What percent of human DNA (genome) codes for human proteins: 1.5% 5.0% 26% 3.5% 12%
The Correct Answer and Explanation is:
The correct answer is 1.5%.
Humans have about 20,000-25,000 protein-coding genes in their genome. However, the vast majority of our DNA does not directly code for proteins. Only a small portion—around 1.5%—is responsible for encoding the proteins that carry out various functions in the body. These protein-coding regions are found within the exons of genes, which are the parts of DNA that are transcribed into mRNA and then translated into proteins.
The rest of our DNA, which makes up about 98.5% of the genome, was once considered “junk DNA,” with no clear purpose. However, recent research has shown that much of this non-coding DNA has important functions. It plays crucial roles in regulating gene expression, maintaining chromosome structure, and influencing the activity of protein-coding genes. For instance, introns, the non-coding regions within genes, are involved in processes like RNA splicing, and promoter regions are vital for initiating gene transcription.
Moreover, regulatory elements found in the non-coding DNA help control when and where certain genes are turned on or off, ensuring proper development and cellular functions. These elements may also contribute to variations in traits among individuals, which may explain why two people with nearly identical protein-coding genes can still have different physical or biological characteristics.
So while only 1.5% of our genome codes for proteins, the remaining DNA is far from useless. It plays a central role in regulating the activities of those proteins and maintaining the overall function of the organism. Understanding the roles of both coding and non-coding DNA is crucial for advancing fields like genomics, medicine, and evolutionary biology.
