Question about DNA/heredity info

[aqua_eyes23]

How can you account for 95 % of the human DNA carrying no apparent functional heredity information? There are about 25,000 genes which dictate proteins structure in the remaining 5%. How can you account for the fact there are roughly 100,000 genetically specified proteins but only 25,000 genes?

Thanks so much for the help

Sara

[biostudent84]

I think you heard a very liberal estimate. It's more like 10% of the DNA we have is used. The rest is termed "junk DNA." The majority of the hypotheses include DNA left over from evolution, and useless genetic material placed into the sequence by viruses. Don't forget that DNA when stretched out is almost 24 miles long. 2.4 miles of DNA can still carry a heck of a lot of information.

[RobJim]

Aqua_eyes23 -

How can you account for 95 % of the human DNA carrying no apparent functional heredity information?

I'm not sure how you want me to "account" for this. Why does this bother you? What needs explaining?

How can you account for the fact there are roughly 100,000 genetically specified proteins but only 25,000 genes?

Some genes make polypeptides which are then cut into multiple proteins by enzymes. This results in several small proteins coming from one long gene.

[canalon]

The rest is termed "junk DNA." The majority of the hypotheses include DNA left over from evolution, and useless genetic material placed into the sequence by viruses. Don't forget that DNA when stretched out is almost 24 miles long. 2.4 miles of DNA can still carry a heck of a lot of information.

Be carefull! The so called "junk DNA" may not be just leftovers and useless as it has been thought. It's just we don't know what it's used for.
Some explanation are suggested, as just being used as spacer between genes, that could be important to explain different transcription level (moving a gene out of a coiled DNA region, or farther from a strong promoter...).
So all this DNA DNA is probably not just junk. Otherwise evolution would have strongly selected against such a heavy load of junks in our genomes.

Patrick