine (2021): “What is DNA?" medlineplus.gov
- MedlinePlus Genetics, U.S. National Library of Medicine (2024): “What is a gene?" medlineplus.gov
- MedlinePlus Genetics, U.S. National Library of Medicine (2021): “What is noncoding DNA?" medlineplus.gov
- MedlinePlus Genetics, U.S. National Library of Medicine (2021): “How many chromosomes do people have?" medlineplus.gov
- MedlinePlus Genetics, U.S. National Library of Medicine (2022): “What are single nucleotide polymorphisms (SNPs)?" medlineplus.gov
- MedlinePlus Genetics, U.S. National Library of Medicine (2021): “What is the epigenome?”, (2021) “What are complex or multifactorial disorders?” and (2023) “LCT gene”. Epigenome · Complex traits · LCT gene
- Yengo, L. et al. (2022): “A saturated map of common genetic variants associated with human height”, Nature 610:704–712. nature.com
- Gardner, C. D. et al. (2018): “Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern or Insulin Secretion” (DIETFITS), JAMA 319(7):667–679. jamanetwork.com
Gene definition [1] and [3], DNA structure [2], non-coding DNA [4], chromosome number [5], alleles and SNPs [6], epigenetics, complex traits and LCT [7], height [8], genotype-tailored diets [9]. All sources were reviewed on July 28, 2026; the quotation in Chapter 2 is in the original English, with the German version below being an editorial translation. Product information is from mybody-x.com and may change.
mybody® Editorial & Expert Team
This article was created by the mybody® editorial and expert team, which brings together expertise in laboratory diagnostics, genetics, nutritional science, and nutrigenetics. Learn more about us on the editorial and authors page.
Published on July 28, 2026 · Last updated on July 28, 2026
Medical disclaimer: This article is for general information purposes and is not a substitute for medical advice, diagnosis, or treatment. If your symptoms persist, please consult a doctor.
