Deoxyribonucleic acid (DNA) is the carrier of genetic information, including for all known living organisms. The only known exceptions are RNA viruses.

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High sequence similarity but start codon isn't methionine

I have noticed in a particular genome sequence of a prokaryote that various regions in a sequence share similarity which is high(>80%) with known proteins. However, the start is not a methionine. Is ...
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1answer
114 views

How much can be said about behaviour (future) based on bloodgroup?

My bloodgroup for example is A+. How much information is knowing my bloodgroup? How much information can be known from a blood sample? I expect you to be able to clone if known a complete DNA sequence ...
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1answer
78 views

Can IVF decrease the probability of trisomy in the fetuses of older mothers?

Is trisomy mostly due to complications with fertilization? If so, does in vitro fertilization reduce the probability of trisomy for the fetuses of older mothers? If not, can zygotes be screened ...
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1answer
661 views

How is instinctual information encoded?

If instincts are passed on through genetics, how is that information encoded in DNA? For example, spiders instinctively know how to spin webs. Does that imply that the algorithm for web spinning is ...
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1answer
2k views

How does a thymidine block halt DNA synthesis?

The best I've been able to find is that there's a feedback mechanism, but what is this feedback, and how does the mechanism work? If it's just that the concentration of thymidine is too high, why ...
4
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1answer
177 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 ...
3
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1answer
399 views

Why re-label the strand ends in 3' DNA labelling?

I have a problem with a molecular biology question; I don’t understand how DNA 3’ labelling works. I took a diagram from my lesson and tried to understand with it; this is what I understood. If I’m ...
5
votes
3answers
164 views

What are the limitations of commercial-grade DNA genotyping compared to full sequencing?

I've heard about services like 23andme, which offer genetic testing to the general public. As a person who knows very little about genetics, I'm interested in the subject and would like to know what ...
6
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1answer
383 views

How does Topoisomerase II inhibition affect cancer cells?

Topoisomerase II poisons represent some of the most important and widely prescribed anticancer drugs currently in clinical use. These drugs encompass a diverse group of natural and synthetic ...
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2answers
41 views

Studying changes in DNA for causes of cancer

First of all let me say that I'm not into Biology myself... but I have a question for those of you who are. From what I've read, cancer is caused by 'faulty' DNA that behaves abnormally. Mutations ...
5
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1answer
1k views

How does formaldehyde cause protein-DNA crosslinking?

How does formaldehyde cause protein-DNA crosslinking? I would guess it's because the strongly polar water molecule interacts strongly with polar residues on a protein-DNA complex, and adding a less ...
5
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2answers
225 views

How to find Exons in mRNA Computationally

I'm having trouble finding a method to find exons in the original DNA sequence used to create the mRNA, even given the sequence of the mRNA, as I cannot find a way to reliably identify the beginning ...
4
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3answers
4k views

Why are 3 nucleotides used as codons for amino-acid mapping in DNA?

DNA is made of 4 unique nucleotides. When coding for a protein, a sequence of 3 nucleotides is used to code for each amino acid. Why are codons 3 nucleotides in length? A related question can be ...
5
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1answer
531 views

What is the fiber axis in the Watson and Crick paper?

I was reading Watson and Crick's article on DNA structure, and the diagram on the lower left of the first page had something called the fiber axis going through the DNA. This axis isn't in modern ...
3
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0answers
78 views

Papers linking telomeres and aging [closed]

I'm currently writing a piece of work about telomeres and aging, and wondered if you could share some good papers you've either read or know of.
2
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3answers
86 views

Simulating Cell differentiation

I'm a computer programmer deeply interested in Biology. I wish to write a computer simulation for cell differentiation. I understand there will be seemingly impossible challenges in doing this. But ...
3
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1answer
258 views

How do multiple replication forks function without 'colliding', and what is the benefit of this method?

I'm currently reading a little about DNA replication, and have come accross the following statement; Replication starts from a fixed point and is bi-directional ... In Eukaryotes, there are ...
8
votes
3answers
259 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 ...
3
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2answers
586 views

Difference between mice and rats

What is the actual biological difference between mice and rats? Are they actually the same thing with two different names depending on appearance (are they all mice for instance and we call the larger ...
3
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1answer
48 views

mutant down but not out

I am interested in a gene which is null lethal but I need to temporary induce diminished capacity. If a cell is homozygous is it possible to induce heterozygous phenotypes or a partial knockout from ...
3
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1answer
59 views

How are atoms in benzopyridines and benzopurines numbered?

I am well-aware of the numbering system used for the traditional bases, as seen below. My question is how are the atoms in the size-expanded bases seen in xDNA and xRNA numbered?
4
votes
2answers
4k views

DNA as an acid? [duplicate]

Possible Duplicate: Does DNA react in all of the ways most other acids do? Even if DNA is made up of nucleotide bases, it is said to be an acid. Why is this?
6
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1answer
96 views

What is the oldest example of DNA identified?

What is the oldest sample of genetic material (presumably DNA) identified? What are the prospects of pushing back much further into the geologic record?
9
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1answer
301 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 ...
2
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2answers
261 views

Translate DNA to Protein

Assuming the sequence shown is read left to right, what is the sequence of the protein produced? sequence: 5’-ATGTACTTCCATCTGGAATAG-3’ MY ATTEMPT: I know RNA is synthesized 5 to 3. This is ...
12
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1answer
257 views

Can DNA act as a translation substrate?

I get conflicting answers. One would think if it was true, it would be rather seminal and widely known. There are papers from Khorana[1], Holland[2], and Bretscher[3] (late 60s) that suggest that it ...
5
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1answer
205 views

How are DNA polymerase error rates measured?

It is well known that the first DNA polymerase, Taq, is quite error prone. Newer generation commercial enzymes that have either been isolated from different thermophile species or have been improved ...
2
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1answer
188 views

How to learn DNA Origami

Can you tell me is there any good softwares and tutorials which can be used to learn DNA Origami. I am new to this and want to learn from basics. Advance thanks for your help edited: INSILICO
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2answers
445 views

What distinguishes “coding” and “noncoding” DNA from each other?

I've been reading a bit about "junk DNA" and how much of our genome consists of this "non coding DNA" in comparison to "coding DNA". I'm just an interested layperson but I thought all combinations of ...
14
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2answers
2k 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 ...
4
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1answer
137 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 ...
3
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3answers
6k views

Evolutionarily speaking, why do humans have 46 chromosomes

In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Monkeys, chimpanzees, and Apes have 24 pairs (twenty-four pairs), for a total of 48. What caused humans to have 46? ...
8
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3answers
201 views

What would need to be discovered to prove there is extraterrestrial life?

Curiosity is on the Martian surface and is equipped with a slew of laboratory equipment. What would Curiosity need to discover to prove there is or has been life on Mars? Would it have to find DNA (or ...
6
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2answers
1k views

Why do DNA and RNA have the functions they have?

I know that there are two most important directions of genetic information transfer in living organisms: DNA->DNA and DNA->RNA. The first is replication, and the second is transcription. I wonder if ...
8
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1answer
647 views

Does every mitochondrion in a cell contain the same DNA?

I know that mitochondria of eukaryotes have their own DNA, more similar to that of bacteria than to the rest of the cell's DNA. I also know that a cell can have plenty of mitochondria, and I ...
8
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1answer
125 views

How realistic is to use DNA for long term storage?

This is mainly a followup question to the recent paper Next-Generation Digital Information Storage in DNA. Personally, while I agree about the data density of the format, I can't help point out the ...
6
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1answer
68 views

(Rough) Model for DNA evolution in E. coli genes

I need a model of in-gene DNA drift. I'm not interested in bacterial phylogenies alone. Here is what I understand: Sequences corresponding to genes have both exons and introns, but in bacteria the ...
6
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1answer
82 views

DNA modifications other than 5-mC/5-hmC/5-fC/5-caC in vertebrate genomes?

Other than 5-Methylcytosine and the more recently discovered 5-Hydroxymethyl, 5-formil and 5-carboxylcytosine DNA modifications found in DNA sequences, what are other DNA modifications present in ...
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4answers
2k 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?
5
votes
1answer
409 views

Primer Dimer / Hairpin Algorithms

What are the algorithms / methods in use for the calculation of primer dimers and hairpins? As an example, IDT's OligoAnalyzer tool will generate these analysis given particular sequences. The ...
7
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1answer
70 views

How does one measure the length of telomeres?

My questions are: What techniques are available for doing so? Are they destructive ? What is their accuracy ?
3
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1answer
641 views

What happens when cells in your body run out of telomeres?

In my biology book I read about an experiment where the genes encoding telomerase were 'knocked out', but they could still live a normal life and no adverse effects were noticed until the 6th ...
3
votes
1answer
181 views

What is the DNA/protein charge ratio?

To study DNA-protein interaction, I want to do a DNA retardation test by mixing the protein with DNA and afterwarts loading it on an agarose gel to see if the DNA migrates slower. I've found some ...
6
votes
1answer
142 views

Are there any DNA base sequences that are fully conserved between the genomes of all humans?

That is, they don't differ throughout the entire population. I understand of course that we can't DNA sequence every human, so by "fully" I mean there's an incredibly small probability of there being ...
12
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4answers
458 views

Why did high A+T content create problems for the Plasmodium falciparum genome project?

The main paper for the Plasmodium palciparum genome project (Gardner et al., 2002) repeatedly mentioned that the unusually high A+T content (~80%) of the genome caused problems. For example they imply ...
3
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2answers
123 views

How distantly related are eusocial insects? Aren't members of a species much more related than 1/4, 1/2, or 3/4? [duplicate]

Possible Duplicate: How many genes do we share with our mother? I went to a lecture that talked about the behavior of social insects in terms of their relatedness of genes. For instance, ...
6
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1answer
334 views

How can I predict DNA binding affinities from a protein sequence?

Are there any computational tools to predict the binding affinity to specific DNA motifs from protein domain sequence information?
8
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1answer
426 views

How many gigabytes of DNA are there on earth?

The human genome is about 770 MB, the C. elegans genome is about 100 MB, the yeast S. cerevisiae is about 12 MB. Different other genomes have been sequenced: how many GB of genomic DNA we have now? ...
5
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2answers
95 views

Do somatic cells alter their own nucleotide sequence?

I seem to remember reading that embryonic cells will frequently replicate the section of their genome containing rDNA by splicing in duplicate genes. The cells use this to produce ribosomes at a rate ...
5
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2answers
173 views

Are there other mechanisms for mutation besides imperfect DNA replication?

I was reading http://www.askamathematician.com/2012/05/q-is-quantum-randomness-ever-large-enough-to-be-noticed/ and saw: [...] the evolution of entire species can be changed by a single mistake ...