Human Growth and Development / Unit 2 HGD 0156 short lesson, about 20 seconds
Genes and the Genome
Captions available
The idea
A gene is a segment of DNA carrying instructions for making proteins; humans have about twenty thousand to twenty-five thousand genes.
In practice
The genome, the full DNA sequence, written in four bases: guanine, adenine, thymine and cytosine.
Where people slip
People share about ninety-nine point nine percent of the genome; the remaining tenth of a percent carries individual differences.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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