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Origin of DNA
Words nearby DNA
What is DNA?
DNA is in every cell of every living thing. Some viruses also have DNA.
Life as we know it wouldn’t exist without DNA—it contains the instructions that cells need to function. DNA is found in the cell nucleus, and every cell in an organism has the exact same copy of DNA that is in every other cell. Each cell uses its copy of DNA whenever it needs to make a protein. Proteins have many essential jobs within a living thing. For example, your immune system produces proteins called antibodies to fight germs.
The information that’s in DNA controls the development of specific traits, such as the shape of a leaf or the color of hair. Specifically, such traits are determined by genes, which are segments of DNA within strands called chromosomes. The set of all information contained in the DNA of any living thing—all of its inheritable traits—is called its genome.
DNA is an abbreviation of deoxyribonucleic acid. It is a type of macromolecule (a very large molecule—one composed of hundreds of thousands of atoms) known as a nucleic acid. Nucleic acids are made of smaller molecules known as nucleotides, which are made of a phosphate, a sugar, and nitrogen bases. The four nitrogen bases in DNA are adenine (A), thymine (T), guanine (G), and cytosine (C).
DNA has a shape known as a double helix, which resembles a spiraled ladder. The DNA ladder is built from two very long strands of nucleotides with the nitrogen bases pairing together to form the rungs of the ladder. The bases form base pairs, with adenine always paired to thymine and guanine always paired to cytosine. The phosphate and sugar within the nucleotide act as the sides of the ladder.
Because DNA only exists within the cell’s nucleus, the genetic information must be distributed somehow. This is one of the roles of RNA, which is a macromolecule that works alongside DNA to make proteins. During this process, RNA acts as a kind of copy of the DNA that carries its genetic information outside of the cell nucleus.
Why is DNA important?
DNA is ancient, but its discovery was relatively recent. In 1869, chemist Friedrich Miescher documented a kind of molecule that had never been studied before—nucleic acid. It wasn’t until around the 1930s that the term DNA began to be used. In the 1950s, the work of biophysicist Rosalind Franklin and biologists James Watson and Francis Crick revealed DNA’s double helix structure.
Cells cannot make proteins without DNA. DNA acts as a set of instructions for any protein that needs to be made.
The study of DNA is central to the field of science known as genetics. DNA contains genetic information that is passed down from one generation to another. You get roughly half of your DNA from your mother and half from your father. This is the reason children look similar but not identical to their parents.
Despite the vast range of different physical traits that people can have, the DNA of all humans is more than 99% identical. Human DNA is made of billions of nitrogen bases, and even minor differences can result in two people that look very different. (Identical twins are born with the exact same DNA.)
The order of nitrogen base pairs is what makes every person and every living thing unique. For example, minor differences in this sequence determine whether a person will have brown eyes or blue eyes.
Did you know ... ?
DNA is analyzed in the study of human evolution. Our closest living biological relatives are chimpanzees and bonobos, whose DNA is over 98% identical to ours. This fact has contributed to the theory that humans and chimpanzees share a common ancestor that lived millions of years ago.
What are real-life examples of DNA?
This illustration shows a simplified rendition of DNA’s double helix structure.
DNA is crucial to life, and learning about DNA is a crucial part of the study of biology.
A Change in One Gene Might've Made Our Brains Uniquely Human | "It's fascinating to see that a single base-pair alteration in human DNA can change how the brain is wired," said Prof Alysson R. Muotri, PhD. https://t.co/vIuJwTb0d0 pic.twitter.com/96Fy4IKAwh
— LabRoots (@LabRoots) February 16, 2021
Can the mRNA COVID-19 vaccines alter your DNA? The answer is NO. Discover why here, and learn more about other frequently asked questions by visiting https://t.co/BPTUBoss1t pic.twitter.com/rOXtQ3SX4Q
— COVID-19 Prevention Network (@PreventCOVID_19) February 17, 2021
What other words are related to DNA?
True or False?
DNA is essential to life because it contains instructions for the production of proteins.
Example sentences from the Web for DNA
Using standard methods, the cost of printing DNA could run upwards of a billion dollars or more, depending on the strand.
Through his company, consumers will be able to cheaply make custom DNA strands, including what Heinz calls “creatures.”
DNA tests were used to confirm Albert's status as father in both cases, following protracted legal battles.Princess Charlene Gives Birth To Twins Gabriella and Jacques|Tom Sykes|December 10, 2014|DAILY BEAST
The at-home genetics testing company 23andme, established in 2006, helps people learn more about their “DNA relatives.”
The story (and some DNA evidence) goes, the locals are the descendants of a band of Roman soldiers from 36 B.C.
The Dna takes a westerly course towards the Gulf of Riga where it empties near the city of that name.
Another bishop sailed up the Dna with a fleet of twenty-three ships, and in 1200 founded Riga.
This is a pitiful admission for a biochemist to make—DNA should be the cornerstone of his life.Card Trick|Walter Bupp AKA Randall Garrett
The cup and foot are of agate, probably specimens of the classic period; the mounting, which dates from the time of Dna.The Industrial Arts in Spain|Juan F. Riao
Ruoy xis snisuoc emac ereh yadretsey, dna dah hcae a eceip fo ekac.The Letters of Jane Austen|Jane Austen
British Dictionary definitions for DNA
Medical definitions for DNA
Scientific definitions for DNA
Cultural definitions for DNA
The molecule that carries genetic information in all living systems (see genetic code). The DNA molecule is formed in the shape of a double helix from a great number of smaller molecules (see nucleotides). The workings of the DNA molecule provide the most fundamental explanation of the laws of genetics.
DNA acts in three important way. First, when a cell divides, the DNA uncoils, and each strand creates a new partner from the surrounding material — a process called replication. The two cells that result from the cell division have the same DNA as the original (see mitosis). Second, in sexual reproduction, each parent contributes one of the two strands in the DNA of the offspring. Third, inside the cell, the DNA governs the production of proteins and other molecules essential to cell function.