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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Converting Ensembl Compara gene tree DNA alignment to corresponding amino acid alignment

I have Ensembl compara gene tree alignments (Compara.gene_trees.57.fasta.gz downloaded from ftp://ftp.ensembl.org/pub/release-57/emf/ensembl-compara/homologies/) in nucleotide format. According to ...
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70 views

How does DNA resolve on size exclusion resin?

We generally have a good idea of how DNA separates using agarose gel electrophoresis, how well does DNA resolve on a SEC resin like superose? I get the impression that salt influences where it elutes. ...
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Maintaining purebred pedigrees and how to lessen chance of getting disease?

Many breeds of dogs are known for a high incidence of genetic disorders. German shepherd and Saint Bernard dogs are predisposed to developing a crippling condition called hip dysplasia. Q: What ...
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123 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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151 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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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 ...
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242 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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Nucleosome wrapping direction

Does anyone know which direction the nucleosomes are wrapped? I wonder: Relative to the B-DNA double helix twist direction (right-hand) Relative to the neighbor nucleosomes. Do they alternate to ...
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Mitotic crossover happens in G1?

I was reading this article in wikipedia and came across this : It has been suggested that recombination takes place during G1, when the DNA is in its 2-strand phase, and replicated during DNA ...
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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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117 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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If everybody DNA is different then how blood can match even with matching blood group?

We know that everybody's DNA pattern is different in the world. Then how can ´we transfer blood from one person to another person and this person can survive ?
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530 views

Gel electrophoresis after RNAse treatment

I do not understand how to solve this question. I know that RNAse will cut smaller pieces of RNA. The answer given is A
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76 views

Functioning of EDTA

I know that EDTA chelates metal ions. It weakens bacterial cell wall and inactivates the DNases. What is the reason why it can do so ? I guess it can inactivate DNases by altering the ...
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87 views

Do individual (free) nucleotides base-pair with other free nucleotides?

I had a student ask me about this and my google-fu let me down. He asked if individual nucleotides (not in a nucleic acid) base-pair with their complementary nucleotides, essentially forming many ...
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80 views

Removing a restriction site and introducing other at its place

What would you do if you want to remove an EcoRI restriction site and introduce BamHI restriction site at apprx. the same location ? One of the answers in my textbook was : To construct a DNA ...
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94 views

Generating custom human DNA sequences based on traits such as eye colour?

I'm wondering if it would be possible to create software (unless some already exists, but I couldn't find any) to generate human DNA (the base pairs on the double helix) containing genes representing ...
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73 views

How are 23 chromosomes in human sperm chosen?

I'm not biologist and I have just a basic knowledge. I've been thinking for a long time about the following question: How does the body choose which 23 chromosomes should be active in human sperm and ...
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33 views

DNA barcoding and real-time PCR

I recently read an article on how DNA barcoding was used to identify species present in health products. I also read an article about how Real-Time PCR was used to identify meat species in meat ...
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124 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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42 views

How does the size of insert affects the rate of Homologous Recombination in yeast?

When performing genetic knockouts in yeast using homologous recombination to replace a target gene sequence via a vector DNA, does the region between the flanking regions in the vector have to be the ...
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34 views

The damage of cancer cells

I read about the molecular biology of cancer, and I have a mess on my head and a lot of questions.. . My primary question is- The damage of the cancer cells is in the dna sequence or in the gene ...
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65 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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80 views

Do “transcription factor binding site” and “operator” mean the same thing?

Can the terms "transcription factor binding site" and "operator" be used interchangeably in all contexts when referring to a DNA sequence, e.g. regardless of a cell type, whether or not the binding ...
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68 views

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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53 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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Conclusions from hybridization results

A double stranded DNA was denatured in a mixture that included mRNA from a gene in the segment. The mixture was then cooled to promote RNA and DNA hybridization. The following figure the results. ...
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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)?
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87 views

Understanding DNA supercoiling

While trying to understand DNA supercoiling, I came across these lines in the book Genetics by Ursula Goodenough : All natural DNA is superhelical. The axis of the duplex itself follows a ...
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178 views

Codon alignment via Python? [closed]

I have pairs of coding DNA sequences which I wish to perform pairwise codon alignments via Python, I have "half completed" the process. So far.. I retrive pairs of orthologous DNA sequences from ...
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1answer
148 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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3k views

Is episome a plasmid or a virus?

A plasmid is a small DNA molecule that is physically separate from, and can replicate independently of, chromosomal DNA within a cell. In general, in eukaryotes, episomes are closed circular DNA ...
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84 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
39 views

Can life forms exist from simple structures not made of the four bases? [on hold]

I understand that all life forms on the planet are made from adenine, gauatine, cytosine and thymine, which chemically joined together to form RNA or DNA (correct me if I'm wrong). This goes on to ...
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33 views

How do I find a protein from this DNA sequence?

I have a DNA sequence from a sequencer. How can I determine what protein is it? I tried some translator but it didn't help. What protein is this and how can I determine it? The sequence: ...
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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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53 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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1answer
95 views

Percentage of understood human DNA [closed]

I want to know what's the approximate percentage of understood human DNA, as in, which part does what. I'm not asking for details, just the amount. Thank you.
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34 views

Concentration of DNA by isopropanol

I have read that DNA can be concentrated by addition of isopropanol. What does "concentrated" mean? What does isopropanol do on a molecular level to concentrate DNA?
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2 types of telomerases?

As telomerase works by adding new nucleotides complementary to the RNA it contains, it cannot work for the complementary strand. Say telomerase X has RNA complementary to the 5' to 3' strand it ...
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65 views

In vitro transcription, contamination problem

I am using a RNA which is in vitro transcripted before I started my project. It turned out it is not prepared properly and has DNA contamination. Instead of perform the in vitro transcription again, ...
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Clarification of the procedures to amplify cDNA needed

The typical procedure to obtain cDNA from genomic extracted DNA is the following: RNA is extracted from desired tissue, RNA/DNA hybrid is obtained by virtue of reverse transcriptase RNA dependent DNA ...
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Why use DNA polymerase in making cDNA?

RT is capable of synthesizing a complementary dna strand ( as in HIV life cycle.) Then why is DNA pol used when cDNA (synthesizing the second strand of it ) has to be synthesized from mRNA ( For eg.to ...
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How do genetic chimeras with different blood types not die?

If a person is a chimera and has two different blood types in his veins, how does he not die? Shouldn't the immune system attack one of the blood types? In 1953 a human chimera was reported in the ...
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130 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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75 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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68 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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75 views

Has it been confirmed yet that the DNA found in dinosaurs was really DNA?

I hear different sources claiming different things, bbc said they did, wikipedia says it hasn't which is it?
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42 views

Mechanism of DNA gyrase inhibitor

Why DNA gyrase inhibitor, such as Nalidixic acid and Norfloxacin, do not stop gyrase from cutting DNA helix but only prevent them from decatenation replicating DNA?