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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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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Which organisms have introns?

From Wikipedia: For example, introns are extremely common within the nuclear genome of higher vertebrates (e.g. humans and mice), where protein-coding genes almost always contain multiple introns, ...
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How does “inheritance of methylation” of DNA and/or histones work?

What are the current models/ideas describing the mechanisms explaining inheritance of methylation on DNA resp. histone level? Is there evidance of this "setup" information being really ...
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934 views

Finding exons in DNA problem

My attempt: I looked for the TACs because I thought this would be AUG in mRNA and ultimately Methionine (the start codon). But apparently, that's not how you do this problem. Im confused because ...
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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 ...
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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) ...
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706 views

DNA content in plant seeds vs. fruit flesh

Is there a publication comparing DNA yield and/or PCR-amplifiability after extraction from fruit flesh (like apples, oranges, cherries etc) in comparison to seeds of the same fruits? I would prefer a ...
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637 views

Effect of single nucleotide deletion or insertion on primer annealing

How is primer annealing, and, consequently, PCR amplification affected by single nucleotide deletion or insertion inside the primer ? Imagine a primer like this: GCGTCATAAAGGGGACGTG (primer) and ...
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relative-rate of evolution

I am supposed to calculate the relative rate of evolution of two sequences (human and sheep) with a chicken serving as the outgroup. The sequences are pretty long, so I will just create a short ...
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Reference sequence for defining single nucleotide polymorphisms

Single nucleotide polymorphism (SNP) or genetic variation in general, by definition are relative to a reference sequence. When we talk about databases of SNP as in ("dbSNP—Database for Single ...
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238 views

Microarray data and analysis tools

Microarray has various uses, and to analyse the data a main function classification is used. There are many methods used to classify the data but what are the best and most frequently used methods? ...
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Telomerase in tetrahymena

In this amazing video, at 26:03 we see this image We now know that the telomerase contains a sequence complementary to the telomere sequence and so is able to do what it is capable of doing in this ...
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509 views

How much does the Hayflick limit/telomere length vary across taxa and within humans?

Since they seem to be quite connected, I'm curious if anyone knows of research comparing the Hayflick limit (and presumably by extension telomere length) between different taxa. I've heard the ...
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Why Only DNA can Contain Hereditary Material?

Well I'm well aware that it is proven that DNA contains genetic material via transformation and Hershey-Chase Experiment of T2 bacteriophage. Still I was wondering what is the reason only DNA ...
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What triggers DNA to produce proteins?

What is the trigger for DNA to produce proteins or RNA? I have found enough material to study the inner workings of the cell and DNA; but, I can't find an explanation of the mechanics the cell uses ...
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What is the meaning of the “d(…)2” notation when writing a DNA sequence?

When the sequence of a DNA oligo is written as d(CGCTAGCG)2 what is the meaning of the d(...)2? Why would it not simply be ...
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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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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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Difference between mice and rats

What is the actual biological difference between mice and rats? Are they actually the same thing with two different names depending on appearance (are they all mice for instance and we call the larger ...
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640 views

What are the major causes of mutations in DNA?

I know that point mutations can change the base sequence of a gene by altering a specific codon that codes for a particular amino acid. Are these mutations purely random events that occur when DNA is ...
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Why are urban birds still scared of humans?

I understand that animals are naturally scared of humans because we basically slaughtered every living thing we found in our way for millennia. How long does it take for them to genetically 'forget' ...
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High sequence similarity but start codon isn't methionine

I have noticed in a particular genome sequence of a prokaryote that various regions in a sequence share similarity which is high(>80%) with known proteins. However, the start is not a methionine. Is ...
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More entropy: Atom or Macromolecule? [closed]

A question that appeared on my last exam was : Which of the following has greater entropy A) An atom B) A macromolecule The question doesn't specify anything else(i.e. type/size of atom or ...
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Is there variation of AT/CG ratio along species?

Chargaff's rules say that the number of Adenine of the number of Thymine in a genome are equal (nA=nT) and similarly nC=nG. This makes obvious sense knowing that C binds to G and A to T. But what ...
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Separating DNA Fragments by Gel Electrophoresis. Are all the strands for one size the same?

My apologies if my question is too basic, and please point me to a more appropriate forum. I am reading the textbook "Essential Cell Biology" by Alberts et al, and am consulting other sources as ...
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What risk to DNA does long-term exposure to low-dose radiation pose?

A new study from MIT scientists suggests that long-term exposure to low-radiation poses no risk of DNA damage for mice (it is also important to note that mice are unusually susceptible to cancer). So ...
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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 ...
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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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216 views

How to measure quality and quantity of DNA?

I would like to mesure DNA. I quantify the concentration with Qubit fluorometer, but I would like to know also quality of DNA. I try BioAnalyzer (Agilent),but without success. Bioanalyzer measure DNA ...
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235 views

How to learn molecular biology through pubmed research articles?

Instead of using a textbook, is there an alternative curriculum, that simply lists a set of pubmed research articles for each topic covered in a typical undergrad molecular biology course? I am ...
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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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How much DNA of Albert Einstein is recoverable?

Since there seem to be five biological descendants of Albert Einstein, and the original chromosomes of him distributed among them ... Is it possible to recover enough DNA of an individual from his ...
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283 views

What is the most genetically simple organism except viruses?

What is the most genetically simple organism (except viruses) on this planet? By simple I mean the least number of genes.
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What is DNA binding domain? It is not clear what the domain means

I am confused about the term DNA binding domain. Does it mean that there are some parts of the DNA that tends to coil up? Does it happen because some proteins tend to stick around that area? Also it ...
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Self pairing in DNA

I know that ssRNA molecule can fold over itself (e.g. in t-RNA). Can DNA do the same? Is there any example of this in nature? Why is this phenomenon more common in RNA than in DNA?
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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 ...
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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 ...
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dsDNA translation

Since DNA is double stranded and each strand is complementary to the other, the codons on each strand will come out to be different after transcription(depending on the reading frame). Does this mean ...
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Question about Autosomal Recessive Alleles

I had a homework question that I could not figure out. It states: A woman has cystic fibrosis in her family and did not want to have a child that suffered from the disease. She and her spouse ...
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424 views

Can replication occur if DNA is methylated?

Can a methylated strand of DNA be replicated without removing methylation? Does it make any difference if the strand is methylated or not (during replication)?
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How are atoms in benzopyridines and benzopurines numbered?

I am well-aware of the numbering system used for the traditional bases, as seen below. My question is how are the atoms in the size-expanded bases seen in xDNA and xRNA numbered?
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Why does Taq polymerase add 3' adenine overhangs?

Is there a mechanism for the preference of Taq polymerase to add a non-templated 3' adenine (overhang) instead of other bases?
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191 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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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 ...
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How fallible are DNA paternity tests?

Is it possible to get either a false positive or a false negative from a DNA paternity test and what would be the likely mechanisms behind this? For example, is it possible that a father's DNA could ...
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The move from RNA to DNA and the necessity of reverse transcriptase

In this piece about giant viruses and the origin of life, in the context of the move from RNA world to DNA world, virologist Valerian Dolja states: In order to move from RNA to DNA, you need an ...
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Is there a way to measure the amount of bytes that are possible to encode in a DNA molecule?

When I saw a DNA molecule for the first time, it kinda reminded me of a hard drive. It consists of slots and there are some possible combinations for each slot; in the hard drive these possible ...
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How do the major and minor grooves in the DNA helix arise?

I understand that they arise due to the pairing of bases of two opposite stands and are sites through which important proteins needed for replication and transcription of DNA interact. But I don't get ...
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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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Are genes uniformly dispersed throughout the genome?

I think that telomeres and centromeres are regions with a very low gene content (= regions that contain few genes). To the exception of telomeres and centromeres, are genes uniformly distributed ...