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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Difference in length of Okazaki fragments

The length of Okazaki fragments in the lagging strand is about 100-200 nucleotides in eukaryotes and about 1000-2000 nucleotides in prokaryotes. What (molecular mechanism, enzyme type ) ...
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176 views

How much natural genetic variation is there between bacteria of the same species?

There are lots of questions about how and why there is genetic variation between organisms of the same species, but I haven't been able to find a numerical value for the expected amount of genetic ...
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350 views

Are all body atoms really recycled several times during a life?

I heard a point, that all (human) body atoms are recycled withing short period like few years. Recycled means "old" atoms are replaced by "new" ones during metabolism, leaving only structure ...
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102 views

Should the length of the electrodes in the electrophoresis chamber be proportional to chamber's size?

I am trying to build a small horizontal electrophoresis chamber from scratch. I want to use it for comet assay and I will be using only 1 slide, so it's going to be about 3cm wide, 10cm long and 4cm ...
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438 views

What is Luc Montagnier's research on electromagnetic signals from DNA about?

After reading a Youtube comment, I started reading on Luc Montagnier's research on electromagnetic signals from DNA. I haven't been able to find a source that would clearly explain what it's about. I ...
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146 views

Microarray data and analysis tools

Microarray has various uses, and to analyse the data a main function classification is used. There are many methods used to classify the data but what are the best and most frequently used methods? ...
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41 views

Reassociation of DNA

What is the order in which this DNA samples would would reassociate ? e.coli DNA plasmid DNA viral DNA satellite DNA DNA-RNA hybrid This is a homework question and I have not been given any ...
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90 views

What to do with a DNA sequencer? [closed]

My school is very fortunate to have a DNA sequencer, and I want to find an opportunity to learn how to use it. I'm currently taking AP Biology this year, and I hope to do an independent study in ...
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113 views

Would it be correct to state that any biological difference between the sexes has to be found in the Y chromosome?

If the reason Why Men Don't Listen and Women Can't Read Maps is genetic, then one of the genes in the Y chromosome is to blame and in theory could be identified. Correct or incorrect?
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31 views

Genotoxic agent and their metabolic pathway

What are the mechanics (set of biochemical reactions) allowing a given genotoxic agent to modify the mutation rate at a given spot? to induce only a given type of mutation (from Gs to Cs for ...
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55 views

Is telomere shortening consistant over consecutive cell divisions from zygote to a differentiated cell?

Considering the complexity of embryogenesis, a temporal referance would be helpful to coordinate the developmental sequences during embryogenesis and fetal development which is to be completed within ...
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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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172 views

Basic text/notes on DNA structure (for non-biologists)

I am a mathematics grad student researching knot theory, and I've recently discovered that there is a connection between knot theory and DNA structure (if I understand correctly, when DNA strands ...
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188 views

Which organisms have introns?

From Wikipedia: For example, introns are extremely common within the nuclear genome of higher vertebrates (e.g. humans and mice), where protein-coding genes almost always contain multiple introns, ...
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262 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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1answer
108 views

Do spouses begin to share genes over time?

I apologize if this hypothesis sounds strange by I was wondering if any research had been done on a phenomenon which I've seen and have corroborated with many other - the idea that over time spouses ...
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100 views

There are linear and rotary molecular motors in the cells. Do any of them have a fixed or stable frequency or speed?

Are there any linear, rotary or oscillatory molecular motors in the cells which can have fixed frequeny and which can be used as a reference for elapsed time timer? This question is with relevence to ...
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1answer
58 views

How correlated are proximally related CpG sites in human DNA?

Cytosine residues in DNA that can be methylated (i.e. CpG sites) are likely to be in the same methylation state if they are geographically (proximally) close together. I can only find one paper that ...
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73 views

Complementarity of cDNA

Strictly speaking, what is the definition of cDNA? This confuses me, since usually it is said to refer to DNA that is complementary to mRNA. Is this correct? Is it restricted to mature mRNA? I ...
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269 views

Why Only DNA can Contain Hereditary Material?

Well I'm well aware that it is proven that DNA contains genetic material via transformation and Hershey-Chase Experiment of T2 bacteriophage. Still I was wondering what is the reason only DNA ...
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218 views

Can replication occur if DNA is methylated?

Can a methylated strand of DNA be replicated without removing methylation? Does it make any difference if the strand is methylated or not (during replication)?
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465 views

Does RNA polymerase move around DNA or does DNA rotate benath the polymerase?

I'm thinking of the human genome specfically, but more general answers are welcome. As RNA polymerase moves along the DNA helix it follows a single strand. The two DNA strands are unwound locally ...
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2answers
109 views

Can retroviral delivery systems “overwrite” genes?

As the question states, what are the limits of retroviral genetic delivery systems? Are they limited to adding additional gene sequences to a cell, or can they actually overwrite specified segments ...
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3answers
322 views

Is there variation of AT/CG ratio along species?

Chargaff's rules say that the number of Adenine of the number of Thymine in a genome are equal (nA=nT) and similarly nC=nG. This makes obvious sense knowing that C binds to G and A to T. But what ...
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144 views

How does electroporation mediated recombination work?

For yeast and other organisms, DNA can be readily taken up into the cell naturally or through membrane disruption. What does applying a voltage to cells do exactly that allows more recombination to ...
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76 views

Do mitochondrial DNA have repair enzymes?

Mitochondria are considered endosymbionts originated from a prokaryote. So, do they have a DNA repair mechanism ?
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122 views

Suggestions for an experiment? [closed]

I would appreciate suggestions for my year-long AP Biology project. Such a project would consists of a standard experiment, to be done over the period of a year, so it would have >to be fairly ...
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182 views

How to deduce if RNA virus infection or DNA virus infection

Is there any general rule to say this must be RNA virus infection and the other one DNA virus infection? Example of a case: 5 children develop a bright red rash on the face and turns violet after a ...
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820 views

What is DNA binding domain? It is not clear what the domain means

I am confused about the term DNA binding domain. Does it mean that there are some parts of the DNA that tends to coil up? Does it happen because some proteins tend to stick around that area? Also it ...
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63 views

How do I figure out which of the valleys I came from?

I had my DNA tested by 23andme.com. They give me a very long string for my DNA. How do I determine which of the three Ethiopian valleys I descended from? I'm of European descent. ...
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1answer
602 views

Difference between viral and human genetic material

I have heard that there is a difference between viral and human genetic material. What is that difference? If I take my cells and take DNA out of them and insert only a small part of it having a ...
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1answer
88 views

What triggers DNA to produce proteins?

What is the trigger for DNA to produce proteins or RNA? I have found enough material to study the inner workings of the cell and DNA; but, I can't find an explanation of the mechanics the cell uses ...
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499 views

When can a virus modify DNA in every cell of a living organism?

I've recently heard about experiments with brain tissue, where a virus is introduced in a rats brain, causing a "glow when electric charge is present" protein to be created. This protein then helps to ...
3
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49 views

Self pairing in DNA

I know that ssRNA molecule can fold over itself (e.g. in t-RNA). Can DNA do the same? Is there any example of this in nature? Why is this phenomenon more common in RNA than in DNA?
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90 views

What is the mechanism of labeling a DNA molecule with deuterated water?

I have seen a paper in which deuterated water was used to follow dividing cells. The assumption was that deuterated water will be incorporated into newly synthesized DNA molecules. Is there any direct ...
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Why can't we observe haplotypes directly?

I am completely a noob to biology and DNAs, but recently I am looking into EM-algorithm used in the case of re-constructing haplotypes from genotype data. I am just wondering what exactly in the ...
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Do apes and humans share 99% of DNA or 99% of genes? What is the difference?

I made an answer on the Scifi.SE that can be read here. It is about how the characters in the story Jurassic Park might have gotten DNA for all the species shown. In my answer, I said this: Apes ...
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78 views

How does the DNA know which chain has error in repairing?

As we know, the DNA has more stability than RNA, if one chain has broken or accidentally distorted, it can be repaired by the other one. Suppose there is a segment AGTC, its peer is GACT. Now its ...
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113 views

DNA Replication

I just wanted to understand the basic steps behind the replication of the lagging strand of DNA: Have helicase unwind it first DNA Primase lays down RNA primers in fragments, called Okazaki ...
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282 views

Mitochondrial DNA and recombination

Firstly I could do with a brief description of mitochondrial DNA. How does the structure of DNA in mitochondria compare to animal DNA (for the sake of simplicity let's say human - some animals might ...
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1answer
143 views

Do thymine and uracil ever appear in the same strand of RNA?

Wikipedia says that "in RNA, thymine is replaced with uracil in most cases." I'm curious what are the cases when this does not happen? Does this ever occur in normal functioning, or is it an error? ...
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101 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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194 views

Can a dNTP be built into a RNA strand?

DNA consists of deoxyribonucleotides, RNA consists of ribonucleotides. They differ mainly (apart from the uracil / thymine difference) in the sugar part, the deoxyribose and the ribose. Those two ...
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Is there any other function of DNA?

We all know that DNA acts as a genetic molecule. Does DNA have any other function in the cell other than being a genetic material and carrier of information?
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Are there beneficial genetic mutations identified by consumer DNA genotyping?

I'm looking at services like 23andme, and see that they identify a wide variety of genetic-based risks, like predisposition to diseases, hair loss, cancer, etc. Are there a more "positive" DNA ...
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349 views

Transcription factor binding site located in intron

I have noticed that some TF binding sites are located in the introns of the genes. I am puzzled about whether the TF only binds to DNA in the initiation stage of transcription and will detach during ...
5
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132 views

Is there a DNA test to identify dog mixes?

We adopted a dog at the age of two. Our vet said it was a mix of an Australian Shepherd and Border Collie, which we've told everyone. Based on markings, I think it's likely. I am wondering, however, ...
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2answers
121 views

Prenatal Marketing

This is for a short story idea. Is it possible to modify the DNA of a child to make their metabolism more susceptible (physical response, addiction, etc) to a certain type of chemical i.e. a chemical ...
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1answer
96 views

Superposing DNA

I have a series of protein models with DNA docked. I now want to superpose the DNA on a reference DNA molecule and extract the translational distance applied and the rotation angle used. I can ...
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878 views

What is the purpose of Y-shaped adapters in Illumina sequencing?

Y adapters different sequences to be annealed to the 5' and 3' ends of each molecule in a library. The arms of the Y are unique, and the middle part, connected to the DNA fragment, is complementary. ...