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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How to safely conserve my current DNA methylation marks?

I read the Wikipedia article on DNA methylation Let's say I want to extract and then stock my current DNA methylation marks somewhere so that I can use it safely 20 years in the future for a medical ...
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79 views

Does cancer cells come from same process as evolution? [duplicate]

Here is how I understand it: DNA replication is not 100% perfect and error can happen, this error can be good(evolution) or bad(cancer properties). But its not the only source of cancer cells - DNA ...
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1answer
106 views

How to read this DNA inversion diagram?

In the following diagram about chromosome inversion, I don't understand: Why do we need to take the reverse complement from step 1 to 2? Isn't inversion just reversing the bases in the region? How ...
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Do plants have distinctive DNA genomes from each other like humans do?

Can exact same species of plant have a distinct genome from others of same exact species growing nearby or in a different place/country etc. ? Can a leaf be traced to the the exact plant based on DNA ...
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1answer
44 views

How much of the Neanderthal genome is living on in humans?

I've understand that outside of African, most ethnic groups carry some (4% or less) Neanderthal DNA. So en masse, across all living humans, what percentage of the original Neanderthal genome is still ...
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1answer
340 views

In percentage, how much is the human genome (DNA) similar to the mouse genome?

Some guy argued with me against evolution theory, and he claimed that human and mice share 98% just like human and chimpanzee. I've tried to search online for a simple and accurate answer, but I ...
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1answer
62 views

Questions on adding a protein to a DNA library [closed]

Two questions regarding finding the DNA sequence of a amino acid sequence (AA): 1) If you are able to find out the mRNA sequence of an AA, then don't you automatically know the DNA sequence? 2) ...
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2answers
62 views

What is the length of the centromeric repeat sequence in a human?

I'm looking for the lengths of the centromeres of human chromosomes. The best I could come up with so far has been: The length of individual centromeric arrays was found to range from an average of ...
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0answers
37 views

can you tell someone's age from a DNA sample? [duplicate]

So as I understand it telomeres shorten as you age. Working under that assumption.. let's say you were investigating a crime and there was some DNA evidence that had been left behind. Could you ...
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34 views

Minichromosome maintenance protein structure and function

I am having difficulty answering three homework questions which relate directly to Chong et al. (2000). Questions The authors have determined that MtMCM is able to bind both ssDNA and dsDNA (see ...
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1answer
87 views

Why does Taq polymerase add 3' adenine overhangs?

Is there a mechanism for the preference of Taq polymerase to add a non-templated 3' adenine (overhang) instead of other bases?
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28 views

How Did They Know What To Do ? And Cellular Identification [closed]

So this is regarding Science, generally, it has influence throughout each section science. How did the early age Scientists etc. knew what is to be done to achieve a certain thing ? And by that, I ...
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1answer
885 views

Why is DNA double stranded and RNA single stranded? [closed]

Why is DNA present as a double helix structure and RNA as a single helix? What causes the difference between them? What are the practical physiological differences between dsDNA and ssRNA? How are the ...
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34 views

Mutagenic Agent [closed]

This was a passage in University Degree Genetic Journal that confused me. DNA base pairs are more susceptible to mutagenic agents, so this reduces the chances of spontaneous mutations happening ...
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0answers
31 views

Determine OTU identity using Blastn full database or organism specific database?

I am seeking opinions on the best way to determine OTU identity using Blastn. Would the best way to identify an OTU be to blast the OTU to the full nr/nt Nucleotide collection or to blast your OTU to ...
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2answers
76 views

What is the meaning of the “d(…)2” notation when writing a DNA sequence?

When the sequence of a DNA oligo is written as d(CGCTAGCG)2 what is the meaning of the d(...)2? Why would it not simply be ...
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1answer
28 views

Pooling already extracted dna?

I had ethanol precipitated a large amount of DNA (2ml) and had to split the sample in half to spin down because only the microcentrifuge has the correct rotor to spin that fast. I want to get as ...
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1answer
78 views

How to improve DNA extraction

I am using the following protocol to extract chromosomal DNA from bananas: Cut up one banana into small pieces, approximately (1 cm3) Add ½ a cup of warm salt water and the banana pieces into the ...
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2answers
182 views

if sperm contains only 50% of someone's DNA how can it be used to identify someone?

Is DNA so unique that 50% of it is enough to identify a single person?
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Strand directed mismatch repair system?

In SDM (strand directed mismatch repair), random correction of DNA (correction of template strand) is not right. For example if G (from template strand) gets joined with the T (it should have actually ...
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0answers
235 views

Construct a restriction map of a linear fragment of DNA using the following data?

I've attempted to do the single digests, and the double digests, but cannot complete the map.... I've attached what I've done so far DNA Sizes of Fragments (bp) uncut DNA 900 DNA cut with EcoRI ...
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28 views

Do eukaryotes assimilate DNA that is floating in the extracellular membrane?

Prokayotes, which replicate primarily using binary fission, don't get much genetic diversity. For this reason, they take in any genetic material they encounter, in a gambit to help them better adapt ...
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29 views

DNA binding Domain [closed]

How to say whether a specific amino acid in a protein is binding to DNA or not from sequence alone and what are the features or characteristics to be considered?
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0answers
21 views

Do you have a comprehensive protocol using xGen blocking oligo? [closed]

Specifically used with genomic DNA and to help prevent non-specific binding
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1answer
105 views

What is two-start or zigzag model of 30 nm chromatin fibre?

I read some webpages describing the two-start model but could not get it. I'll be obliged if someone helped me understand the topic. The websites I have been through are: 1.http://www.nature.com/nrm/...
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1answer
150 views

What is positive and negative supercoiling?

Is the following correct? Positive supercoiling = the coiling of DNA helix (B-DNA) on itself during intesified coiling of the two DNA stands in right handed direction negative supercoiling = the ...
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How do the major and minor grooves in the DNA helix arise?

I understand that they arise due to the pairing of bases of two opposite stands and are sites through which important proteins needed for replication and transcription of DNA interact. But I don't get ...
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From DNA to final traits of microorganisms? [closed]

From the answer of this topic, could someone indicate me a book or article about how DNA set the phenotype of microorganisms? For example, showing how DNA changes the shape of such a cell or how DNA ...
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28 views

Color of DNA, available absorption energy levels of DNA molecule, mutations

I have done a couple of DNA separations and observe that the clumped strands of DNA are white. Is that an artifact of the chemicals used in standard separations? Or is it indeed the case that the DNA ...
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Is Chargaff's rule really applicable?

Chargaff's rules states that DNA from any cell of all organisms should have a 1:1 ratio (base Pair Rule) of pyrimidine and purine bases and, more specifically, that the amount of guanine is equal to ...
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28 views

Hydrogen bonding and the blocking thereof in nucleic acids during nuclear processes

In transcription, RNA polymerase unwinds the DNA double helix and begins attaching RNA nucleotides to the template strand. In its wake, the DNA double helix closes back—this is only natural, seeing as ...
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1answer
60 views

Does DNA polymerase I require a $3^\prime$ end?

DNA polymerase III adds nucleotides in the $5^\prime \rightarrow 3^\prime$ direction because it can only add nucleotides to the $3^\prime$ end of the previous nucleotide. This is why it requires a ...
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0answers
23 views

Infer type of nucleic acid based on number of nucleosides

Lets say we analysed a nucleic acid and found out that it had 20% Adenosine, 25% Guanosine, 40% Thymine and 15% Cytosine. We know that A always pairs with T and G with C. So, based on these numbers, ...
3
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1answer
78 views

Distinguishing Father from Brother

Given the (non-identical) DNA sequences of two men and the knowledge that the second man is either the father, brother, or son of the first man, is the DNA useful in determining which of these three ...
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Separate replication origin and terminus vs making them one and the same

The classical picture of bacterial reproduction has a replication origin on one side of the circular chromosome and a replication termination area on the opposite end. This essentially creates two ...
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Is the DNA different in each type of cell? What DNA is passed to offspring?

Our body contains many different types of cells and each of those cells have their own DNA (correct me if wrong) like skin cells their own DNA that makes them skin cells instead of muscle cells. So ...
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1answer
92 views

How many Watson-Crick + Hoogsteen triple base pair combinations are there?

Are these triple base pairs the only Watson-Crick + Hoogsteen triple base pairs possible? Furthermore, are TAA and TAT mixed up? This image is from Wikipedia, so it's possible that it's erroneous.
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24 views

Transgenic Plant-Gene source for introduction into host organism

Let's say the plant-gene itself is known, i.e. the exact neucleotide sequence is available in a gene bank (originally sequenced from a tree sample extracted RNA). Previous work has already successfuly ...
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0answers
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Was the frequency of mutations more during primitive earth due to radioactivity?

Primitive earth was more radioactive (or was it really?) according to radiometric analysis of C14 which suddenly appeared at 4250 million years in the Hadeon eon. Is it possible that ancient high ...
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1answer
58 views

What does “~mitochondrial DNA ~bp linear DNA” means?

I'm surfing NCBI website -Nucleotide- to find some examples of real DNA sequences to use in my small homework project. My question is related to the title of a DNA sequence below: Sus scrofa ...
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1answer
35 views

BWA-MEM single strand or doublestrand alignment

In whole genome secondary analysis does BWA-MEM use a double stranded fasta reference or are reads aligned to only one, single stranded fasta reference?
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1answer
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DNA Topology. Question on twists and writhes

Hi guys there is a question which has been driving me crazy ever since I saw this video(https://youtu.be/az2c6UbEdug). At 4:50 the guy says that when a right-handed circular DNA starts forming a right ...
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1answer
47 views

Why do Major and Minor grooves exist in dna strands? [closed]

I've been trying to find what causes the periodic appearance of major and minor grooves in DNA but have not yet been successful. Geometrical explanations would also be appreciated as I cannot ...
3
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1answer
56 views

How does the splicing enzyme recognize where to splice the introns?

When the DNA from the nucleus is transcribed to an mRNA, the mRNA is spliced by an enzyme before it goes outside through the nuclear pore. What is the name of this enzyme and how does it recognize ...
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1answer
194 views

Is DNA replaced after organ donation?

If an organ from person A is transplanted to a new human body B, is it possible that we can detect A's DNA in B? How long until the organ's DNA is replaced by B's DNA so that we are no longer able to ...
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2answers
51 views

“Prime” structure of DNA Double Helix: Confusion

In this video on DNA replication, the diagram shows the unwound DNA as still being anti-parallel, but the first diagram in this post on Biology SE shows that the individual strands are 5'____5' and 3'...
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1answer
124 views

The Semi-Conservative Model of DNA Replication: Question

My Campbell's Biology textbook contains the following diagram related to the semi-conservative model of DNA replication proposed by Watson and Crick. I have highlighted where my confusion arises in ...
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0answers
35 views

Is DNA transcription inactive during mitosis ie no proteins are made? How does the cell survive?

I've read that during mitosis, DNA exists as heterochromatin, a form that is unable to be accessed for transcription. Does this mean no new proteins are made during what can be 20% of a cell's life? ...
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1answer
39 views

Constant or variable number of chiasmata during recombination?

During recombination, is the number of chiasmata consistent for each gamete and are the chiasmata regions consistent within a single organism?