How much DNA? Wheat 14.5 billion base pairs Yeast 0.01 billion base pairs Lettuce 3.2 billion base pairs Tomato 0.8 billion base pairs Onion 17.5 billion base pairs Pig 3 billion base pairs Cow 2.6 billion base pairs DNA is the genetic code that contains all the instructions our bodies need to grow. But how much DNA is in a person? What about in other animals, or plants? You might think that more complex organisms, like us, need more DNA than simpler species, like plants, but that’s not always the case. DNA is made up of long sequences of paired molecules, known as base pairs. The graphic below shows how many base pairs make up the genomes of each ingredient in a delicious burger. Each line represents 1 billion base pairs. The Onion Test Why does an onion need a genome 6 times longer than a cow? Only a fraction of the genome is actual genes – sections that directly code for proteins – and this size imbalance has been said to illustrate that much of the rest of the sequence must be unused junk. Whatever function this ‘non-coding’ DNA might have, why would an onion need so much more than a human or a cow? This mismatch between an organism’s apparent complexity and its genome size is known to geneticists as the ‘C-value paradox’. The marbled lungfish has the largest known genome of any vertebrate: 129.9 billion base pairs The giant palm salamander has a giant genome: 58 billion base pairs The pufferfish has the smallest known vertebrate genome: 0.3 billion base pairs Birds tend to have smaller genomes than mammals. Turkey: 0.9 billion base pairs Most mammal genomes are 2-4 billion base pairs long (alpaca, cat, gorilla, human and mouse shown here) The human genome is 3.3 billion base pairs long, 5 times smaller than an onion 10,000 20b base pairs 5b 10b 40b 20,000 coding genes Total length of DNA doesn’t necessarily correlate with the number of actual genes. The small pufferfish genome contains a similar number of genes to a cat’s larger genome. Data: grch37.ensembl.org; plants.ensembl.org; cvalues.science.kew.org; genomesize.com;

How much DNA?Onion 17.5 billion base pairs Pig 3 billion base pairs Cow 2.6 billion base pairs DNA is the genetic code that contains all the instructions our bodies need to grow. But

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How much DNA?

Wheat 14.5 billion base pairs

Yeast 0.01 billion base pairs

Lettuce 3.2 billion base pairs

Tomato 0.8 billion base pairs

Onion 17.5 billion base pairs

Pig 3 billion base pairs

Cow 2.6 billion base pairs

DNA is the genetic code that contains all the instructions ourbodies need to grow. But how much DNA is in a person? Whatabout in other animals, or plants? You might think that morecomplex organisms, like us, need more DNA than simplerspecies, like plants, but that’s not always the case.

DNA is made up of long sequences of paired molecules, known as base pairs. The graphic below shows how many base pairs make up the genomes of each ingredient in a delicious burger. Each line represents 1 billion base pairs.

The Onion TestWhy does an onion need a genome 6 times longer than a cow? Only a fraction of the genome is actual genes – sections that directly code for proteins – and this size imbalance has been said to illustrate that much of the rest of the sequence must be unused junk. Whatever function this ‘non-coding’ DNA might have, why would an onion need so much more than a human or a cow? This mismatch between an organism’s apparent complexity and its genome size is known to geneticists as the ‘C-value paradox’.

The marbled lungfish has the largest known genome of any vertebrate: 129.9 billion base pairs

The giant palm salamander has a giant genome: 58 billion base pairs

The pufferfish has the smallest known vertebrate genome: 0.3 billion base pairs

Birds tend to have smaller genomes than mammals. Turkey: 0.9 billion base pairs

Most mammal genomes are 2-4 billion base pairs long (alpaca, cat, gorilla, human and mouse shown here)

The human genome is 3.3 billion base pairs long, 5 times smaller than an onion

10,000

20b base pairs5b 10b 40b

20,000 coding genes

Total length of DNA doesn’t necessarily correlate with the number of actual genes. The small pufferfish genome contains a similar number of genes to a cat’s larger genome.

Data: grch37.ensembl.org; plants.ensembl.org; cvalues.science.kew.org; genomesize.com;