We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What are Base Pairs?

Mary McMahon
Updated May 21, 2024
Our promise to you
All The Science is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At All The Science, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Base pairs are pairs of nucleotides joined with a hydrogen bond found in DNA and RNA. This genetic material is typically double-stranded, with a structure which resembles a ladder, and each set of base pairs making up a single rung of the ladder. Base pairs have a number of interesting properties which make them topics of interest, and understanding how base pairs work is important to many geneticists.

The nucleotides which make up DNA are adenine (A), thymine (T), cytosine (C), and guanine (G). In RNA, the thymine is replaced with uracil (U). Together, these small chemical compounds make up the genetic code of an organism, with their arrangement coding for the production of a number of proteins. Adenine can only bond with thymine, and cystosine can only bond with guanine. This means, for example, that when a strand of DNA is examined, if there's a A on one end of a rung, a T must be on the other.

Adenine and guanine are both types of molecules known as purines, while thymine and cytosine are pyrimidines. Purines are larger, with a structure which prohibits two of them from fitting on one rung of the ladder, while pyrimidines are too small. This means that adenine cannot become a base pair with guanine, and thymine cannot be in a base pair with cytosine.

One might reasonably ask why the purine adenine couldn't bond with the pyrimidine cytosine, and why thymine cannot bond with guanine. The answer has to do with the molecular structure of these compounds; adenine cannot form a hydrogen bond with cytosine, just as thymine cannot form a hydrogen bond with guanine. These properties dictate the fundamental arrangement of base pairs, with the compound on one end of the rung dictating which compound will lie on the other side.

It takes numerous sets of base pairs to make up a single gene, and any given strand of DNA can contain numerous genes in addition to sections of what is known as “non-coding DNA,” DNA which does not appear to have any function. The human genome contains an estimated three billion base pairs, which explains why it took so long to successfully sequence the human genome, and understanding the arrangement of base pairs doesn't help people understand where specific genes lie, and what those genes do. In a way, base pairs could be considered the alphabet which is used to write the book of the genetic code.

All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Link to Sources
Mary McMahon
By Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a All The Science researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments
By anicole — On Apr 23, 2013

So how does base pairing work in DNA?

By anon247732 — On Feb 14, 2012

What are the number of base pairs and the sequence of gene IGF2 for homo sapiens?

By UNKing — On Jun 01, 2011

This non-coding DNA (formerly "junk DNA") still has base pairs though, true? It doesn't code for proteins but it's part of the instructions to turn DNA off or on to control whether or not the gene is expressed.

Studies are showing that variations in the DNA interval (how long the base pair strand is) on a certain chromosome increases risk of coronary artery disease.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a...

Learn more
All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.