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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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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6 views

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 ...
3
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1answer
80 views

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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28 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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19 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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1answer
36 views

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
31 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
17 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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22 views

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
35 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
30 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 ...
5
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1answer
130 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
35 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 ...
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40 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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22 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
20 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?
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1k views

How old is the oldest intact DNA?

DNA fragments are known from bone fragments from the Mesozoic, but these don't count. I'm guessing the oldest DNA is recovered from permafrost, but how old exactly?
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7 views

Where can one find completed and processed Hi-C datasets?

I and a statistics graduate student at UCR, and I am working on Optimal Binning schemes and peak detection in Hi-C data analysis (a dataset that conveys information about proximity of a DNA strand ...
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1answer
47 views

Are nucleotides at the ends of DNA stripped on aging?

I had the following understanding (now after reading a popular science article seeming wrong understanding): DNA in (regular) cells (in human and some other organisms) are protected by telomers. ...
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1answer
16 views

DNA extraction for LAMP assay

I am trying to set up a LAMP assay (Loop-mediated isothermal amplification) for the detection of E.coli. I was told that EDTA can chelate the Mg in my reaction and thus prevent the assay from working ...
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17 views

Why only human have noticeable difference in face? [duplicate]

Our facial appearance is pretty much different from each other unless we are talking about twin. Credit goes to crossing over of chromosome. But why can't we distinguish between other animals of same ...
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1answer
136 views

Why are the genomes of Humans 99.5% the same?

Human's DNA sequence is said to be roughly 99.5% equal. As far as I understand, this means that if I walked up to you and compared our DNA, the sequence of base pairs would be 99.5% the same. My ...
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10 views

final control prior to transfecting an expression vector into a mammalian cell?

I have been asked a general question: Once I have cloned a full-length cDNA into an expression vector, what final important control must I do before I transfect this into an embryonic stem cell line? ...
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41 views

Which DNA fragments do not have expected sizes on this gel electrophoresis?

The problem is such: After performing a PCR, the vector carrying the PCR fragment with two restriction enzymes (Nhe1 and Asc1). The DNA samples were then separated using agrose gel electrophoresis ...
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1answer
77 views

why is cellulase not found in animals? [closed]

As it is really beneficial for all organisms, why are animals, especially mammals (I don't know about other vertebrates) unable to synthesize cellulase enzyme in their body? Is it linked to some DNA ...
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3answers
124 views

Why don't housekeeping genes have TATA Box regions in their promoter sequences?

Housekeeping genes are genes that are continuously transcribed. Like all other genes they have promoter sequences, but they don't have TATA box sequences that are used to specify from where ...
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1answer
37 views

what are examples of experimental designs on exposing materal for degradation

if one wanted to compare how sources of DNA would degradate in various conditions(environmental) how would they do this in an experimental fashion but also be best comparable to real world examples of ...
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39 views

What are the effects of non-ultraviolet light radiation on DNA?

I am trying better understand the effects of varying the frequency of light on DNA, however, most of what comes up is "UV light" and how it is damaging to DNA (presumably by ionization). Have there ...
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1answer
36 views

Can you force human body to mass produce specific proteins? [closed]

I've had difficulty finding an answer to this question on Google. From what I've been taught, DNA is used as a "naive blueprint" to synthesize proteins. If we can manipulate DNA (Which I hear we ...
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19 views

What are flagged primers?

I'm interested in amplifying a sequence for further use with Gibson Assembly. I want to create overhang regions in my DNA fragment so there would be complementarity to the plasmid I'm trying to insert ...
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42 views

Insertion of synthetic DNA sequence

If I have some synthetic DNA sequence (<=20 bp long), is there a way for me to reliably insert this sequence next to some n-bp motif? I'd like for this to be possible in humans. If so, are there ...
7
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1answer
80 views

How can I generate a random DNA sequence?

I've found this paper which involves the construction of 19-bp random DNA sequences, but I don't know enough biology to understand how this method works. Could someone explain it to someone who is ...
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1answer
32 views

Time needed for transcription of DNA [closed]

How much time would it take to complete the transcription of an average-sized human gene?
5
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1answer
92 views

How do electrons destroy DNA bonds in radiation?

Malignant tumors can be treated by radiation therapy. Most commonly it's radiotherapy with photons, or protons and so on. The common denominator for both types is that the radiation creates electrons ...
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28 views

How do cell repair mechanism ratios change as they age?

I have seen that embryonic stem cells are shown to use homologous repair for double strand breaks rather then non-homologous end joining (NHEJ). [1] I am wondering if something also happens to a ...
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53 views

Homework Question: Confused about figure related to cDNA and gDNA

what is the answer in blank? I think the loop structure for the top blank is an intron. I think RNA is the answer for the bottom blank, but it is cDNA, so it can't be RNA. I cannot figure out ...
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1answer
111 views

Why do bacteria need messenger RNA?

Why do bacteria need mRNA? Isn't the DNA free floating without nuclear membrane so why doesn't the tRNA read the code directly off of the split DNA strands? (ofcourse after helicase splits them). ...
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1answer
35 views

Why isn't the RNA in bacteria always split up and replicating?

Isn't helicase always free floating in bacterial cells, and the DNA without a nuclear membrane and uncoiled and freefloating and so why doesn't the helicase keep breaking the double helix of DNA? ...
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0answers
16 views

Amputation of part of the cytoplasm of the amoeba? [closed]

We ampute a part of the cytoplasm of the amoeba many times and we observe that amoeba is not divided This experience allows to deduce the cause of the division of amoeba Do that have relation with ...
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2answers
788 views

What is the instructional language of DNA?

DNA carries most of the genetic instructions used in the development, functioning and reproduction of all known living organisms and many viruses (Wikipedia). Is it already know how ATCG's ...
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1answer
32 views

How DNA programs the first cell in womb into a human [closed]

Sorry if you see me silly. I am just a programmer happens to be curious about biology... So far I understand how DNA make protein, how cell divides, how one composed of cells->tissues-> organs. ...
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3answers
122 views

Are non-coding RNAs introns?

I am slightly confused as to what part of the genome codes for non-coding RNAs. Is it the introns? This would make sense to me as to why they are not transcribed as the introns are not transcribed. Or ...
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1answer
39 views

In DNA sequencing, is “mate pairs” synonymous with “paired ends”? If not, how do they differ?

By just looking at Roach et al's paper I get the impression that they are the same thing, and the Wikipedia URL for the former is a redirect to the latter. However, I suspect they are not exactly the ...
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2answers
52 views

Prader-Willi Syndrome and Angelman Syndrome?

On the website http://www.whatisepigenetics.com/fundamentals/2/ it states that the imprint disorders Prader-Willi syndrome and Angelman syndrome, display an abnormal phenotype as a result of the ...
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1answer
43 views

Difference between PCR for linear template and a plasmid?

I believe PCR can be conducted both on a linear template and a plasmid, and I was wondering how these procedures differ in what enzymes are used, how the enzymes work on the template, primers used ...
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1answer
25 views

why dna polymerase 3 requires a primer for replication [duplicate]

Why DNA polymerase 3 needs a primer to star replication.And whats happens when there is no AUG sequence on entire DNA.
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1answer
42 views

Why do you need primers in PCR? [duplicate]

I have read that DNA polymerase requires a primer to bind to the DNA, but I am confused as to why this is the case. When DNA undergoes replication in the cell, there are no primers in the nucleus so ...
3
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1answer
90 views

How to perform a DNA structural alignment in pymol

How can I "fit" two DNA structures having different nucleotide sequences in pymol? I would like to use the structure of a DNA binding protein in pdb (1h9t), which is bound to DNA in the pdb file, ...
5
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1answer
66 views

How do mutations actually occur?

DNA replication seems so mechanical- the DNA polymerase just running along the template strand. I just don't understand how mutations can arise. When it comes to substitutions, I get that a wrong ...
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51 views

Getting PCR amplification at annealing higher than Tm!

I am amplifying a gene where in a gradient pcr i am getting amplification at an annealing temperature about 5 degrees (67) higher than Tm (62.5)? What is wrong here? Also, I am getting a very strong ...