6 Key Differences Between DNA and Genes

To grasp the fundamental concepts of genetics, it’s essential to understand the distinctions between DNA and genes. 

DNA (Deoxyribonucleic Acid)

Definition- DNA is a long, double-stranded biomolecule composed of nucleotides. Each nucleotide contains a sugar molecule, a phosphate group, and a nitrogen base.

Structure- The structure of DNA resembles a twisted ladder, known as a double helix.

Location- DNA is primarily located within the nucleus of a cell.

Function-

• Genetic Blueprint- DNA holds the genetic instructions necessary for the development and functioning of living organisms.
• Replication and Transmission- DNA replicates itself during cell division, ensuring genetic information is passed from one cell to another and from parents to offspring.
• Mutation and Regulation- DNA undergoes mutations, which can lead to genetic variation, and plays a critical role in regulating gene expression.

Gene

Definition- A gene is a specific sequence or segment of DNA that encodes for a particular protein or RNA molecule.

Structure- Genes are shorter sections of DNA, located on chromosomes.

Function-

• Protein Coding- Genes direct the production of proteins, which perform most of the critical functions in the body.
• Heredity Units- Genes are the basic units of heredity, passed from parents to their children.
• Regulatory Roles- Genes help regulate the functions of both DNA and RNA within the cell.

6 Important Differences Between DNA and Genes in tabular Format 

Table summarising the key differences between DNA and genes-

Aspect	DNA (Deoxyribonucleic Acid)	Gene
Definition	A molecule consisting of two long strands of nucleotides twisted into a double helix.	A segment of DNA that codes for a protein or RNA molecule.
Composition	Made up of long chains of nucleotides, each containing a sugar, phosphate group, and a nitrogen base.	A specific sequence of nucleotides within the DNA.
Structure	Double helix.	Located on a section of the DNA strand, generally organised in chromosomes.
Location	Primarily in the nucleus of cells.	On chromosomes within the DNA structure in the nucleus.
Function	Stores and transmits genetic information, ensures replication, undergoes mutations, and regulates gene expression.	Directs the production of proteins, serves as units of heredity, and regulates functions of DNA and RNA.
Role in Genetics	Contains the complete genetic blueprint of an organism.	Acts as instructions for building specific proteins that influence traits and functions.

Key Differences Between DNA and Genes Explained in Details

1. Definition

• DNA (Deoxyribonucleic Acid)- DNA is composed of two long strands of nucleotides that twist around each other to form a structure known as the double helix. It serves as the genetic material in most living organisms and some viruses, encoding the information necessary for life processes.
• Gene- A gene is a specific segment or sequence of DNA that is responsible for coding for a protein or an RNA molecule. Each gene occupies a specific position on a chromosome and plays a role in determining the physical and functional traits of an organism.

2. Composition

• DNA- DNA is made from nucleotides, each consisting of three components- a sugar molecule (deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). The order of these bases along the DNA strand dictates the genetic instructions used in the development and functioning of organisms.
• Gene- Genes are composed of specific sequences of these nucleotides within the DNA. The exact sequence of nucleotides in a gene determines the structure and function of the proteins produced.

Also Check – 6 Important Differences Between DNA and Chromosomes

3. Structure

• DNA- The structure of DNA is famously known as the double helix, described as a twisted ladder. The sides of the ladder are formed by the sugar and phosphate backbone of each strand, while the rungs consist of paired nitrogenous bases (A pairs with T, and C pairs with G).
• Gene- Structurally, a gene is not a separate physical entity from DNA but a designated segment within the broader DNA molecule. Genes are typically organised into specific locations on chromosomes, which are long strands of DNA coiled around structural proteins.

4. Location

• DNA- DNA is primarily located in the nucleus of a cell, but small amounts can also be found in organelles such as mitochondria and chloroplasts (in plants).
• Gene- While also primarily located in the nucleus as part of the DNA, genes are specifically found on chromosomes. Each chromosome contains many genes.

Also Check – Genetic Signatures of a Defective Heart

5. Function

• DNA- The overarching function of DNA is to store and transmit genetic information across generations. It’s involved in critical biological processes such as replication (copying itself), mutation (undergoing changes), and gene regulation (controlling which genes are turned on or off).
• Gene- The primary function of a gene is to direct the production of proteins or RNA molecules, which are crucial for the various biochemical processes within an organism. Genes also play a vital role in heredity, as they are the units that carry genetic information from parents to offspring.

Also Check – 8 Key Differences Between Plasmid DNA and Chromosomal DNA

6. Role in Genetics

• DNA- DNA contains the complete genetic blueprint of an organism. It holds all the information required to build and maintain that organism, encoded in the sequence of its nucleotides.
• Gene- Genes act as specific instructions within the broader DNA sequence. Each gene influences particular traits or functions by directing the production of a protein or RNA, which has a direct effect on the organism’s phenotype and physiological functions.

Points to Remember for Exam Preparation

• DNA is the molecule that contains the genetic instructions used in growth, development, functioning, and reproduction.
• Genes are segments of DNA that are instructions for making molecules called proteins.
• DNA is structured as a double helix; genes are sections of this structure.
• Both DNA and genes are essential for hereditary information transmission, but a gene is a functional unit within the DNA sequence.

Also Check – Also Check – 4 Important Differences Between Genes and Chromosomes

FAQs on Differences Between DNA and Genes 

What is DNA?

• Answer- DNA (Deoxyribonucleic Acid) is a biomolecule made of two long, twisted strands of nucleotides forming a double helix structure. It contains the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses.

Also Check – Why is DNA copying an essential part of the process of Reproduction?

What is a gene?

• Answer- A gene is a specific segment of DNA that codes for a protein or RNA molecule, serving as units of heredity and playing a crucial role in determining the traits of organisms.

Describe the structure of DNA.

• Answer- The structure of DNA resembles a twisted ladder or double helix, where the sides of the ladder are made of alternating sugar and phosphate groups, and the rungs consist of paired nitrogenous bases (adenine with thymine and guanine with cytosine).

How does a gene differ structurally and functionally from DNA?

• Answer- Structurally, a gene is a shorter segment of DNA located on a chromosome. Functionally, while DNA stores and transmits genetic information for the whole organism, a gene specifically directs the production of proteins and regulates specific traits and functions.

Where is DNA located within a cell?

• Answer- DNA is primarily located in the nucleus of a cell, though some can also be found in organelles like mitochondria and chloroplasts (in plants).

What role do genes play in heredity?

• Answer– Genes are the basic units of heredity passed from parents to offspring. They determine specific traits by directing the synthesis of proteins that manifest these traits.

Explain how DNA and genes are related.

• Answer- DNA acts as the repository of genetic information, whereas genes are parts of this DNA tasked with specific functions like protein synthesis. Genes represent functional segments of the larger DNA molecule.

What is the significance of the location of genes on chromosomes?

• Answer- The location of genes on chromosomes is crucial for the regulation of gene expression and for ensuring that genetic information is accurately replicated and distributed during cell division.

How do mutations affect DNA and genes?

• Answer- Mutations alter the nucleotide sequences of DNA, which can affect genes by changing the proteins they encode. This can lead to various genetic disorders or may contribute to evolutionary changes.

What is the role of DNA in the replication process?

• Answer- DNA replicates itself before cell division, ensuring that each new cell receives a complete set of genetic instructions. This replication process involves unwinding the double helix and using each strand as a template to synthesise a new complementary strand.