A structural aberrancy in DNA, as opposed to a sequence change (mutation). Often caused by reactive species.

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Can cancer cells in the same person, organ, and origin have different DNA?

Is it possible for cells from the same tumor to have different genetic material, and if so, to what degree is it possible (how fast do they mutate) ?
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5k views

Difference between mutation and DNA damage

What is the strict difference between mutation and DNA damage? As far as I understand it, a mutation is an alteration in the genetic sequence, having "tricked" the repairing machinery and thus ...
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63 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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77 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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1k 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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85 views

How to safely conserve my current DNA methylation marks?

I read the Wikipedia article on DNA methylation Let's say I want to extract and then stock my current DNA methylation marks somewhere so that I can use it safely 20 years in the future for a medical ...
4
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1answer
178 views

How does NHEJ cause indels?

I was reading up on CRISPR-cas9 and how it works and I am having trouble wrapping my head around how NHEJ to repair the DSB can cause indels to occur. Shouldn't the NHEJ just stick the two strands of ...
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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) ...
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112 views

How do nicks in the DNA strand affect the success of Long Range PCR?

Long Range PCR using NEB Master Mix - Hot Start Taq was working fine for me (amplicon sizes of ~10kb) but stopped working all of a sudden. Is it possible that many freeze-thaw cycles on the DNA ...
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111 views

Is a single x-ray photon capable of doing enough damage to the DNA of a cell to kill that cell? [closed]

Ionizing radiation is damaging to DNA, but is there such a thing as a safe dose below which no DNA damage could occur? I'm not asking about a minimum safe dose overall, just whether or not there's an ...
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2answers
2k views

How does non-homologous end joining (NHEJ) work?

I was reading about non-homologous end joining (NHEJ) in my molecular biology of the gene textbook but the explanation provided in the text was rather vague to me, and I was not able to understand it ...
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2answers
276 views

How can we create a living dinosaur using DNA technology?

I'm wondering what would we need to do to create a living dinosaur using DNA technology? If it is not possible with current technology, will it ever be feasible? In the movie Jurassic Park, ...
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191 views

Stay young by reinserting own DNA from years ago?

As far as I know, the DNA sequence becomes shorter every time a cell divides. A shorter sequence results in information loss and aging characteristics. As a countermeasure, shouldn't one stay young ...
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1answer
310 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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0answers
26 views

transitional mutation, repair mechanism

I have read an answer to a question about dna repair during and after replication. But how is dna repaired if a deamination of of 5-methylcytosine happens? How does a repair mechanism identify which ...
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3answers
296 views

If everybody DNA is different then how blood can match even with matching blood group?

We know that everybody's DNA pattern is different in the world. Then how can ┬┤we transfer blood from one person to another person and this person can survive ?
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233 views

How does DNA damage cause ageing in yeast?

As I understand it, in yeast ageing there is daughter cell and mother cell. The daughter cell is has newly "fresh" DNA and mother cell dies after some counts of replication. What happens to the ...
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3answers
115 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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1answer
97 views

Is each generation getting older? [duplicate]

So we know that our sperm and egg cells get set aside relatively early so that they aren't going through unnecessary cell divisions and causing DNA damage or telomere shortening, but since each new ...
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2answers
57 views

RF Cautery DNA damage?

I'm concerned about the safety and mechanism of RF cautery. The frequency of the radio waves used is 4Mhz so normally there should not be any DNA damage BUT the thing you read everywhere is that only ...
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1answer
41 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
54 views

Are nucleotides at the ends of DNA stripped on aging?

I had the following understanding (now after reading a popular science article seeming wrong understanding): DNA in (regular) cells (in human and some other organisms) are protected by telomers. ...
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1answer
64 views

meaning of “usually greater than 200 base pairs”

From "Risks from GMOs due to Horizontal Gene Transfer", by Paul Keese: Homologous recombination. All cellular organisms have molecular functions dedicated to recognizing and recombining DNA ...
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1answer
36 views

Does vitamin C decrease after reacting with oxygen free radicals?

From the research that I have done, I know that antioxidants such as vitamin c donate electrons to oxygen free radicals and effectively neutralize them. They themselves do not become free radicals as ...
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1answer
59 views

tandem repeat sequence; causes of contraction and/or expansion question

Question: Which of the following events, occurring within a tandem repeat sequence, will cause an expansion or contraction of the array? A) Endoduplication B) homologous recombination C) ...
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1answer
165 views

Question about the DNA glycosylase enzyme assay/formamide gel loading buffer

Often for the DNA glycosylase enzyme assay we can see that the DNA glycosylase is incubated with oligonucleotide in 37C and then reaction is stopped by addition of formamide gel loading buffer (80% ...
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1answer
87 views

Do mitochondrial DNA have repair enzymes?

Mitochondria are considered endosymbionts originated from a prokaryote. So, do they have a DNA repair mechanism ?
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Do “old” or damaged organs leak out damaging substances? [closed]

I'm wondering whether "old" or damaged organs leak out some substances (like free radicals or others) that damage other organs. For example consider a 50 years old healthy person. Assume for the sake ...
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167 views

Which is the best way to fix and preserve comet assay slides before staining with Ethidium Bromide?

I want to use the method of Single Cell Gel Electrophoresis (comet assay). I have many samples, but I don't have the appropriate microscope. So I have to preserve my slides until the time comes for ...
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1answer
123 views

Does the second law of thermodynamics cause aging? [closed]

What is the current understanding as to why organisms age and die? In the following explanation on Ask an Engineer, entropy is not even considered (despite it being answered by an engineer). Unless ...
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0answers
27 views

Color of DNA, available absorption energy levels of DNA molecule, mutations

I have done a couple of DNA separations and observe that the clumped strands of DNA are white. Is that an artifact of the chemicals used in standard separations? Or is it indeed the case that the DNA ...
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0answers
32 views

How can my baby DNA be “brand new”? [duplicate]

If it is assumed that "over time, our body and our DNA get damaged until we can no longer function properly", how is it that if I make a baby at the age of 40 with a partner of the same age, our baby ...
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0answers
23 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

Components of DNA repair and DDR

Many of the molecules involved in DNA repair, specifically Homologous Recombination, do not have clear differentiation from DNA Damage Response Pathway. What is the best journal article that makes ...