What species carries the most DNA in a single cell?
What species has the most DNA in the entire organism?
What species in aggregate by total Earth population, has the most DNA?
By “most”, assume total mass of only the DNA molecules.
The organism with the biggest genome is actually a single-celled organism: [url=“Polychaos dubium - Wikipedia”]Amoeba dubia. 670 billion base pairs, 200 times larger than the human genome.
The organism with the most DNA in the entire organism is likely a plant or a fungus. Many plants have genomes in the 100 billion base pair range and many fungi are massive organisms, stretching across many square miles. It may be difficult to answer your second question definitively.
Your third question is probably even more difficult to answer as we would need an accurate count of the total number of individuals of each species. Then there is the problem of species identification. Those massive fungi I mentioned are notoriously difficult to assign a species to because many species look completely identical until they reproduce.
Wow - those are tricky questions.
Some contenders for the third question might be considered independently of getting accurate counts of individuals from each species - there are some estimates of which species may have the greatest biomass (total mass of all living members of that species).
Take with a grain of salt because it’s Wikipedia, but the wikipedia article on Antarctic krill contains speculation that it may be the species with the greatest biomass, which would put it in contention for the species with the most DNA total:
Other contenders might be some species of ants or benthic amphipods or echinoids (sea urchins and and dollars,) which are also thought to have very high biomasses.
Yes, according to this record holder.
That 3rd question is interesting. I think I’d say either a bacteria or a bacteriophage. I wrote a paper 7 years ago where I said “Some fresh water ecosystems contain up to a billion tailed phages per milliliter, and around one million per milliliter in coastal seawater – the global population of tailed phages alone is calculated to be 10^30. Together all the phages in the world would outweigh the world population of elephants by a thousand-fold or more.” The direct reference is now lost but somewhere on this site:Site
So, considering the minimum for phage genomes is about 5000 bp, but up to 500,000 bp, that’s a lot of DNA. Consider also that phages are mostly DNA, with only a protein coat and not all of that other mass that elephants would have. Bacteria can have genomes of 500k or more, but I don’t know if they can achieve the same numbers as phages. 10^30 is a lot, even for a bacteria. To put it in perspective, it would take E. coli, which divides every 20 minutes, 100 divisions to reach this number. That puts them at about 1.4 days of exponential growth, and at 2 days they reach the mass of the earth if I recall correctly.
That is really interesting. What does it need all that DNA for?