What is the problem that occurs at the ends of the chromosome during replication?
the 5′ end of DNA strands have no way to be completed
, and as a result of repeated rounds of replication, the DNA will become shorter and shorter. DNA sequence that does not code for genes.
What is the problem that occurs at the ends of the eukaryotic chromosome during replication?
Unlike bacterial chromosomes, the chromosomes of eukaryotes are linear (rod-shaped), meaning that they have ends. These ends pose a problem for DNA replication. The DNA at the
very end of the chromosome cannot be fully copied in each round of replication
, resulting in a slow, gradual shortening of the chromosome.
What is the end replication problem in DNA replication?
The end replication problem hypothesis
proposes that the ends of linear DNA cannot be replicated completely during lagging strand DNA synthesis
. Although the idea has been widely accepted for explaining telomere attrition during cell proliferation, it has never been directly demonstrated.
What causes end replication problem?
At each cell division, the telomeres shorten because of the incomplete replication of the linear DNA molecules by the conventional DNA polymerases. This is called the end replication problem [6]. This is specifically due to
the resection and fill-in reaction during the synthesis of the telomere leading-strand
[7,8].
What is the end replication problem quizlet?
1)What is the end replication problem ? … 1)
When replication gets to the end of the amplicon, the primer doesn’t have a place to lay it`s primers so there`s no where DNA polymerase can synthesize a new strand
. 2) This only happens in the lagging strand. You just studied 21 terms!
Why does the presence of telomeres protect the ends of linear chromosomes group of answer choices?
Why does the presence of telomeres protect the genetic information of linear chromosomes from loss? The
telomeres represent large buffer zones of DNA sequence that
do not code for biomolecules. … Telomerase in incapable of elongating DNA in the 3′ to 5′ direction to solve “end replication problem”.
Why can nucleotides only be added to the 3 end?
DNA polymerase will add the free DNA nucleotides using complementary base pairing
(A-T and C-G)
to the 3′ end of the primer this will allow the new DNA strand to form. … Nucleotides cannot be added to the phosphate (5′) end because DNA polymerase can only add DNA nucleotides in a 5′ to 3′ direction.
What solves the end replication problem?
Eukaryotes have solved the end-replication problem by
locating highly repeated DNA sequence at the end, or telomeres, of each linear chromosome
. … In prokaryotes, the end-replication problem is solved by having circular DNA molecules as chromosomes. Another cause of telomere shortening is oxidative stress.
Is DNA lost during replication?
After sufficient rounds of replication,
all the telomeric repeats are lost
, and the DNA risks losing coding sequences with subsequent rounds. The discovery of the enzyme telomerase helped in the understanding of how chromosome ends are maintained.
Why do bacteria not need telomerase?
Bacteria don’t need telomerase
because their chromosomes don’t have telomeres
. Most bacterial chromosomes are circular, meaning they have no end.
What is the result of DNA ligase’s action?
What is the result of DNA ligase’s action?
DNA is broken up at specific sites
. DNA translation occurs. … A daughter strand of DNA produced during chromosome replication can be composed of leading and lagging strands from different replication bubbles.
What supplements lengthen telomeres?
Candidates include
vitamin D, omega-3 fatty acids
, and TA-65, a product that purportedly contains extracts of astragalus membranaceus, a plant-based compound that demonstrates immunomodulatory, anti-oxidative stress, and anti-aging effects, the latter of which are associated with longer telomeres.
What is telomere replication?
The ends of the linear chromosomes are known as telomeres:
repetitive sequences that code for no particular gene
. … Once the 3′ end of the lagging strand template is sufficiently elongated, DNA polymerase adds the complementary nucleotides to the ends of the chromosomes; thus, the ends of the chromosomes are replicated.
Which enzyme removes RNA primers and replaces them with DNA?
Because of its 5′ to 3′ exonuclease activity,
DNA polymerase I
removes RNA primers and fills the gaps between Okazaki fragments with DNA.
What is the function of a telomere?
Their job is
to stop the ends of chromosomes from fraying or sticking to each other
, much like the plastic tips on the ends of shoelaces. Telomeres also play an important role in making sure our DNA gets copied properly when cells divide.
Which process ensures the high accuracy of replication?
The cell has multiple mechanisms to ensure the accuracy of DNA replication. The first mechanism is the use of a faithful
polymerase enzyme
that can accurately copy long stretches of DNA. The second mechanism would be for the polymerase to catch its own mistakes and correct them.
