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2 corrections found
Every cell in your body stores each base pair of your 3GB DNA
This is too absolute: mature red blood cells do not contain the nuclear genome because they lack a nucleus.
Full reasoning
The claim says every cell in the body stores the full genome. That is not correct. In humans, mature red blood cells are a standard exception: they lose their nucleus during maturation and therefore do not retain the nuclear DNA.
A National Center for Biotechnology Information (NCBI) Bookshelf chapter on the human genome states that each of the body's cells has its own copy or copies of the genome, "the only exceptions being those few cell types, such as red blood cells, that lack a nucleus in their fully differentiated state."
So while most human cells do contain the genome, the statement as written is factually incorrect because it uses an absolute (“every cell”) that excludes well-known exceptions.
1 source
- The Human Genome - Genomes - NCBI Bookshelf
Each of the approximately 10^13 cells in the adult human body has its own copy or copies of the genome, the only exceptions being those few cell types, such as red blood cells, that lack a nucleus in their fully differentiated state.
only 10 to 20 percent of the protein coding regions are expressed in any particular cell
This substantially understates how many genes human cells typically express. Standard references put expression far above 10–20% of protein-coding genes.
Full reasoning
If this sentence is read in the ordinary way—as a claim about how many protein-coding genes are expressed in a typical human cell—it is far too low.
A standard NCBI Bookshelf cell-biology text says that a typical human cell expresses about 10,000–20,000 of its ~30,000 genes at a given time. Even using that older ~30,000-gene total, that is roughly 33% to 67%, not 10% to 20%.
Likewise, a tissue transcriptome study found that most human tissues express 11,000–13,000 genes, corresponding to roughly 60%–70% of RefSeq protein-coding genes.
So the post's number is off by a large margin. The wording says “protein coding regions,” but in context it is clearly making a point about which genes are active in a cell. On that standard interpretation, the 10–20% figure is not correct.
2 sources
- An Overview of Gene Control - Molecular Biology of the Cell - NCBI Bookshelf
Studies of the number of different mRNAs suggest that, at any one time, a typical human cell expresses approximately 10,000-20,000 of its approximately 30,000 genes.
- An Abundance of Ubiquitously Expressed Genes Revealed by Tissue Transcriptome Sequence Data
Applying the threshold 0.3 RPKM, the number of genes expressed in most human and mouse tissues varied from 11,000 to 13,000, corresponding to roughly 60–70% of RefSeq protein-coding genes.