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1answer
38 views

How does DNA Polymerase make errors? [on hold]

DNA Polymerase inserts the wrong nucleic acid base into DNA at a rate estimated to be between 1 in 107 and 1 in 108. How does it determine which base to match to the template strand, and how does it ...
10
votes
1answer
225 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 ...
0
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2answers
44 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
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1answer
18 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.
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0answers
32 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 ...
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0answers
16 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 ...
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0answers
79 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
55 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
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1answer
57 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 ...
0
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0answers
21 views

Separate replication origin and terminus vs making them one and the same

The classical picture of bacterial reproduction has a replication origin on one side of the circular chromosome and a replication termination area on the opposite end. This essentially creates two ...
3
votes
1answer
54 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
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2answers
48 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
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1answer
114 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 ...
3
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0answers
20 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 ...
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2answers
207 views

What errors can occur during DNA replication?

When there is an error in copying DNA (a mutation), what exactly goes wrong? If G goes with C and A goes with T, I don't see how that part can mess up. Is the idea that when the double helix is ...
5
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1answer
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 ...
0
votes
1answer
66 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?
1
vote
1answer
39 views

Why isn't the RNA 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,...
2
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1answer
1k 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 ...
0
votes
1answer
107 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....
0
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1answer
94 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 so ...
3
votes
1answer
61 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 , ...
-6
votes
1answer
90 views

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

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
6
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1answer
89 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
83 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 ...
9
votes
1answer
1k 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 ...
2
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1answer
109 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?
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
votes
1answer
99 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?
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5answers
122 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
403 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 ...
0
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2answers
295 views

DNA sequence from the middle of a gene

Someone gives you a short DNA sequence that comes from the middle of a gene. 5'- TCTAACTGATTAGC -3' 3'- AGATTGACTAATCG -5' From this sequence, determine the ...