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108

genome

OLogy Series
biology
card
108

genome

OLogy Series
biology

All the DNA in a cell is called a genome. Your body contains trillions of copies of the human genome -- one in each of your trillions of cells. A genome contains all the genes that tell the cells how to grow. In fact, all animals, plants, viruses, and bacteria have a genome. However, the genomes' sizes and structures vary among different living creatures.

Unraveling the Mystery Behind the Human Genome
In June 2000, scientists working on the Human Genome Project made an announcement that changed history forever. They mapped the first rough draft of the human genome. Who are the mysterious people behind the Human Genome Project and what did they discover? Thousands of scientists in labs all over the United States and in 18 other countries are working together to determine the order of the base pairs in the entire human genome. We now know that humans have over 30,000 genes with over 3 billion base pairs! That's a lot of As, Ts, Gs, and Cs! But what's all this hard work for, anyway? The more we know about our DNA, the more we'll know about how our bodies, cells, and diseases work. DNA research can also help scientists learn more about the similarities between living things and how they change throughout time. The work isn't over yet. Scientists expect to finish their work by 2003. So stay tuned for more genome news. . .

Which animal's genome contains the most "DNA letters"? (A, T, C, G)

fruit fly

human

salamander

Are you right?

Correct!

The size of an animal or plant has nothing to do with the number of parts of its genome. A salamander's genome has about 50 billion "DNA letters." Humans, on the other hand, have about 3 billion of these letters.

The difference between your genes and Albert Einstein's genes is:

yours are baggier

no difference at all

about 3 million different letters of DNA code

Are you right?

Correct!

Considering that we all have about 3 billion letters of DNA code in our genomes, 3 million different letters are not so many. In fact, all humans are 99.9 percent genetically the same -- you do the math!

More than 95 percent of our genome is made of "junk DNA" that scientists once thought was useless.

Fact
or
Fiction
?

Fact

Now they realize that these mysterious, repeating letter patterns may play an important role. Stay tuned. . .

All mammals have the same genome.

Fact
or
Fiction
?

Fiction

Every animal, including you, has a unique genome. Your genome is almost the same as your best friend's, but different from your dog's genome.

genome (GEE-nome)
What: name for all the DNA in a cell
Contains: bases A, T, C, G
Size: about 3 billion bits of information long; contains around 30,000 genes
Characteristics: made of the DNA found in all our
cells
Why important: gives scientists the tools to begin understanding how diseases work and how to prevent them

Image credits: Kelvin Chan.