DNA, or deoxyribonucleic acid, is the carrier of genetic information for the vast majority of living organisms. The only known exceptions are RNA viruses.
17
votes
2answers
2k views
What is the advantage of circular DNA in bacteria?
From what I understand, bacteria have circular DNA. What advantages does it have over linear strands like for eukaryotes?
Do there exist bacteria with more than one ring of DNA?
10
votes
3answers
446 views
What implications has the missing 2'-OH on the capability of DNA to form 3D structures?
The chemical difference between RNA and DNA is the missing 2'-hydroxyl group in the nucleotides that build DNA. The major effect of that change that I know of is the higher stability of DNA compared ...
20
votes
3answers
273 views
Is telomere length a reliable measure of health/lifespan?
Several companies are commercializing tests for telomere length such as this one here. I understand the basic mechanism for why telomeres shorten during DNA replication, but how good is the evidence ...
8
votes
1answer
160 views
Does DNA react in all of the ways most other acids do?
As I understand it from my basic chemistry, there are some fundamental reactions that exist between any acid and other substances for example acid-base reactions that form a salt, and the existence of ...
8
votes
1answer
529 views
How to DIY preserve pet DNA today so that it can be used in 20 years
I know that there are companies that offer a kit+storage of your pet DNA for around $2k.
My question is if there is any other option for doing this yourself with a thought in mind that in 20+ years ...
6
votes
1answer
422 views
Does extracted DNA degrade after a certain time period?
For direct use as template in PCR runs. Chelex 100 5-10% w/v extraction. Without listing the whole protocol, in the end the supernate is decanted off and then stored at 4°C. I was under the impression ...
29
votes
4answers
1k views
Life without DNA?
I'm by no means an expert in the field, merely a curious visitor, but I've been thinking about this and Google isn't of much help. Do we know of any lifeforms that don't have the conventional ...
4
votes
1answer
75 views
How does “inheritance of methylation” of DNA and/or histones work?
What are the current models/ideas describing the mechanisms explaining inheritance of methylation on DNA resp. histone level?
Is there evidance of this "setup" information being really ...
12
votes
1answer
167 views
What is the prehistory of amino acids in cells?
As a followup to Why 20 amino acids instead of 64? and What is the smallest number of amino acids required for life?, I am trying to understand the prehistory of amino acids in cells.
All living ...
10
votes
1answer
189 views
How do CpG islands remain unmethylated?
In most of the genome CpG sites are pretty much always methylated, but CpG islands are instead often unmethylated. This has been linked to the fact that they often are associated to transcripted ...
22
votes
3answers
2k views
Why do eukaryotic organisms have introns in their DNA?
We touched on introns and exons in my bio class, but unfortunately we didn't really talk about why Eukaryotes have introns. It would seem they would have to have some purpose since prokaryotes do not ...
15
votes
4answers
755 views
Why are there exactly four nucleobases in DNA?
Does someone know why DNA is composed of four nucleobases? In particular, is there an explanation for the number? Why four and not two, or eight?
12
votes
3answers
3k views
How many agarose gel bands are typical for circularised DNA
I am aware that circular DNA can be both relaxed and super coiled. However when running an agarose gel of the circular plasmid along with singly digested plasmid with BamHI and HindIII, I see 1 band ...
11
votes
1answer
423 views
Is there an advantage to linear chromosomes?
The DNA copying enzymes have a hard time working to the end of a chromosome. For circular chromosomes this is not a problem, since there is not a sharp 'end'. However, for a linear chromosome, without ...
11
votes
1answer
180 views
Abiogenesis: Beyond the research journals as a lead in to discussions on evolution
I just came across this abstract:
Aminoacyl-tRNA synthetases (aaRSs) are responsible for creating the pool of correctly charged aminoacyl-tRNAs that are
necessary for the translation of genetic ...
9
votes
3answers
269 views
Source of DNA sequences
I'm working on a project where I am taking DNA sequences and translating the codons into musical notes. I have some good ideas of how to do this, I'm just not sure what sequences to work with. My case ...
8
votes
3answers
203 views
What kind of event would cause the current Mitochondrial Eve to be replaced by a new one?
Apparently all living humans are matrilineal descendants of a single woman who lived 200.000 years ago. She is called Mitochondrial Eve.
But at the time she lived there was a different matrilineal ...
4
votes
1answer
86 views
Can forensic DNA analysis be used to generate a visual approximation of a suspect?
In light of the current US supreme court case, I'm curious if enough information can be teased out of a DNA sample to get a "reasonable" approximation of the suspect (never mind the legality). I ...
2
votes
1answer
72 views
Expanding the SETI initiative to seek intelligent data within DNA sequences?
I've recently read a couple articles dealing with long term data storage, and DNA was suggested as one of the prime candidates for long term storage of digital data additionally, there is this article ...
