The DNA in a single human cell stretches about 6 feet when fully uncoiled â and if you unraveled all the DNA in your body, it would stretch from Earth to the Sun and back roughly 600 times. Despite that staggering scale, only about 1.5% of your genome directly codes for proteins. This quiz dives deep into the science of heredity, gene editing, and the genomic revolution reshaping medicine.
Each round presents 10 randomized multiple-choice questions drawn from a pool of 50, so every playthrough is different. You get instant feedback with explanations after each answer, plus a shareable score at the end.
You'll explore the discovery of DNA's double helix structure, how CRISPR-Cas9 works and its first approved treatments, the surprising percentage of DNA humans share with bananas and chimps, genetic testing companies and their limitations, epigenetics and transgenerational inheritance, the genetics of common diseases, and bizarre facts like octopuses editing their own RNA.
CRISPR-Cas9 is a gene-editing system that uses a guide RNA to direct the Cas9 protein (a molecular scissor) to a precise location in the genome, where it cuts the DNA. The cell's repair mechanism then either disables the gene or allows a new DNA sequence to be inserted. Jennifer Doudna and Emmanuelle Charpentier won the 2020 Nobel Prize in Chemistry for developing it. The first CRISPR-based therapy, for sickle cell disease, was FDA-approved in 2023.
DNA ancestry tests are reasonably accurate for identifying broad continental ancestry but much less precise for specific ethnic breakdowns. They work by comparing your SNPs (single nucleotide polymorphisms) to reference populations, which vary significantly between companies. Results for specific percentages like "12% Italian" are statistical estimates, not precise measurements, and can change as reference databases expand.
Yes â humans share approximately 60% of their DNA with bananas. This sounds shocking, but it reflects the deep evolutionary conservation of genes involved in basic cellular functions like metabolism, cell division, and DNA replication, which all eukaryotic life shares. We share 85% with mice, 98.7% with chimpanzees, and 99.9% with other humans.
Last updated: March 2026