The Stack Overflow podcast is back! Listen to an interview with our new CEO.

Questions tagged [dna-replication]

The biosynthetic process by which copies of a DNA molecule are made.

Filter by
Sorted by
Tagged with
1
vote
1answer
56 views

At which point does a cell switch its function? [closed]

In a multi cellular organisms there are many cells of different functions. How / when does a cell change its function compared to its parent? Is it done by influence of other cells after its has been ...
0
votes
1answer
39 views

The relationship between the shape of the bacterial DNA and the blocking of replication machinery

I was reading a course about tolemers when I arrived to this phrase : [...] The ends of a linear DNA molecule cannot be replicated by the cellular replication machinery (which may be one reason why ...
1
vote
2answers
67 views

Performing PCR on samples whose DNA concentration is nul

Is it vain to perform a PCR on samples whose DNA concentration was measured as nul by a NanoDrop?
0
votes
1answer
445 views

dNTP concentration for reverse transcription from RNA to cDNA

Does it affect the results if I use the half of dNTP amount in a reaction that it says in my protocol? I usually use 4 microlitres per reaction and this time I did a mistake and I used 2. The final ...
2
votes
1answer
125 views

Do mitochondria contain the genes to specify themselves?

My book says : "Mitochondria contain their own genetic material so when a cell divides, the mitochondria replicate themselves under the control of the nucleus." The book means that the mitochondria ...
2
votes
1answer
2k views

DNA replication: How many DNA polymerase molecules work in parallel?

Background research I am aware that DNA polymerase works in pairs, at least. This is to process both opposite stands of a given chromosome. The 3'-to-5' "leading strand", and 5'-to-3' "lagging strand"...
2
votes
1answer
2k views

Does DNA helicase or topoisomerase actually “unwind” DNA?

I am reading through my textbook (Genetics, Brooker 4th edition) and the summary it gives seems imprecise for the functionality of helicase and topoisomerase. The following is an exerpt: ...
0
votes
1answer
737 views

Why is there complementary base pairing for DNA?

Why is there complementary base pairing for DNA? Why can't A pair with C given that they can all form hydrogen bond?
2
votes
1answer
450 views

Role of dam methylase in bacteria

In bacteria, an enzyme called dam methylase (Deoxyadenosine methylase) methylates adenines (A) in the sequence GATC in the new strand formed after replication. What role does this methylation play? ...
-2
votes
2answers
14k views

If we add only 1 primer in PCR [closed]

What would happen if we add only one primer, say forward primer, to PCR? (Image Credits: Wikipedia) As it is clear from the image that we need both forward and reverse primers to get it working (...
0
votes
2answers
786 views

DNA replication in E.coli

What is the difference between replication and to divide? My A level bio book says that it takes 20 min for E.coli to divide and in next page it's written that E.coli completes replication within ...
2
votes
1answer
1k views

Number of Chromatids in G1

I know that in G1, the number of chromosomes is 23 pairs, so 46. I assumed there were 46 chromatids too. Why is the number of chromatids in G1 actually 0, not 46? Thanks.
3
votes
2answers
138 views

From an information perspective, are both strands of DNA necessary?

I am learning about the genetic code, replication, and transcription, and I have a question about whether or not both strands of DNA are really "necessary". In replication, at a high level, we are ...
1
vote
0answers
63 views

Does any specific property decide which DNA strand acts as leading strand template?

Of the two strands of DNA, the one that unwinds in the 3' to 5' direction constitutes the leading strand template, with the other strand of course acting as the lagging strand template. Is there any ...
1
vote
0answers
103 views

Does cancer cells come from same process as evolution? [duplicate]

Here is how I understand it: DNA replication is not 100% perfect and error can happen, this error can be good(evolution) or bad(cancer properties). But its not the only source of cancer cells - DNA ...
1
vote
1answer
3k views

How RNA primer on leading strand is removed during DNA replication and how the gap is filled? [closed]

Please can you explain me how the gap created by the removal of primer on 5'-3' leading strand is filled.
3
votes
1answer
667 views

Does DNA polymerase I require a $3^\prime$ end?

DNA polymerase III adds nucleotides in the $5^\prime \rightarrow 3^\prime$ direction because it can only add nucleotides to the $3^\prime$ end of the previous nucleotide. This is why it requires a ...
2
votes
1answer
927 views

How does the splicing enzyme recognize where to splice the introns?

When the DNA from the nucleus is transcribed to an mRNA, the mRNA is spliced by an enzyme before it goes outside through the nuclear pore. What is the name of this enzyme and how does it recognize ...
0
votes
2answers
346 views

“Prime” structure of DNA Double Helix: Confusion

In this video on DNA replication, the diagram shows the unwound DNA as still being anti-parallel, but the first diagram in this post on Biology SE shows that the individual strands are 5'____5' and 3'...
1
vote
1answer
1k views

The Semi-Conservative Model of DNA Replication: Question

My Campbell's Biology textbook contains the following diagram related to the semi-conservative model of DNA replication proposed by Watson and Crick. I have highlighted where my confusion arises in ...
4
votes
0answers
118 views

What would the resulting karyotype be if someone with Klinefelter syndrome fertilized an “empty” egg?

Endoreduplication: is a form of nuclear polyploidization that results in multiple, uniform copies of chromosomes. This process is common in plants and animals, especially in tissues with high ...
0
votes
1answer
696 views

How does RNA polymerase achieve higher processivity?

DNA polymerase uses a sliding clamp in order to replicate DNA. RNA polymerase does not require one. What allows RNA polymerase to hold on to DNA just like DNA polymerase?
2
votes
1answer
117 views

Why isn't the DNA in bacteria always split up and replicating?

Isn't helicase always free floating in bacterial cells, and the DNA without a nuclear membrane and uncoiled and freefloating and so why doesn't the helicase keep breaking the double helix of DNA? Also,...
0
votes
1answer
2k views

Difference between PCR for linear template and a plasmid?

I believe PCR can be conducted both on a linear template and a plasmid, and I was wondering how these procedures differ in what enzymes are used, how the enzymes work on the template, primers used etc....
1
vote
1answer
4k views

Why do you need primers in PCR? [duplicate]

I have read that DNA polymerase requires a primer to bind to the DNA, but I am confused as to why this is the case. When DNA undergoes replication in the cell, there are no primers in the nucleus. Why ...
5
votes
1answer
247 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 ...
13
votes
2answers
4k views

Why and how is DNA synthesis so much faster then RNA synthesis in bacteria?

DNA synthesis in E. coli is 20x faster than RNA synthesis at 1000nt/s vs 50nt/s. (Mirkin'05) I find that perplexing since DNA polymerization has better proofreading than the RNA variety, which ...
2
votes
2answers
550 views

Bacteria Replication

I learned this at a lecture, but somehow I have trouble in understanding this. It is said that the bacteria such as E.coli need 20 minutes to divide, but its chromosome require 40 minutes to multiply. ...
3
votes
1answer
672 views

Why do some bacteria have an asymmetric replication?

Our teacher said that Bacillus subtilis has an asymmetrical replication fork. I know that this happens only in some strain of the bacteria . She asked us to find an explication for this mechanism , ...
-5
votes
1answer
143 views

Two 20 million yr old fossils of Hummingbirds found "The amazing thing about the fossil is that it's essentially a modern hummingbird [closed]

does this only mean that the Hummingbird is perfect in creation and needs no change to survive? http://news.bbc.co.uk/2/hi/science/nature/3691169.stm
7
votes
1answer
466 views

Why doesn't telomerase activity cause DNA to get longer each time a cell undergoes DNA replication?

Telomerase extends the ends of the lagging strands in order for all of DNA to be be copied. Doesn't this also mean that DNA gets progressively longer each time it undergoes replication? Why is this ...
0
votes
1answer
454 views

In the future, it is plausible that we can change the physical appearance of a living animal by editing DNA?

http://www.independent.co.uk/news/science/revealed-scientists-edit-dna-to-correct-adult-genes-and-cure-diseases-9273555.html This article explains that scientists managed to change the DNA of adult ...
11
votes
1answer
2k views

Are all Y-chromosomes the same?

Since the Y-chromosome can only pass from male to male child, it would seem to pass intact. Thus, a boy's Y-chromosomes would, I guess, be the same as his father's. Going backwards, would not all men ...
3
votes
2answers
8k views

What does this equation about DNA replication mean?

Could someone help me understand this equation please? I found it in a paper which said that it was DNA replication, but why? $\ce{dNTP + dNMP_{n} -> dNMP_{n +1} + PPi}$ I found that dNTP means ...
3
votes
1answer
5k views

ATP required for cell processes [closed]

I haven't been able to find anything that tells me how much ATP is needed for DNA replication, transcription, and translation in humans, just papers that mention ATP used in those processes. I need ...
3
votes
1answer
254 views

Specific numbers of nucleotides in Okazaki fragments

Okazaki fragments are formed during replication of the lagging DNA strand. What determines the length of these fragments?
2
votes
2answers
3k 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?...
9
votes
1answer
735 views

When do plasmids replicate relative to its host cell cycle?

For plasmids is so much shorter than their host cell's genome (about 1/1000 in my case), it will take only 1/1000 time for it to replicate. With respect to cell cycle, when will that replication ...
4
votes
1answer
7k 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 replicate the same strand discontinuously and, if so, how/why?
5
votes
1answer
839 views

DNA content doubling in interphase

Why does the DNA content of a cell get doubled in interphase? Why doesn't it become tripled or quadrupled? What's stopping it from doing so?
8
votes
2answers
3k views

How can E. coli proliferate so rapidly?

The E. coli has a genome with approximately 5×106 bp. The main DNA polymerase involved in its chromosome duplication (DNA pol III , the one with highest processivity) can polymerize ~103 nucleotides ...
1
vote
5answers
320 views

Can your immune system's cells destroy you? (Critical thinking and Fictional sense)

In an imaginary sense, If you alone were replicated into 2 so that there should now be 2 of "you" (meaning you both have the same DNA). Then let's say one of you shrunk to the size of a bacteria, and ...
3
votes
2answers
847 views

DNA polymerase I exonuclease activity

Does DNA polymerase I in bacteria use forward or reverse exonuclease activity to remove RNA primers? One of my books says it uses 5' to 3', but another says it uses 3' to 5' exonuclease activity. ...
2
votes
3answers
988 views

How does high-fidelity of DNA replication depend on the formation of hydrogen bonds?

Replication has an error rate of less than 1 in 100 million. DNA polymerase forms H-bond with the H-bond acceptor atoms in the minor groove. <-- enhance fidelity here? Binding of the triphosphate ...
3
votes
1answer
30k views

Does DNA replication in 5' to 3' (leading strand) need RNA primase?

https://www.youtube.com/watch?v=27TxKoFU2Nw In the above video it shows that during DNA replication, the lagging strand require RNA primase to add 3' -OH group for further addition of nucleotides. ...
1
vote
1answer
617 views

Can Mono-Cell or other organism self-replicate?

I have a question regarding how organism replicate them self to create an other organism, We know that in animal reign, we need a male and female that will generate a new being. what I want to know ...
6
votes
1answer
224 views

What regulates the timing of the motion of molecular machines during DNA Replication?

This question is about this video I found on Youtube. I just want to know what is the mechanism which regulates the timing of motion of the parts of these molecular machines. I know that those big ...
3
votes
2answers
810 views

How are DNA segments selected in PCR?

I understand that in PCR we're able to amplify only selected portions of the DNA... however despite reading it from multiple sources, I cannot figure out how this selection actually takes place. I ...