Package 18

Which enzyme catalyzes the formation of covalent bonds between adjacent Okazaki fragments to complete the replication process?

Ligase

During DNA replication, the lagging strand is synthesized as a series of small fragments called----fragments

Okazaki

conservative mechanism

One new double-stranded DNA molecule contains two parental strands while the other molecule contains two daughter strands

Telomerase is made up of which of the following? Select all that apply.

Protein RNA

The Meselson and Stahl experiments supported this method of replication.

Semiconservative

There are relatively few errors during DNA replication due to the proofreading mechanisms by

DNA polymerase

In the late 1950s, three different models were proposed for the process of DNA replication. These were the --- mechanism, --- mechanism, and ---mechanism.

semiconservative, conservative, dispersive

leading strand

synthesized continuously

lagging strand

synthesized in small fragments that are later connected

The enzyme ---attaches DNA sequences at the ends of eukaryotic chromosomes.

telomerase

This enzyme prevents chromosomal shortening by attaching a repeat sequence to the ends of chromosome

telomerase

This is a region at the ends of eukaryotic chromosomes.

telomere

The RNA portion of telomerase is ---to the DNA repeat sequence.

complementary

All models of DNA replication include

daughter strands. parental strands.

Free nucleotides with three phosphate groups are called

deoxynucleoside triphosphate

The term high --- refers to a process that occurs with relatively few mistakes.

fidelity

Energy is generated to covalently connect adjacent molecules by breaking the bond between the---

first and second phosphates in the dNTP

A telomere

has a 3' overhang

In human cancer cells, telomerase is present in what level as compared to normal cell?

higher

In DNA replication, the ______ strand is made discontinuously in the direction opposite to the movement of the replication fork.

lagging

During DNA replication, the ---- strand is synthesized continuously while the ---- strand is synthesized as small fragments that are connected to each other to form a continuous strand.

leading lagging

The --- of replication is a site within a chromosome where DNA replication begins.

origin

During DNA replication, new strands are synthesized from --- strands on the original molecule.

parental

DNA template strands are referred to as ______ strands, while the newly synthesized strands are referred to as ______ strands.

parental; daughter

The enzyme ---- DNA covalently links nucleotides to synthesize new DNA strands together during DNA replication.

polymerase

What DNA enzyme covalently links nucleotides together?

polymerase

In order to start DNA synthesis on a bare template, this enzyme is needed

primase

Place the steps of semiconservative DNA replication in proper order. Start with the first step on top.

1. The Double helix separates 2. Nucleotides hydrogen bond to the template strand 3. covalent bonds form between sugars and phosphate 4. daughter strands are produced for each template strand.

The following represent steps in the process of DNA replication by telomerase. Arrange them in the right order, with the first step on top. Position 1 of 5 Telomerase binds to a DNA repeat sequence correct toggle button unavailable

1. telomerase bind to DNA repeat sequence 2. telomerase synthesis a 6-nucleotide repeat sequence 3.Telomerase moves six nucleotide to the night and begins to make a mother repeat 4. Primase make an RND... 5.DNA polymerase ...

In order to complete synthesis of the Okazaki fragments on the lagging strand, the following must occur. Place these items in the correct order. Start with the earliest on top.

1. the removal of RNA primers 2. The synthesis of DNA in the area where the primers have been removed 3. the covalent joining of adjacent fragment of DNA

During DNA replication, how many strands of DNA are used as templates to synthesize new strands?

2

The enzyme DNA polymerase attaches a nucleotide to the ______ end of a growing strand via a ______ bond.

3' ; phosphoester

Once synthesis has begun, DNA can only be synthesized in this direction

5' to 3'

The sequence repeated in human telomeres is

5'-GGGTTA-3'

Once replication has begun, new ---- can only be synthesized in a 5' to 3' direction.

DNA

This process occurs near the opening of replication forks

DNA replication

An origin of replication is a site within a chromosome where

DNA replication begins

The DNA polymerase that removes RNA primers and fills in the regions between fragments is

I

Semiconservative mechanism

The two new double-stranded DNA molecules each contains one parental strand and one daughter strand

Dispersive mechanism

The two new double-stranded DNA molecules each contains segments of parental and daughter DNA interspersed in both strands

During DNA replication, the lagging strand of DNA is synthesized in a 5' to 3' direction as DNA polymerase moves ______ the replication fork.

away from

DNA replication is described as ______ because DNA replication proceeds outward from two replication forks.

bidirectional

Telomerase function is associated with

cancer

An RNA --- is required to produce each Okazaki fragment in Escherichia coli.

primer

DNA polymerase can detect a mismatched nucleotide and remove it from the daughter strand. It does so by digesting the linkages in the 3' to 5' direction to remove the incorrect base and then changing direction to synthesize again in the 5' to 3' direction. This process is called

proofreading

DNA replication occurs near the opening that forms each

replication fork