Why do eukaryotic telomeres replicate differently?

What is unique about the telomere repeats of eukaryotic chromosomes?

To prevent the loss of genes as chromosome ends wear down, the tips of eukaryotic chromosomes have specialized DNA “caps” called telomeres. Proteins associated with the telomere ends also help protect them and prevent them from triggering DNA repair pathways. …

How do eukaryotic telomeres replicate?

The ends of linear chromosomes, called telomeres, protect genes from getting deleted as cells continue to divide. … Once the lagging strand is elongated by telomerase, DNA polymerase can add the complementary nucleotides to the ends of the chromosomes and the telomeres can finally be replicated.

Why do eukaryotic telomeres get shorter after each round of replication?

At each cell division, the telomeres shorten because of the incomplete replication of the linear DNA molecules by the conventional DNA polymerases. … This is specifically due to the resection and fill-in reaction during the synthesis of the telomere leading-strand [7,8].

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How are telomeres at the ends of eukaryotic chromosomes replicated?

Outline in words and pictures how telomeres at the ends of eukaryotic chromosomes are replicated. Telomeres are replicated by the enzyme telomerase. Telomerase, a ribonucleoprotein, consists of protein and an RNA molecule that is complementary to the 3′ end of the DNA of a eukaryotic chromosome.

How does replication in eukaryotes differ from prokaryotes?

In prokaryotic cells, there is only one point of origin, replication occurs in two opposing directions at the same time, and takes place in the cell cytoplasm. Eukaryotic cells on the other hand, have multiple points of origin, and use unidirectional replication within the nucleus of the cell.

What is the primary reasons s’why eukaryotic chromosomes have telomeres?

Telomeres are the physical ends of eukaryotic chromosomes. They protect chromosome ends from DNA degradation, recombination, and DNA end fusions, and they are important for nuclear architecture. Telomeres provide a mechanism for their replication by semiconservative DNA replication and length maintenance by telomerase.

Why do eukaryotic cells have multiple origins of replication?

Because eukaryotic chromosomes are linear and much larger than prokaryotic ones, there are multiple origins of replication in the eukaryotic genome during replication. This means that replication can occur simultaneously in hundreds to thousands of locations along each chromosome.

How do eukaryotes solve 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.

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Why can’t the ends of chromosomes be replicated?

The end-replication problem states that small stretches of DNA at the 3′ ends of chromosomes cannot be copied because these stretches are not covered by Okazaki fragments. Because of the end-replication problem, chromosome ends are slowly shortened over time.

Why do telomeres shorten with each cell division?

The telomere acts as a buffer to ensure the important genetic information coded for on the chromosome is completely copied for each new cell and protected from damage. Over time, this results in fewer and fewer DNA repeats making up the telomeres after each cell division i.e. gradually the telomeres shorten.

Why does telomere shortening occur?

Why do telomeres get shorter? Your DNA strands become slightly shorter each time a chromosome replicates itself. Telomeres help prevent genes from being lost in this process. But this means that as your chromosomes replicate, your telomeres shorten.

Which would you expect of a eukaryote lacking telomerase?

A eukaryotic cell lacking telomerase would shorten the ends of its chromosomes with every replication.

How do the linear chromosomes in eukaryotes ensure that its ends are replicated completely?

How do the linear chromosomes in eukaryotes ensure that its ends are replicated completely? Telomerase has an inbuilt RNA template that extends the 3′ end, so primer is synthesized and extended. Thus, the ends are protected.

How does telomerase prevent linear chromosomes from shortening during replication quizlet?

Explain how telomerase prevents linear chromosomes from shortening during replication. Telomerase binds to the overhang at the end of a chromosome. Once bound, it begins catalyzing the addition of deoxyribonucleotides to the overhang in the 5′ -> 3′ direction, lengthening the overhang.

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In what ways is eukaryotic replication similar to bacterial replication and in what ways is it different quizlet?

Eukaryotic DNA replication differs from bacterial replication in that: (1) It has multiple origins of replications per chromosome. (2) It has several different DNA polymerases with different functions. (3) Immediately following DNA replication, assembly of nucleosomes takes place.