Questions tagged [dna]

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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Can I use a basic compound microscope to analyze the ploidy of plant chromosomes?

So, I'm not really any kind of trained botanist. But I do have two things: some dandelion seeds from France, and, collecting dust in my garage along with related accessories, this thing. Normally, ...
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Is vaccination futile or not [on hold]

Are measles and such obscure, subjective diseases? Are there any serious vaccines for other diseases? Is Vaccination backed by evidence? Or I am sure.
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Can something cause both breaks and cross-links in DNA?

A double strand break in DNA is exactly that: the strands of DNA are severed. A cross-linkage occurs when something forms a covalent bond between two nucleotides in DNA. However, is it possible for ...
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Explain to a layperson how cigarettes smoke might cause cancer

I have a very intelligent friend who is a light smoker, and also a Biology layperson. I wondered whether understanding exactly how cigarettes smoke can cause cancer, might encourage him to smoke less ...
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Is it possible to fuse DNA from two sperms into one sperm?

Is it possible to fuse the DNA of two genetically different sperms into one singular sperm? In theory, half of the number of chromosomes in a normal sperm would come from one sperm and the other half ...
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Replacing, instead of repairing, DNA

I've been doing some light reading on DNA damage theory of aging. One of the main ideas from that theory that I got is that the accumulation of damage in our DNA is one of the biggest causes of why we ...
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Why is double stranded DNA considered to be one molecule? [duplicate]

Wikipedia, for example, refers to DNA as "a" molecule, not two separate molecules forming a double-helix structure. Isn't this technically incorrect? There are two separate polynucleotide strands (...
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366 views

Do telomeres appear at just one end of the chromosome?

I have just studied DNA Replication for my Biology Class and I have this question that leaves me stuck, though I have tried to figure it out myself. During telomere replication, I am aware Telomerase ...
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How would two SNPs interact to affect CYP3A5 gene activity?

If someone has a non-functional rs41303343(T;T) SNP, yet that individual also possess the partially functional rs776746(A;G) SNP, is their CYP3A5 genotype functional or nonfunctional? In other words, ...
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What is the fibre axis in the Watson and Crick paper?

I was reading Watson and Crick’s original article on DNA structure in Nature 171, 737–738 (1953). The accompanying diagram (shown below) has something called the “fibre axis” going through the DNA. ...
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Klenow amplification

Am I correct in thinking that in a standard probe synthesis reaction where primer/template are heated up and then cooled down for Klenow to extend, the theoretical maximum amplification is doubling of ...
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Left and Right Handedness

Today I found out that the gene for being Left-handed is dominant while Right-handed is recessive. I personally am left handed and so is my father. My mothers father is also left handed and I was ...
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Number of DNA strands per chromosome

As I was reading Griffith's Introduction to genetic analysis this evidence was provided for single DNA makes single chromosome. Eventually geneticists demonstrated directly that certain chromosomes ...
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What is the difference between DNA vs RNA Editing in the context of gene therapy?

As a someone with beginner knowledge on biology, I have come across the terms "RNA editing". Take this paper for example : RNA Editing with CRISPR-Cas13 From my understanding, DNA -> RNA -> Proteins ...
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Do all restriction enzymes have palindromic recognition sites?

I am trying to find out the requirements for a segment of DNA to be the recognition site of a restriction enzyme. Acording to the article on Restriction Enzymes in Wikipedia, "many of them" (...
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Can radiation exposure cause cancer later in life even if no traces of radioactive material are present in the body anymore?

I had a long-lasting debate with a friend of mine about the Fukushima incident. The question that we tried to solve was if radiation or toxin exposure can cause cancer later in life even if no ...
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How do primers anneal to ssDNA?

In a PCR type protocol, the high temperature stage of the cycle will cause dsDNA to denature, as well as any annealed primers. At the lower temperature the denatured dsDNA will remain denatured. As ...
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What do lower case nucleotides mean in this gene sequence?

The following table (image linked below) shows promoter sequences recognized by different sigma factors. The sequence given for, e.g. sigma B is "GTTTaa"; why are the "a"s lowercase? Thanks! ![From "...
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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 ...
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What did Francis Crick and James Watson discover that Rosalind Franklin didn't?

I've recently been introduced to the history of DNA research from Miescher to Franklin, Crick, and Watson, and I've found that Franklin had figured out a great many number of things out that Crick and ...
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Genes of the electron transport chain

Where are the genes of proteins that make the electron transport chain of mitochondria?(are they in in the nucleus or they are in the dna of the mitochondria itself?) Thanks for this answering system ...
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How to convert enrichment/depletion to frequency for comparing deep sequencing to sequence profile?

I have two datasets, from different sources, that I need to compare. The first set is deep sequencing results of a directed evolution experiment, where I have the naive library and selected library ...
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Is solving cancer required in order to avoid aging?

When the telomerase enzyme is not active the telomere shortens every time the cell duplicates leading to a reproductive limit (Hayflicks limit). On one hand this is a believed reason for aging. On the ...
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Can DNA be flattened?

DNA is always shaped like a double helix. But could you flatten the double helix (which is essentially just a twisted ladder) and would DNA still be able to duplicate and control cells?
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Is it possible to Clone a Dinosaur with a full strand of their DNA? [duplicate]

If you have a full strand of Dinosaur DNA would it be possible to make it living and hatch a dinosaur? Or would it be a failure? Could you use a bird or alligator, for replacein
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56 views

Where can I find DNA decryption research? [closed]

What is the name of the science that studies the mathematics of DNA? Where can I learn about maths, statistics, types of code, numbers, patterns and graphs for genes and information found in DNA?
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What is the expected amount of DNA shared by first cousins and the people between them in a family tree?

What is the expected amount of DNA that is shared by all of the people between first cousins, including the first cousins, in a family tree?
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Need help to determine % difference between DNA-strand from two different haplotypes. Known nucleotide diversity and more

Backround: 229 DNA sequences 493 bp in length Haplotype diversity: 0.9956 Average number of nucleotide differences: 12.50544 Polymorphic sites: 145 Nucleotide diversity: 0.02426 Is it possible ...
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Design rules for DNA linkers

I want to use double stranded DNA linkers to physically bind two "things" together, by grafting ssDNA on each one of them and using DNA hybridization as the locking mechanism. I do not expect the ...
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282 views

Heat shock vs electroporation

I've been transforming E. coli via heat shock in order to insert oligonucleotides (around 50 nt); however, none of my experiments have given positive results so far. I begin to question the efficiency ...
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Is newly produced sperm healthy if there was previous DNA damage?

I read that sperm cannot repair DNA damage. So does this mean that if your sperm has DNA damage, then all of your sperm (whether present or future) has DNA damage? Or does it just mean that the ...
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36 views

Will DNA nanostructures be useful for medical applications?

There is a lot of work being done on developing small nanomechanical structures and even small nanomechanical actuators built with DNA. I have heard researchers motivate this research with claims ...
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Phenotypes caused by mutations in mitochondrial DNA?

Will mutations in mitochondrial DNA necessarily affect phenotypes? I have some cursory knowledge of serial endosymbiotic cell theory, and find it difficult to consider that the DNA of the former ...
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56 views

Is DNA from more parents (than two) better for the fitness of the offspring?

I'm designing a system (a computer system actually) and (a whole while ago) I spoke with a friend about it and he had this opinion: If you combine DNA of more parents (than 2) it's better for the ...
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PCR in different cell line

I developed a PCR cycle to amplify a 5.5 kb genomic DNA region in HEK cell line. When I tried to use the same protocol in A375 cell line I had no results but only smear. Can you help me? Thanks in ...
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Why replication collapse but not stall leads to DNA break?

I have been looking into the concept of replication dynamics and was wondering why collapsing but not stalling leads to a DNA break.
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Is DNA actually like source code repository?

So after reading articles like "People Use Just 8.2% of Their DNA" etc., and thinking a bit... I got this idea: What if DNA is actually like a software source code repository? You know, it has "...
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probability of hairpin vs self-dimer formation?

I have a linear ssDNA oligo that is designed such that the ends are complementary, and conducive to hairpin formation (see attached figure). My question is, which has a higher likelihood of formation, ...
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How close genetically is the most human-like chimpanzee to the most chimp-like human?

I understand that: Chimpanzees are the closest species to humans genetically. Only 1%-6% of their genes are different. Within any species there is genetic diversity, i.e. no two individuals have the ...
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Calculating Possible Combinations of Bases in a DNA Strand of a Given Length

In my Biology class we were asked this question: This DNA strand consists of eight pairs of nitrogenous bases. How many different sequences of eight bases can you make? Explain how you found your ...
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DNA replication - how many times and when does it occur?

I’m currently learning about DNA replication in both prokaryotic and eukaryotic cells. And my lecturer has mentioned that replication is a once in a lifetime activity. And I’m not sure what this is ...
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How do introns code for proteins? [duplicate]

The reason I am asking this is because my textbook states that: Some introns may themselves encode proteins, and some may become short non-coding lengths of RNA involved in gene regulation. Some ...
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Calculate a global dN dS ratio for the all tree

I'm using the codeml application with the python package ete3 in order to calculate the dN/dS ratio of my trees, but it appears that there is no possibility to calculate a such ratio for all the three....
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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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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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What happens after the purification step in Hi-C sequencing?

I am a statistician reading an article on Hi-C, and I am trying to better understand one of the steps in the DNA isolation and sequencing process. Since I'm a statistician, please try to avoid too ...
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How is it possible for phosphate to form two ester bonds in DNA replication?

I understand that in phosphodiester bond formation, two hydroxl groups on the phosphate molecule bind to the 3' and 5' OH groups on two independent pentose sugars. This is a condensation reaction, so ...
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Is there a biological mechanism for evolution encoded into our DNA?

Throughout high school, I remember learning about Darwin's theory of evolution as if it were near-fact. But something always seemed wrong about the ideas presented. Survival of the fittest Random ...
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Possible combinations in the Meiosis' Telophase 1

As you might already know Meiosis is the process in eukaryotic, sexually-reproducing animals that reduces the number of chromosomes in a cell before reproduction $^{[1]}$ One of the reasons why ...
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How does the nucleophilic attack in DNA replication occur?

Hi there, I am confused about how the nucleophilic attack occurs in DNA replication.I watched this video from a biology professor (https://www.youtube.com/watch?v=y4hKibS2fAo) I watched this video ...