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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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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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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73 views

Write the haplotypes of the family

I'm doing old exam assignments to prepare for my finals on Monday and I've stumbled on one assignment that I'm not sure how to tackle. A family with 2 children is examined for cataracts using PCR ...
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49 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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2answers
203 views

What errors can occur during DNA replication?

When there is an error in copying DNA (a mutation), what exactly goes wrong? If G goes with C and A goes with T, I don't see how that part can mess up. Is the idea that when the double helix is ...
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42 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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83 views

Known ways to modify the genetic structure of the 13 loci used in CODIS

After reading the answer to Does our DNA change during our lives?, I was wondering if and how it would be possible to change the structure of the 13 loci that are used in the CODIS database, in such a ...
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1answer
39 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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1answer
128 views

In CRISPR bacteria, how does viral genomes get integrated into the spacers of CRISPR? Also, in its use, where does Cas9 cut the DNA?

I've been out of Biology for about a year polishing my programming skills. I know CRISPR/Cas9 allows targeted 'cutting' of DNA via RNA-guidance. Few questions regarding this. Regarding to its ...
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22 views

What are flagged primers? [closed]

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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The Uniqueness of DNA Paradox

How can everyone have unique iris and fingerprints? After a certain amount of human beings have lived on earth, wouldn't it be possible to exhaust all possible combinations? The same principle ...
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1answer
76 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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1answer
55 views

Expected dS/dN ratio for exome

I am trying to determine whether or not my sequencing data has more/less non-synonymous mutations than would be expected. My understanding is that there is some fixed ds/dn ratio for the human exome ...
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1answer
93 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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2answers
73 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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45 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 ...
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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?
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4answers
850 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
125 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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35 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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1answer
123 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
38 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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3answers
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Does a man contain all the genes needed to make a woman?

This question is brought on by a Sci Fi novel I am thinking about writing. The plot device involves a colonist in charge of building a population on a new planet who loses his supply of embryos and so ...
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1answer
70 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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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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1answer
189 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, ...
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2answers
831 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
39 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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2answers
180 views

Why can't this be 1st meiotic division non-disjunction as well?

The child has gotten 2 "sick" chromosomes from his dad and 1 healthy from his mom, leaving it with trisomy 13. I can see how this can happen in the second meiotic division of the father but I can ...
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210 views

Why does size decrease across the sequence of human chromosomes?

The following graph shows a decrease in the amount of base pairs per chromosome across the sequential set of human chromosomes: Is this because chromosomes were originally numbered by their size on ...
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1answer
48 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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1answer
89 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
33 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
81 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 ...
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1answer
92 views

Protocol to dilute DNA step ladder?

I need to run gels that are of not the "most" importance. So I do not want to waste alot of money on step ladder. How do I dilute DNA step ladder? Is there a general procedure, for I have tried ...
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1answer
6k views

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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1answer
2k views

Calculating number of amino acids in mRNA

Assuming there were 20 different amino acids and less than 40 types of different tRNAs found in this alien organism. How many amino acids would be found in the translational product of a ...
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1answer
49 views

Can DNA base pairs go through each other? [closed]

Consider the simplified version of the motion one DNA base pair held together by a hydrogen bond: Use u and v to denote the displacements of the bases from their equilibrium position along the ...
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1answer
103 views

Clarification on the “orientation” of chromosomal rearrangements

I need some clarifications on the concept of "orientation" in case of chromosomal rearrangements. Given a deletion event on a chromosome for example, is the resulting DNA at the breakpoint always in ...
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2answers
119 views

Alternatives to PCR

PCR uses cycles of heating and cooling to denature the strands, calling for special thermostable DNA polymerases. In a cell, during replication, Helicase unwinds the DNA without the requirement of ...
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1answer
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How many nucleotides are there in the LMO1?

Dr Maris at CHOP has linked the cause of high-risk neuroblastoma to a common SNP in LMO1. How many nucleotides are there in the LMO1 gene?
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3answers
109 views

Are missing limbs hereditary?

So with my basic understanding of biology, DNA can change over time. Does this mean that if one (or both) parents have something major missing (like a limb), the kid will come out without a limb? ...
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2answers
93 views

What would be the shortest and optimal method of extracting human cells for PCR? Is there a colony PCR like protocol for human cells?

I am trying to devise a quick method to extract genomic DNA from human cells for a PCR. I first collected cells by centrifuging saline mouthwash (0.9% NaCl) and extracted genomic DNA using kit ...
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22 views

Base Excision Repair and Nucleotide Excision Repair

What's the difference between BER and NER? I understand that BER removes the improper base, while NER removes the nucleotide (including the base). However, in BER, don't repair enzymes then remove ...
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31 views

What is the aqueous solution for DNA immobilization?

This paper Electric-field assisted immobilization and hybridization of DNA oligomers on thin-film microchips Which is talking about how the electric field improve the DNA immobilization process. ...
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What are the reasons which make intron detection uncertain?

Intron/exon sequence detection seems to involve statistical prediction which can at best deliver a guess (until experimentally confirmed) as to where the splice site is. What are the reasons why ...
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1answer
92 views

difference in genetic instuctions between male and female [duplicate]

I'm a computer science graduate so please bear with me the following computer program : mov ecx, -1 INC ecx consist of 2 instructions (mov,inc) each working on specific data , can genetics ...
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2answers
51 views

Do eukaryote cells contain DNA that isn't part of a chromosome or located in the mitochondria?

I specify eukaryote in the title, but I'm also interested if this question isn't applicable to eukaryote cells in general but is to humans. I was reading "RNA-seq: An assessment of technical ...
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1answer
46 views

Query from a ppt slide

I came across this slide: Now I haven't understood what the last two grey colored lines mean. Can't ORFS be of any size? What is overlapping frames here?
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Does common PCR amplify genes regardless of what cells / barriers they are in?

I have some understanding of how PCR testing works. What I have always been wondering: how can we be sure that a primer reacts with the targeted gene(s) regardless of where¹ the genes are inside a ...