What happens when DNA replication reaches the end of a linear chromosome?

When the replication fork reaches the end of the linear chromosome, there is no way to replace the primer on the 5′ end of the lagging strand. The DNA at the ends of the chromosome thus remains unpaired, and over time these ends, called telomeres, may get progressively shorter as cells continue to divide.

What happens to the ends of linear chromosomes in DNA 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.

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What is the end result of DNA replication?

The result of DNA replication is two DNA molecules consisting of one new and one old chain of nucleotides. This is why DNA replication is described as semi-conservative, half of the chain is part of the original DNA molecule, half is brand new.

What is the end of chromosome problem for linear replication quizlet?

with a linear chromosome, on the lagging strand (template 5′->3′) of DNA replication, when the last piece of RNA primer at the 3′ end is removed, the DNA cannot be extended and this creates the end replication problem.

What is the problem that occurs at the ends of the eukaryotic chromosome during replication?

what is the problem that occurs at the ends of the eukaryotic 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.

What happens to the ends of linear chromosomes during each round of replication and how do cells address this problem?

The ends of the chromosomes pose a problem during DNA replication as polymerase is unable to extend them without a primer. Telomerase, an enzyme with a built-in RNA template, extends the ends by copying the RNA template and extending one end of the chromosome. DNA polymerase can then extend the DNA using the primer.

Why is one end of a DNA strand called the 5 end?

One end is referred to as 5′ (five prime) and the other end is referred to as 3′ (three prime). The 5′ and 3′ designations refer to the number of carbon atom in a deoxyribose sugar molecule to which a phosphate group bonds.

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What is the end result of DNA replication quizlet?

The outcome of DNA replication is two DNA nearly identical DNA double helix molecules. Each DNA is made up of one DNA strand from the original DNA and a newly created strand.

In what phase does DNA replication occur?

In the eukaryotic cell cycle, chromosome duplication occurs during “S phase” (the phase of DNA synthesis) and chromosome segregation occurs during “M phase” (the mitosis phase).

What is the end result of translation?

When the ribosome reaches a stop codon, it releases the mRNA strand and amino acid sequence. The amino acid sequence is the final result of translation, and is known as a polypeptide. Polypeptides can then undergo folding to become functional proteins.

How is the end replication problem solved?

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.

Where does the end replication issue happen?

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 cause of the end replication problem quizlet?

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!

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What is end replication problem?

Abstract. 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.

How do eukaryotes replicate DNA?

In eukaryotes, the vast majority of DNA synthesis occurs during S phase of the cell cycle, and the entire genome must be unwound and duplicated to form two daughter copies. … This mechanism is conserved from prokaryotes to eukaryotes and is known as semiconservative DNA replication.

What happens during initiation of DNA replication?

During initiation, proteins bind to the origin of replication while helicase unwinds the DNA helix and two replication forks are formed at the origin of replication. During elongation, a primer sequence is added with complementary RNA nucleotides, which are then replaced by DNA nucleotides.