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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Why do some cells like myofibrils have multiple nuclei?

I see that myofibrils (muscle cells) contain not one, but multiple nuclei. Why is this so? Do all the nuclei participate in cell division?
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520 views

DNA content in plant seeds vs. fruit flesh

Is there a publication comparing DNA yield and/or PCR-amplifiability after extraction from fruit flesh (like apples, oranges, cherries etc) in comparison to seeds of the same fruits? I would prefer a ...
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195 views

Can cfDNA testing distinguish results in the case of twins?

A fetus can now be screened for some of the more common genetic diseases and its sex determined from just a whole blood sample from the pregnant mother. Fetal DNA is abundant enough in the systemic ...
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169 views

How fallible are DNA paternity tests?

Is it possible to get either a false positive or a false negative from a DNA paternity test and what would be the likely mechanisms behind this? For example, is it possible that a father's DNA could ...
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39 views

Superpatients for Cancer resistance

I was reading an article on MIT Technology review about superpatients for low cholesterol that got me thinking whether such patients exist for cancer. The article is ...
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185 views

Are there viruses that affect cells across different species?

I'm not a professional in biology nor a student, but I'm curious about this. To be more specific: why doesn't a plant virus affect animal cells? I suspect that different kinds of cells have different ...
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How is DNA Read

Little odd question here. I was told that DNA was read in groups of three. Assuming this, my question is: Which way would better describe how the DNA is read. (123)456789 to 123(456)789 to ...
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69 views

Will gene mutations give rise to a protein that is shorter than the full length protein?

What is the relationship between deletion or insertion of nucleotide in the gene sequence and the protein's length that is coded out from the mutated gene?
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907 views

Why are urban birds still scared of humans?

I understand that animals are naturally scared of humans because we basically slaughtered every living thing we found in our way for millennia. How long does it take for them to genetically 'forget' ...
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6k views

Why do the major and minor groove exist in DNA?

So I know that the major/minor groove arise from the offset pairing of the two strands in the helix. All my textbook tells me is that "pitch causes the off-set pairing of DNA and this gives rise to ...
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74 views

5,6-dihydrouracil and 5,6-dihydroxyuracil - how they arise in DNA?

5,6-dihydrouracil can be formed from cytosine after exposure of DNA to ionizing radiation under anoxic conditions [Ref]. What are other ways by which 5,6-dihydrouracil is formed in DNA? What about ...
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405 views

Is there a PSI-BLAST for nucleotide sequences?

I understand that one can translate a nucleotide sequence and run PSI-BLAST on the protein (proteins if you take the 6 reading frames), but I'm looking for distant homology for bacterial small RNAs ...
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308 views

DIY extraction and long term storage of human DNA sample?

What is the recommended DIY way of extracting and long term storing of human DNA samples to store at home and send for sequencing in years time? Considerations: Sample material: cheek swab, hair, ...
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580 views

Why does DNA have its name?

Why is DNA called deoxyribonucleic acid and not something else? I get the nucleic acid part (because that's what DNA is made of) but what about the deoxyribo- part, especially the ribo- part. Maybe ...
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Why is uracil used in RNA rather than thymine?

What is the advantage gained by the substitution of thymine with uracil? I have read previously that it is due to thymine being "better protected" and therefore more suited to the storage role of ...
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72 views

Why does the stability of YAC increase with size?

From Lehninger Principles of Biochemistry : The stability of YAC increases with size (up to a limit). Those with inserts of less than 100000 are gradually lost during mitosis. Why does this ...
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42 views

PCR cycle problem [closed]

IF I began a PCR cycle with 5 copies of a particular DNA section, and copied the section by PCR, for 6 cycles, how many copies of the DNA (include the originals) would I have by the end of these ...
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104 views

Is a single x-ray photon capable of doing enough damage to the DNA of a cell to kill that cell? [closed]

Ionizing radiation is damaging to DNA, but is there such a thing as a safe dose below which no DNA damage could occur? I'm not asking about a minimum safe dose overall, just whether or not there's an ...
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1answer
111 views

Low copy numbers of plasmids

I have a plasmid with the P15A origin which apparently has a low copy number (see here). This would explain why my purification yeilds for subsequent digestion are low (gel shows the plasmid after ...
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282 views

Ribosomal Turing Machines, DNA/RNA computation

I'm a computer science guy, recently crossing over to do some research in computational biology on RNA secondary structure prediction. While looking through the materials I got a crazy idea, what if ...
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127 views

Are there any similarities in the DNA of a humans and animals? [closed]

As the title says, i've been wondering if there are any similarities between the DNA of humans and the DNA of animals? Like, maybe monkeys are more similiar in their DNA to humans, than dogs are (to ...
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2k views

Why does A pair with T and G with C?

DNA is made up of pairs on AT and GC base pairs. I know that A only pairs with T and G only with C. Does this apply just to humans, or are there animals where T will pair with G? Also, surely there ...
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128 views

enzymes that stabilize DNA loops

As a follow-up of a previous question, I would like to know what enzymes or protein complexes have been used to manipulate DNA samples into stabilizing DNA loops. I have read that cohesin is one of ...
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83 views

Is the nuclear envelope present in G1 of interphase?

Is the nuclear envelope present in G1 of interphase of eukaryotic cell? If so how does a method like Calcium mediated transfection get DNA past the nuclear envelope?
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Importance of Double Helix DNA Structure

Gene expression involves transcribing only one strand of DNA molecule. So i was wondering what are some biological advantages of the double stranded DNA?
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160 views

Why is the threshold between human embryo and human fetus defined as 8 weeks after fertilization?

Why is the threshold between human embryo and human fetus defined as 8 weeks after fertilization? What's happening on the 8th week? Note: definition of embryo based on Wikipedia's current ...
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132 views

What are the costs associated with carrying lots of genetic material

What are the costs (if any) associated with carrying lots of genetic material (Big genome size)? energy for copying? raw material for copying? space in the cell? Maintenance cost (matter and ...
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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 ...
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What does 5' and 3' mean in DNA and RNA strands?

What are 5' and 3' in DNA and RNA strands? Please clarify with some images and please use simple English.
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116 views

Redundancy of the genetic code

One particular codon codes only for one amino acid, but an amino acid can be coded for by several different codons. Now according to the genetic code, the codon UUU ...
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129 views

What kind of technology is required for plant seed DNA printing? [closed]

I'm a programmer so I have little knowledge in the field of biology. However I have an interest in plants, GMOs and DNA (in terms of programming). So, I want to know what kind of technology is ...
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139 views

How does high-fidelity of DNA replication depend on the formation of hydrogen bonds?

Replication has an error rate of less than 1 in 100 million. DNA polymerase forms H-bond with the H-bond acceptor atoms in the minor groove. <-- enhance fidelity here? Binding of the triphosphate ...
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How does non-homologous end joining (NHEJ) work?

I was reading about non-homologous end joining (NHEJ) in my molecular biology of the gene textbook but the explanation provided in the text was rather vague to me, and I was not able to understand it ...
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1answer
5k views

Does DNA replication in 5' to 3' (leading strand) need RNA primase?

https://www.youtube.com/watch?v=27TxKoFU2Nw In the above video it shows that during DNA replication, the lagging strand require RNA primase to add 3' -OH group for further addition of nucleotides. ...
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Gibson assembly - primer design with A and T rich regions

I have question about Gibson assembly. I have done it several times and it always worked okay for us, but now I want to assemble together a fragment which has sequence like this: ...
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379 views

Why do our epiphyseal plates close up in our late teens or early twenties?

What causes our epiphyseal plates close up in our late teens or early twenties? I realize that one's genetics plays the main role in this. I assume there is a gene that controls the epiphyseal plates ...
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94 views

If DNA is the input, what is the output? [closed]

How does cells use the DNA inside them? I am looking on DNA as a strip of tape of Turing machine, but with machines its easy. I can read the tape and calculate the behavior of that machine. With cells ...
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107 views

Chromatids in metaphase?

Please see the following picture: In my book, the author claims that these chromosomes are in metaphase (a metaphase stopped by cholchicin). I don't understand why they don't have two ...
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95 views

Are the DNA codon mappings arbitrary?

I am a Biology novice so I apologize in advance if I state anything incorrectly.... My question is, are the DNA codon mappings arbitrary? I understand that the DNA code is made up of codons which ...
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1answer
40 views

programmatic fast search of 100-1000 short reads to a public server and obtain list of nearby genes

What are the options for programmatic fast searching of 100-1000 short reads to a public server and obtain list of nearby genes where the reads map? Input: ~100-1000 short reads Output: GFF list of ...
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58 views

How to identify genes?

You and me are different at DNA level. My eye color gene is different from yours. So, my DNA is different from yours. How can a scientist identify a certain gene in a chromosome (and its function) if ...
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108 views

What percentage of DNA do people share?

If you picked two people in the world at random, sequenced each of their entire genome, and compared their DNA, what would the expected percentage match be?
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Separating DNA Fragments by Gel Electrophoresis. Are all the strands for one size the same?

My apologies if my question is too basic, and please point me to a more appropriate forum. I am reading the textbook "Essential Cell Biology" by Alberts et al, and am consulting other sources as ...
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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 ...
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Does our DNA change during our lives?

As far as I know, DNA is the construction protocol of all organisms on Earth. Does it change when influenced by time and environment (physical laws)? As parents with schizophrenia are more likely to ...
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Why is DNA replication performed in the 5' to 3' direction?

DNA replication goes in the 5' to 3' direction because DNA polymerase acts on the 3'-OH of the existing strand for adding free nucleotides. Is there any biochemical reason why all organisms evolved to ...
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1answer
99 views

How is the rate of transcription influenced by temperature?

How is the rate of transcription influenced by temperature? More precisely, I am looking for an article who quantitatively measured the rate of transcription of an "average gene" and show how this ...
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32 views

Transcription rate expressed in microarray per hour

This article gives measurement of transcription rate and the unit they're using is microarray per hour. For example, at 27°C the average expression of their genes is 236.1 microarray per hour (page ...
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70 views

where to find the relative frequency distribution of synonymous codons

Most amino acids can be encoded by more than one codon. For example, Serine can be encoded by any one of ...
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164 views

What is most simple eukaryotic genome?

Expressed in number of Base Pairs or Bytes, about how large is the simplest eukaryotic genome? How much of this is 'junk-DNA' (non-coding)?