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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What determines the number of chromosomes an organism carries?

This is an extension of this question about What limits chromosomal length?. I am wondering what could be the specific reasons behind the number of chromosomes an organism carries. In other words, ...
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3answers
191 views

Immortality Gene? Really? [closed]

I read somewhere in the internet and wondered if human genes have deactivated immortality genes locked somewhere in the DNA strand. Is this statement true? What does it mean for human lifespan?
0
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1answer
175 views

Which pair of primers should be used to amplify the ORF in PCR? [closed]

So I want to choose the correct set of pair of primers to amplify the ORF of the gene that corresponds to amino acids in a protein. The start and stop codons are underlined. (I know that these need to ...
10
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4answers
1k views

“Same” DNA vs genes

It is often cited that humans share 99% (or 98%) of their DNA with chimpanzees. On the other hand it is stated that siblings share only half of their genes. What (if any) is the difference between ...
5
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1answer
700 views

What does it mean to “map the human genome”

I know some elementary chemistry and biology. I also think I know what a gene is (it's a sequence of DNA which encodes a particular protein). I also know that on a chromosome there are sections of DNA ...
11
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1answer
3k views

Are human chromosomes connected or separate molecules?

Do the 46 human chromosomes form a single unbroken DNA helix? Or is it rather that a human's genome consists of 46 disconnected helices? If it is the former, does the common numbering scheme for ...
14
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3answers
1k views

Is the size of the genome across species roughly the same?

Chromosome number differs across species. Is the amount of DNA comparable between organisms, just being split into smaller chunks in those species with more chromosomes? Or do species have different ...
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0answers
25 views

Is it possible that the DNA of an individual changes significantly over a period? [duplicate]

Is it possible that the DNA of an individual changes significantly over a period ?
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0answers
161 views

How stable is linear DNA transfected in eukaryotic cells?

I would like to know, with references from the literature, what is the half life of a linear dsDNA transfected in a mammalian cells. For example, if I transfect human cells with a PCR product (500-...
2
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1answer
111 views

Consequence of Plants as Incomplete Protein Source

Some years ago, in a 1000~ level biology course we learned that the DNA essentially encodes formulas for creating proteins from amino acids. While the human body can synthesize many many amino acids, ...
0
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1answer
73 views

X-recessive disorder pedigree confusing me

This is a pedigree of a family in which bleeder disease, an x-recessive disease, is present. I am asked which marker, A or B, the disease is linked to. I've asked about this type of problem before: X-...
1
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1answer
70 views

Dynamic mutation and huntington's

I read that Huntington's is a disorder caused by dynamic mutations in the DNA, which means that a triplet sequence of DNA changes from generation to generation. Say we have the sequence ATGATGATGATG. ...
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1answer
54 views

Where to find gene manipulation video (or photos)

I hope Im not asking a dumb question! Where can i find video of gene manipulation in action under microscope? Like extracting a gene from a cell, fixing gene mutations, putting the gene in a vector, ...
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3answers
279 views

What is a genetic marker?

In DNA sequencing and analysis, what is a genetic marker? I've heard that microsatellites are genetic markers? Those are repetitive strands of bases such as GCAGCAGCAGCA etc. Why are they markers and ...
0
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2answers
113 views

Chromosomal translocation notation

A reciprocal translocation is denoted for example: t(4;12)(q32;q24) indicating that q32 on chromosome 4 being swapped with q24 on chromosome 12 if I understand this correctly. My question is: How do ...
0
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1answer
46 views

X-recessive disorders and genetic markers

Please observe the following pedigree of a family with a x-recessive disease (bleeder disease). The A's are genetic markers so close to the disease gene that recombination is negligible. I ...
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1answer
110 views

Pedigree problem and type of inheritance [closed]

Please observe the following pedigree and come up with a conclusion as to which type of inheritance is most likely Now it should be obvious that it's either autosomal dominant or autosomal ...
3
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1answer
47 views

Gene frequency problem

1/330 of white people in south Africa have a disease called Porphyri. What is the frequency of the gene if it is inherited autosomal recessive? This one I understand. The genotype frequency is $q^2 =...
3
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1answer
86 views

Walk me through microsatellite markers and PCR

Three polymorph microsatellite markers are used to try and narrow down the location of a disease locus, with the use of PCR with 2 flanks on each side of the actual polymorphic area. The PCR product ...
4
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1answer
109 views

Bayes theorem for mutations

MEN 2A is a dominant inherited disease caused by a mutation in the RET proto-oncogene. The probability of being sick when you have the mutation of the RET proto-oncogene varies with age and is assumed ...
2
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1answer
124 views

From a computer science perspective, how is DNA compared for various purposes?

I am very interested in privacy preserving technolgies, such as Microsoft PINQ and would like to see if this is applicable to DNA comparison. Given that I don't have a background in biology, I ...
1
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1answer
160 views

DNA extraction methods for hair?

TLDR: Can anyone state a extraction and isolation method(s) for genomic DNA for hair that will be used for PCR, in detail is preferable since I am a novice. I tried googling for DNA extraction ...
2
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0answers
82 views

CRISPR-Cas Systems

In the context of the bacterial systems (not the gene editing tool), I was wondering what happens to the foreign DNA after the Cas proteins have created a new spacer. It is really not clear to me, ...
5
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1answer
434 views

Does crude oil or kerogen contain ancient DNA?

According to wikipedia by the formation of oil there are a lot of organic materials present including DNA. Is it possible that this DNA is conserved somehow for millions of years?
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0answers
111 views

Can these “Promega Wizard genomic DNA Purification kit” be used for samples not stated directly?

I am not sure if this is a duplicate of my previous question, it is somewhat related, so sorry if I misunderstood. The question is, can i use the above kit for samples like hair, fingernails, etc? ...
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2answers
5k 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 ...
2
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1answer
53 views

Help reading gene markers

I'm sorry if "gene markers" is not the correct word. An edit could be appreciated but I don't study in an English speaking country unfortunately. Question overview: In a family, there is a genetic, ...
6
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1answer
61 views

Why aren't genetic triplets roughly evenly found in DNA?

Sorry, the page I linked to is huge and you'll need to do a text search for "CG" to find the part I'm talking about. I found a graph on this page (http://www.oftenpaper.net/sierpinski.htm) showing ...
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2answers
1k views

What is the difference between sequence, reads, and contigs of genetic material?

Can someone explain the differences between sequence, reads, and contigs of genetic material such as DNA, if possible with an example? I am new to bioinformatics, and I have not found any conclusive ...
2
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0answers
87 views

Can DNA test of my grandparent's brother reveal my heritage from that branch of the family?

I'm thinking about doing that DNA test on all my grandparents to know where their genes come from. They are getting very old and I don't want to let the opportunity pass to gather more knowledge about ...
7
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1answer
242 views

Double stranded nucleic acids are more 'durable' than single stranded nucleic acids?

I'm struggling with a question I've been asked. "Why is double stranded genetic material more 'durable' than single stranded one?" I know that double stranded genetic material is more stable due to ...
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3answers
85 views

DIY storing family DNAs' samples for future uses (eg medical)

I have a question I could not get an understandable reply from Google and I am no expert in the matter, so my plead to you is if you could give me practical and relatively easy to follow advice. With ...
2
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1answer
107 views

Mitochondrial D-Loop

I know that the D-loop is a DNA complex in which the strands of double helix DNA molecule are separated for a stretch and held apart by a third strand of DNA. Usually, this third strand has a base ...
41
votes
4answers
3k views

What exactly are computers used for in DNA sequencing?

I've thoroughly read the Wikipedia article on DNA sequencing and can't get one thing. There's some hardcore chemistry involved in the process that somehow splits the DNA and then isolates its parts. ...
4
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1answer
86 views

Why doesn't mitochondrial DNA accumulate damage over successive generations?

From what I recall, mitochondrial DNA is very susceptible to damage from oxidative stress because it is a site where free radicals are generated and their DNA isn't packed into chromatin like nucleic ...
0
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1answer
184 views

Does the DNA of a tadpole change after it becomes a frog?

Does the DNA of a tadpole change after it becomes a frog? In other words what changes take place as a tadpole becomes a frog, and does this metamorphosis affect the DNA in any way? I would appreciate ...
2
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2answers
1k views

How accurate does the alignment of molecules in DNA have to be?

We have learned that the same information is saved in the DNA in the same place. So when DNA splits and then connects again (during reproduction); how does it maintain the integrity of the information?...
2
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2answers
144 views

Help reading chromatogram

A genetic variation is found in this chromatogram: It says that the "reference sequence" is the top line and that I can use the general genetic code to find the reading frame. I can see that there ...
4
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1answer
2k views

Does DNA polymerase always go the same direction?

I read that mutations are more likely to occur on "the strand that DNA polymerase replicates discontinuously". Does DNA polymerase always go replicate the same strand discontinuously, and if so, how/...
3
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1answer
104 views

DNA length and annealing kinetics

I have a mixture plasmids and undesired short linear fragments that share the same sequences. During denaturation and annealing, I would like the plasmids to 'find each other' before annealing to the ...
12
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2answers
495 views

Are there differences in DNA between humans of today and humans from 2000 years ago?

Are there any significant differences in our genome compared to the genes of our ancestors from 1000-2000 years ago? And if there are significant differences, do they result in significant ...
0
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1answer
71 views

Simplest Biological Organism? [duplicate]

What is the simplest biological organism from which a DNA sample has been or could be obtained? Could the resulting DNA be processed and examined in such a way that the resulting information would ...
3
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1answer
42 views

Forensic genetics- why is mtDNA comparison sometimes better than nDNA comparison?

Why is (in forensic genetics) in some cases more appropriate comparison of nuclear DNA but in some other cases comparison of mitochondrial DNA? Is it because geneticists are sometimes unable to find ...
6
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1answer
74 views

“Enhancers” of enhancers?

I am looking for examples (if any) of genomic regions which regulates the activity of enhancers, either augmenting or reducing it. Essentially some kind of enhancers (or repressors) of enhancers to ...
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2answers
156 views

What's the proton concentration around a DNA helix?

Let's suppose the concentration of a 20-nt DNA strand is $10^{-4}$M and the solution does not contain any salt ions. In a solution with pH 7, $[H^+]=10^{-7}$M, on average each DNA has only 0.001 ...
3
votes
1answer
94 views

Is it possible to insert DNA without cutting the recognition site with CRISPR/Cas9?

We are looking for a way to insert DNA into a genome, but we would like to do it in a way that the recognition site stay intact to be able to add again DNA at the same location. Do you know if it is ...
6
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2answers
2k views

What conditions should I use for Gel Red staining?

What are the optimal staining conditions when using Gel Red? So far, since we have started using it, the gels ran in our lab have been of very poor quality. The bands are very blurred and often ...
6
votes
1answer
76 views

Why differentiated cells can't “undifferentiate” (under normal conditions)?

In a process called differentiation, the cells of the developing organism undergo huge changes, which result in cells, functioning "completely" differently. Two cells are considered to be of different ...
3
votes
1answer
235 views

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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Why are 3 nucleotides used as codons for amino-acid mapping in DNA?

DNA is made of 4 unique nucleotides. When coding for a protein, a sequence of 3 nucleotides is used to code for each amino acid. Why are codons 3 nucleotides in length? A related question can be ...