Copying the genome for the purpose of reproduction.

learn more… | top users | synonyms

1
vote
1answer
20 views

In the lysogenic cycle, does the provirus split from the cell's main genetic material for replication?

In a diagram of the lysogenic cycle sent by my instructor in a video, it shows the provirus splitting from the cell's main DNA when the dormancy period ends and the viral DNA is "activated". Is this ...
0
votes
0answers
32 views

Replication of DNA in E. coli: what are DARS and RIDA?

I understand what is DnaA, its role in replication and the fact that it's only active when binding ATP. I don't understand what are DARS and RIDA and how they control the amount of DnaA-ATP:DnaA-ADP
1
vote
1answer
50 views

What is the name of the smallest self-replicating thing?

Some time last year, I found an article on Wikipedia about the smallest something to be able to reproduce. I don't remember exactly what it was, but I am fairly certain that after the initial ...
3
votes
2answers
107 views

Why, specifically, does each generation, on average, improve upon the design of the species rather than degrade it?

In every non-life example I can envision, a copy of a copy is always a degraded or less pure version of the original unless some outside influence acts to correct the copy back toward the ideal ...
2
votes
1answer
275 views

Telomere shortening during replication

It is widely know that each cell cycle during DNA replication some fraction of the telomeres is lost, and this phenomenon is called the end replication problem. Well this is due to the fact that the ...
5
votes
1answer
579 views

Difference in length of Okazaki fragments

The length of Okazaki fragments in the lagging strand is about 100-200 nucleotides in eukaryotes and about 1000-2000 nucleotides in prokaryotes. What (molecular mechanism, enzyme type ) ...
3
votes
1answer
161 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)?
1
vote
1answer
76 views

What is the mechanism of labeling a DNA molecule with deuterated water?

I have seen a paper in which deuterated water was used to follow dividing cells. The assumption was that deuterated water will be incorporated into newly synthesized DNA molecules. Is there any direct ...
1
vote
1answer
93 views

DNA Replication

I just wanted to understand the basic steps behind the replication of the lagging strand of DNA: Have helicase unwind it first DNA Primase lays down RNA primers in fragments, called Okazaki ...
2
votes
1answer
1k views

How does a thymidine block halt DNA synthesis?

The best I've been able to find is that there's a feedback mechanism, but what is this feedback, and how does the mechanism work? If it's just that the concentration of thymidine is too high, why ...
9
votes
2answers
407 views

Which bacteria have the highest mutation rate?

From my reading on M. tuberculosis, I know that this organism has a pretty high mutation rate due to uncorrected sloppy replication, which leads to a high rate of development of spontaneous resistance ...
3
votes
1answer
411 views

What happens when cells in your body run out of telomeres?

In my biology book I read about an experiment where the genes encoding telomerase were 'knocked out', but they could still live a normal life and no adverse effects were noticed until the 6th ...
5
votes
2answers
95 views

Do somatic cells alter their own nucleotide sequence?

I seem to remember reading that embryonic cells will frequently replicate the section of their genome containing rDNA by splicing in duplicate genes. The cells use this to produce ribosomes at a rate ...
9
votes
2answers
152 views

Are there viruses that affect many kinds of cells across species?

I'm not a professional in biology nor a student, but I'm curious about this. To be more specific: why doesn't a plant virus affect animal cells? I suspect that different kinds of cells have different ...
13
votes
3answers
34k views

Why is DNA replication performed in the 5' to 3' direction?

DNA replication goes in the 5' to 3' direction because DNA polymerase acts on the 3'-OH of the existing strand for adding free nucleotides. Is there any biochemical reason why all organisms evolved to ...