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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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 ...
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186 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 ...
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200 views

Mitotic crossover happens in G1?

I was reading this article in wikipedia and came across this : It has been suggested that recombination takes place during G1, when the DNA is in its 2-strand phase, and replicated during DNA ...
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55 views

Nucleosome wrapping direction

Does anyone know which direction the nucleosomes are wrapped? I wonder: Relative to the B-DNA double helix twist direction (right-hand) Relative to the neighbor nucleosomes. Do they alternate to ...
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24 views

Inter-codon mutations statistical analysis

I am looking for a statistical approach to inter-codon mutations. For example a 64*64 (64*63 actually) table, that contain the possibility of mutation from one codon to another codon (CCA to CAA or ...
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74 views

RNA polymerase question

In this question we are examining a bacterial RNA polymerase that elongates at 20 codons per second. Question 1: How long will this RNA polymerase take to transcribe the Lac Z gene at 3510 base pairs? ...
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2answers
189 views

Do changes in an organism's cell modify the genetic information it uses for reproduction?

What I'm actually interested about is whether a modification in one cell during the life of an asexually reproducing organism affects its genetic information? Which cell's genetic information is used ...
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128 views

DNA-DNA cross-linking with formaldehyde?

The 3C (chromosome conformation capture) technology for studying chromatin 3D organization starts by a cross-linking step using formaldehyde to find segments of DNA interacting. In my understanding ...
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1answer
39 views

Are both (partial) copies of DNA transcribed in S and G2 phases of cell cycle?

For a little less than half the cell cycle, a significant number of genes are represented twice (just before dividing). Does the cell differentiate between these DNA in any way or are transcription ...
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2answers
622 views

Do transcription factors bind to both strands of DNA?

Do transcription factors (or generally proteins) bind to only single strand of DNA or both strands? Since it can have non covalent bonds to both strands in theory. I would like to know the mechanism. ...
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2answers
46 views

Can someone link me to resources on the efficiency of sticky end ligation?

I really would like to know if sticky end ligation could potentially be performed with very high efficiency, and which factors influence that. However, I can't find any papers on the subject, even ...
3
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1answer
122 views

How would you affect bulk DNA gene therapy for a human?

Let's imagine that we understood DNA programming and our genome very well and realized that there were some significant flaws (we die, we need sleep, etc.) And let's imagine that we understand how to ...
7
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82 views

Do DNA repressors exist?

I know about enhancers and the mechanism that lead them to increase the gene expression of their targets but I was wondering if similarly DNA repressors exist. I know about protein repressors but I am ...
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87 views

Questions on DNA damage

I'm not strong in biology, so bear with me on this: I've been reading that as we age, our DNA is damaged by internal (e.g. errors during replication) and external (e.g. sun damage or radiation) ...
4
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1answer
98 views

Is there a DNA analogue to ribozymes? [duplicate]

If not, is it impossible for DNA to have enzymatic activity?
4
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1answer
115 views

DNA sequencing problem

First off, let me start by outlining the problem: Your laboratory has established a technique for examining DNA replication in a cellular extract. To the cellular protein extract, you add ...
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1answer
457 views

What are microRNA, siRNA and antisense RNA?

From what I understand, microRNA binds to proteins which can cut certain mRNA strands do that this protein is not synthesised. This seems like gene silencing to me, however I have also come across the ...
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1answer
64 views

Can life forms exist from simple structures not made of the four bases? [closed]

I understand that all life forms on the planet are made from adenine, gauatine, cytosine and thymine, which chemically joined together to form RNA or DNA (correct me if I'm wrong). This goes on to ...
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3answers
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DNA is charged negative. Where is all the positive charge in my body?

DNA is charged negative because of its phosphate backbone. Since charges need to be balanced (so that there are no charges building up somewhere), what is the positive charge which neutralizes this ...
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5answers
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Does DNA have the equivalent of IF-statements, WHILE loops, or function calls? How about GOTO?

Does DNA have anything like IF-statements, GOTO-jumps, or WHILE loops? In software development, these constructs have the following functions: IF-statements: An IF statement executes the code in a ...
2
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1answer
563 views

Can DNA & RNA be considered as nature's programming language?

The final frontier of Biological Sciences could be considered understanding the effects of variation in the DNA (and RNA). If after fertilization the DNA of the zygote could be genetically ...
2
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1answer
31 views

What mechanisms exist for the excision of specific sequences from DNA?

I already know about recombinases (specifically excisionases), but was wondering if there were other mechanisms present.
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163 views

can the face of a person be accurately predicted from DNA information? [duplicate]

3/05/creepy-or-cool-portraits-derived-from-the-dna-in-hair-and-gum-found-in-public-places/?utm_source=plus.google.com&utm_medium=socialmedia&utm_campaign=20130503&utm_content=collageartdna ...
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3answers
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Why do eukaryotic organisms have introns in their DNA?

We touched on introns and exons in my bio class, but unfortunately we didn't really talk about why Eukaryotes have introns. It would seem they would have to have some purpose since prokaryotes do not ...
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Nutritious protein substance for vitamin enhanced crop?

I am not a bio or science major, but we have a subject, like an elective on biotechnology and we were tasked to think of a product that hasn't been invented yet. My groupmates and I thought of a ...
4
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1answer
863 views

Why AZT is selective towards HIV and doesn't impair human DNA replication?

I've found this article, which is a very old one (from the time when nucleoside analogs where researched as a possible way to prevent replication of virus genetic material, before the HIV epidemics). ...
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Why does high pH result in the denaturation of DNA?

In the Southern blot method, for example, a solution of NaOH is used to denature the DNA in the sample. I find this counterintuitive since I expected that $\text{Na}^+$ cations would neutralize the ...
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Why is it that heterozygous loci appear as two separate bands during gel electrophoresis while homozygous loci appear as one band?

Is it because heterozygotes have a greater base pair length? (And if they do, why is that?) Or is it because recessive alleles are moving slower than the dominant alleles in the gel?
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248 views

How does the size of insert affects the rate of Homologous Recombination in yeast?

When performing genetic knockouts in yeast using homologous recombination to replace a target gene sequence via a vector DNA, does the region between the flanking regions in the vector have to be the ...
2
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0answers
34 views

Link between macro lncRNA and DNA looping

I was wondering if anybody knows some publication about macro lncRNA (very long unspliced RNAs) or more generally a transcribed RNA that may lead to cis-DNA looping of genomic regions overlapped by ...
3
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1answer
38 views

DNA replacement: new species

This is a hypothetical question What would happen if the DNA of a prokaryote was replaced with the one of a prokaryote of another species, would the cell structures change and adapt to the new DNA ...
3
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1answer
2k views

Pros/cons: linear vs. circular DNA [duplicate]

Why did Eukaryotes evolve to have linear DNA and not circular like Prokaryotes? What are the pros and/or cons?
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1answer
55 views

Core architecture of the body encoding [closed]

First of all, I am not a biology guy; I am in Computer Science. But, I have a strong interest in all the mysteries of nature, from universe to human body. So, I want to ask a question related to ...
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What is biological dark matter?

I recently stumbled upon the Biological Dark Matter wiki page. Its pretty light on details, but it appears to be genetic material found in humans that doesn't fall into currently classifications. ...
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1answer
193 views

G>T transversion VS. T>G transversion?

So I'm reading about how mutations in DNA can be caused by oxidative damage. An example of a product of oxidative damage is given: 8-oxo-7-hydrodeoxyguanosine My textbook says that this product ...
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2answers
99 views

DNA barcoding and real-time PCR

I recently read an article on how DNA barcoding was used to identify species present in health products. I also read an article about how Real-Time PCR was used to identify meat species in meat ...
2
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1answer
92 views

Has DNA communication/interaction at a distance been empirically demonstrated?

I recently had a discussion with a statistician in my school about memory. Among other things, he told me that it has been experimentally demonstrated that when one extracts DNA from any organism and ...
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2answers
57 views

How do I find a protein from this DNA sequence?

I have a DNA sequence from a sequencer. How can I determine what protein is it? I tried some translator but it didn't help. What protein is this and how can I determine it? The sequence: ...
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What is it about the housekeeping genes that makes them almost immune to gene regulation?

When it comes to eukaryotes, including ourselves, we have all different kinds of specialized cells and tissues that are so different, yet originally all came from the same single cell. And apparently ...
9
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1answer
770 views

How are we able to find the specific sites at which DNA binding proteins bind?

We know that some DNA binding proteins are site specific, that is they recognise and bind to a specific nucleotide sequence. My question is how can we precisely tell at which sites they bind? Is it ...
6
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SNPs and locations

I am new to reading raw DNA. When comparing two people's raw data, why does one person have a different SNP than the other, at the same location, on specific chromosome? But on a different chromosome ...
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1answer
194 views

Plasmid in the nucleus and gene expression

If we insert a plasmid into a human nucleus that contains exact copy of gene and all relevant promoters to produce some human protein, will the cell create functional protein from that plasmid only ...
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1answer
307 views

Can genetic engineering be performed without a laboratory setting? [closed]

I'm becoming more interested in genetic engineering as I learn more about it, and it's becoming more and more apparent that there's very few resources on genetic engineering at home. A similar ...
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0answers
84 views

Transfect Mammalian Cells with Single Stranded DNA?

Agrobacteria can deliver parts of their DNA to plant cells as T-DNA, transfer DNA. This DNA is delivered as a single strand and can be integrated into the plant genome or can be converted to a double ...
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1answer
59 views

Repair wrong DNA pair after ending replication?

If there are wrong DNA pair, for example A=G, is there mechanism that could repair such things - after the replication was finished? Or it happens only during replication?
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1answer
38 views

The damage of cancer cells

I read about the molecular biology of cancer, and I have a mess on my head and a lot of questions.. . My primary question is- The damage of the cancer cells is in the dna sequence or in the gene ...
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1answer
71 views

Could we engineer humans to behave like insects? [closed]

First off, though complex, I'm assuming insects are at an earlier evolutionary stage than humans. That being said, could humans be genetically engineered to behave like insects? I'm not talking about ...
8
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1answer
2k views

why is DNA antiparallel? Can it be parallel?

My biology textbook mentions that DNA is antiparallel and it got me wondering... Can DNA be parallel? What would happen if it was parallel? could DNA still replicate right?
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Do apes and humans share 99% of DNA or 99% of genes? What is the difference?

I made an answer on the Scifi.SE that can be read here. It is about how the characters in the story Jurassic Park might have gotten DNA for all the species shown. In my answer, I said this: Apes ...