50 Fun Facts About DNA Trivia for Kids

DNA is shaped like a twisted ladder, a form known by what name?

A double helix. Its two strands can unzip down the middle, and each half then serves as the pattern for rebuilding its partner, which is how a cell copies its DNA.

DNA comparisons show which ape is, alongside the bonobo, the closest living relative of humans?

Chimpanzee. That does not mean people evolved from chimps: the two lines branched from a shared ancestor millions of years ago, and each has kept changing ever since.

In DNA, the letter A always pairs with which letter?

T, short for thymine. Cells proof-read these pairings as they copy DNA: when the wrong letter slips in opposite an A, repair proteins spot the mismatch and swap in the right one.

What do the letters DNA stand for?

Deoxyribonucleic acid. For decades scientists thought it a dull structural chemical and expected proteins to carry inherited traits, until experiments in the 1940s pointed to DNA instead.

The two side rails of the DNA ladder are built from phosphate and which other ingredient?

Sugar. DNA's sugar has one oxygen atom fewer than the sugar in its cousin RNA, and that small gap makes DNA the sturdier of the two, fit to store instructions for a lifetime.

Inside animal and plant cells, where is most DNA stored?

In the nucleus. Your mature red blood cells are the exception: they lose their nucleus as they develop, leaving a flexible cell that can squeeze through the narrowest blood vessels.

How many chromosomes does a typical human body cell contain?

46. Half come from each parent: an egg and a sperm carry just 23 apiece, so joining them restores the full set instead of doubling it with every generation.

Which pair of sex chromosomes do boys usually have?

An X and a Y. Every egg carries an X, so it is the sperm, bringing either an X or a Y, that settles whether a baby is a boy or a girl.

An extra copy of chromosome 21 in a person's cells causes which condition?

Down syndrome, also called trisomy 21. The extra copy usually appears by chance when an egg or sperm cell forms, and is not caused by anything the parents did.

Which cell part reads instructions copied from DNA and builds proteins?

The ribosome. Bacteria have ribosomes too, but built a little differently, and many antibiotics work by jamming theirs while leaving ours alone.

Which special proteins act like spools that DNA winds around to fit inside a cell?

Histones. They do more than save space: by loosening or tightening their grip on the DNA, they help decide which genes a cell can read and which stay switched off.

Friedrich Miescher first isolated DNA in 1869 from cells in what, washed off used hospital bandages?

Pus. It is packed with white blood cells, and a nearby surgical clinic could send him bandages soaked in it, so Miescher had a steady supply of cells for his experiments.

Which two scientists announced the twisted-ladder structure of DNA in 1953?

Watson and Crick. They worked it out by shuffling cardboard cutouts of DNA's parts around a desk like puzzle pieces, guided by measurements other scientists had made.

In 2001 scientists in Texas produced the world's first cloned pet, which was what kind of animal?

A cat, known as CC. She was a genetic copy of her donor, a calico called Rainbow, yet her coat came out in a different pattern, proof that DNA alone does not fix how an animal looks.

Rosalind Franklin was an expert in which scientific skill?

X-ray crystallography. Her images were key evidence for DNA's shape, but she died of cancer in 1958 aged 37, four years before the discovery won a Nobel Prize she could no longer share.

Which scientist wrongly proposed in early 1953 that DNA had three intertwined strands?

Linus Pauling. His three-strand model rested on basic chemistry mistakes, a slip from the man who won the Nobel Prize in Chemistry the very next year for explaining how atoms bond.

Gregor Mendel worked out the basic rules of heredity by growing which plants?

Peas. They suited the job: each trait came in two clear forms, such as tall or short, and Mendel could pollinate the flowers by hand to control exactly which plants were crossed.

Gregor Mendel, the founder of genetics, had what job?

Monk. His abbey sent Mendel to the University of Vienna to study science, and back home he turned the monastery garden into a laboratory for years of breeding experiments.

Identical twins look alike because they grow from what?

One egg that split in two. Starting from the same fertilised egg gives the pair matching DNA, which is why scientists compare such twins to tease apart the effects of genes and upbringing.

Which type of DNA do you inherit only from your mother?

Mitochondrial DNA. Only the egg's mitochondria survive fertilisation, so this small loop of DNA passes down the female line, letting researchers trace maternal ancestry far back in time.

Roughly how many base pairs (letters) are in the human genome?

3 billion. Yet any two people share about 99.9% of those letters, so everything in the code that makes you different from a stranger sits in roughly one letter in a thousand.

Which US president announced the first rough draft of the human genome?

Bill Clinton, in June 2000, with Britain's Tony Blair joining by satellite. The public project and its private rival, Celera, had been racing each other and shared the stage to announce their drafts together.

National DNA Day, April 25, marks the 1953 day when DNA's structure was published in which journal?

Nature. Congress first declared the day in 2003 to mark two milestones at once: 50 years since the DNA papers and the completion of the Human Genome Project.

Dolly, the first mammal cloned from an adult cell, was what kind of animal?

A sheep. Scientists had believed a specialised adult cell could never be turned back to build a whole body; Dolly's birth in 1996, after hundreds of failed attempts, proved them wrong.

Dolly the clone was grown from a cell taken from which part of her adult donor?

A mammary gland. That milk-making origin inspired her name: the team called her Dolly as a playful nod to the country singer Dolly Parton.

In Jurassic Park, scientists get dinosaur DNA from mosquitoes trapped in what?

Amber. In real life the plan fails: DNA slowly falls apart, and scientists who measured its decay found that none could stay readable for anything like the time since the dinosaurs.

Which 1997 science-fiction film has a title spelled entirely with the letters used to write DNA's code?

Gattaca. Its title uses only G, A, T and C, and its hero, judged unfit by a gene test at birth, borrows another man's blood and urine samples to pass as genetically perfect.

DNA fingerprinting, the technique police now use worldwide, was invented in 1984 in which country?

England. Alec Jeffreys devised it at the University of Leicester, and when police first used it in a murder hunt in 1986, it cleared their main suspect before it caught the real culprit.

Which laboratory trick, invented by Kary Mullis, makes millions of copies of a tiny bit of DNA?

PCR, short for polymerase chain reaction. Each round of heating and cooling doubles the DNA, so about 30 rounds can turn a single fragment into more than a billion copies.

Scientists often compare the gene-editing tool CRISPR to which everyday object?

Scissors. Bacteria invented the trick first: they use CRISPR to recognise invading viruses and snip the viruses' DNA apart, and scientists reprogrammed it to cut any gene they choose.

Which two scientists won the 2020 Nobel Prize in Chemistry for CRISPR gene editing?

Jennifer Doudna and Emmanuelle Charpentier. Their tool reached patients little more than a decade after their key 2012 experiment: in 2023 regulators approved the first CRISPR medicine, a treatment for sickle cell disease.

GloFish, the glowing pet fish, were first made from which small aquarium fish?

Zebrafish. The glow began as serious science: researchers in Singapore gave the fish a jellyfish gene, hoping to breed living alarms that would light up in polluted water.

Svante Paabo won a Nobel Prize in 2022 for reading the DNA of which extinct human relatives?

Neanderthals. Their genome revealed that they had children with our own ancestors, so people of European or Asian descent still carry a small share of Neanderthal DNA today.

In 2021 scientists read million-year-old DNA, then the oldest known, from what animal?

A mammoth. Its teeth had lain frozen in Siberian permafrost, the kind of deep cold that keeps DNA readable longest; in 2022 the record passed to two-million-year-old DNA from Greenland soil.

Which molecule takes a gene's instructions from DNA to the cell's protein-building machinery?

Messenger RNA. Some COVID-19 vaccines borrow the trick: they hand your cells a lab-made message to build one harmless piece of the virus, and the cells break the message down soon afterwards.

Which two scientists won the 2023 Nobel Prize for the discoveries behind COVID-19 mRNA vaccines?

Katalin Kariko and Drew Weissman. Lab-made mRNA used to set off the body's alarm system; in 2005 they showed that altering one of its chemical letters let it slip past, clearing the way for the vaccines.

A change in the DNA sequence, which can happen when a cell copies its DNA wrongly, is called what?

A mutation. Most have no effect at all, but now and then one helps: a change that lets adults keep digesting milk became common among peoples with a long history of dairy farming.

Telomeres are protective caps found where?

The tips of chromosomes. Telomeres get slightly shorter each time a cell divides, and once they wear down too far the cell can no longer divide, a built-in limit linked to ageing.

Bacteria are simpler than our own cells, so where do they keep their DNA?

Loose in the cytoplasm. Bacteria also carry small extra rings of DNA there, called plasmids, and can pass them to their neighbours, which is one way resistance to antibiotics spreads.

When scientists pull pure DNA out of cells in a lab, what does it look like?

White stringy clumps. DNA stays dissolved in water but not in alcohol, so pouring cold alcohol onto the mixture makes the long strands tangle together until they can be lifted out on a stick.

Which fruit, a favourite for kitchen DNA experiments, carries eight sets of chromosomes in each cell?

Strawberry. Humans carry just two sets, but the garden strawberry arose in the 1700s as a cross between two wild species that each carried eight, so it inherited eight as well.

Thomas Hunt Morgan proved that genes sit on chromosomes by studying which tiny creature?

Fruit flies. The breakthrough came from a single male born with white eyes instead of red: by breeding it, Morgan showed that the trait travelled with one particular chromosome.

Barbara McClintock won a Nobel Prize for discovering 'jumping genes' in which crop plant?

Corn. The spots and streaks on multicoloured kernels were her clue: each marks cells where a jumping gene had moved and switched a nearby colour gene off or on.

Most three-letter 'words' in the genetic code tell a cell to add which kind of building block?

Amino acids, the units proteins are built from. Three letters make 64 possible words for just 20 amino acids, so most are spelled several ways, and that slack lets many small changes to DNA pass harmlessly.

DNA from living relatives helped identify the skeleton of which medieval king, found under a car park in 2012?

Richard III. The bones closely matched the DNA of two living relatives descended from his sister through an unbroken line of mothers and daughters, more than 500 years after he died in battle.

In 1978 scientists first coaxed bacteria into making which human medicine by giving them a human gene?

Insulin. Before that, people with diabetes depended on insulin taken from the pancreases of cows and pigs; bacteria carrying the human gene could brew the human version in vats.

Chargaff's rules say the amount of guanine in DNA always equals the amount of which other base?

Cytosine. Chargaff also found that the mix of bases differs from one species to the next, which sank the old idea that DNA was the same dull repeating chain in every living thing.

The 1952 Hershey–Chase experiment, strong evidence that genes are made of DNA, famously used which kitchen appliance?

A blender. Whirling the mixture shook the viruses' empty protein coats off the bacteria they had infected, while the viral DNA stayed inside the cells, pointing to DNA as the carrier of instructions.

Besides DNA, Rosalind Franklin was known in her lifetime for studying viruses and which fuel?

Coal. It was her war work: in 1942 she joined Britain's coal research association, where studying the tiny holes in coal let her serve the war effort and earn a PhD at the same time.

Many DNA tests need no needle, only a swab rubbed gently against which part of the body?

Inside the cheek. Cells there rub off painlessly onto the swab, and because nearly every cell carries a full copy of your DNA, those few are enough for the lab.