Chapter 13 REVIEW

The sticky end of the DNA restriction fragment shown here will pair with a DNA restriction fragment with the sticky end _____.

-ACGT

Hershey and Chase used _____ to radioactively label the T2 phage's proteins.

35S

Nucleic acids are assembled in the _____ direction.

5' to 3'

Where would RNA polymerase attach?

A RNA polymerase attaches to DNA

In the accompanying image, a nucleotide is indicated by the letter _____.

B

A nitrogenous base is indicated by the letter _____.

C

Which of these is(are) pyrimidines?

C, D, and E *Pyrimidines are single-ring structures

Which of these is responsible for catalyzing the formation of an RNA primer?

D Primase catalyzes the formation of an RNA primer.

The radioactive isotope 32P labels the T2 phage's _____.

DNA

What are chromosomes made of?

DNA and proteins

Which of these is a difference between a DNA and an RNA molecule?

DNA is usually double-stranded, whereas RNA is usually single-stranded.

The enzyme that can replicate DNA is called

DNA polymerase

What catalyzes DNA synthesis?

DNA polymerase

Why is the new DNA strand complementary to the 3' to 5' strands assembled in short segments?

DNA polymerase can assemble DNA only in the 5' to 3' direction

Which of these DNA molecules is the shortest?

E The shorter the DNA molecule, the farther it moves.

Who conducted the X-ray diffraction studies that were key to the discovery of the structure of DNA?

Franklin

Who demonstrated that DNA is the genetic material of the T2 phage?

Hershey and Chase

The letter C indicates _____.

Histones

Nucleotides are added to a growing DNA strand as nucleoside triphosphates. What is the significance of this fact?

Hydrolysis of the two phosphate groups (P-Pi) and DNA polymerization are a coupled exergonic reaction. Submit

Which of the following is true of DNA during interphase?

It exists as chromatin and is less condensed than mitotic chromosomes.

The new DNA strand that grows continuously in the 5' to 3' direction is called the

Leading strand

Short segments of newly synthesized DNA are joined into a continuous strand by _____.

Ligase

are the short sections of DNA that are synthesized on the lagging strand of the replicating DNA

Okazaki fragments

Which part of a deoxynucleoside triphosphate (dNTP) molecule provides the energy for DNA synthesis?

Phosphate groups The potential energy stored in the bonds of the phosphates provides the energy for DNA synthesis.

Which of the following enzymes creates a primer for DNA polymerase?

Primase This RNA polymerase synthesizes an RNA primer antiparallel to the template DNA strand.

Which of the following statements about DNA synthesis is true? As DNA polymerase moves along the template strand, each new nucleotide provides a 5' hydroxyl group for the next reaction to occur. DNA polymerase adds dNTP monomers in the 3' to 5' direction. Nucleotides are added in a random fashion to single-stranded DNA. Primers are short sequences that allow the initiation of DNA synthesis.

Primers are short sequences that allow the initiation of DNA synthesis.

The synthesis of a new strand begins with the synthesis of a(n) _____.

RNA primer complementary to a preexisting DNA strand Submit

During DNA replication, an open section of DNA, in which a DNA polymerase can replicate DNA, is called a

Replication fork

DNA is a self-replicating molecule. What accounts for this important property of DNA?

The nitrogenous bases of the double helix are paired in specific combinations: A with T and G with C.

Griffith's experiments with S. pneumoniae were significant because they showed that traits could be transferred from one organism to another. What else did he find that was significant?

The transferred traits were heritable.

Which of the following statements about Okazaki fragments in E. coli is true? They are sealed together by the action of helicase. They are usually 50 to 500 bases long. They are synthesized in the 3' to 5' direction. They are formed on the lagging strand of DNA.

They are formed on the lagging strand of DNA.

Which of these nitrogenous bases is found in DNA but not in RNA?

Thymine

Which of the following enzymes is important for relieving the tension in a helix as it unwinds during DNA synthesis? Helicase Single-strand binding proteins Ligase Topoisomerase

Topoisomerase

True or false? Single-stranded DNA molecules are said to be antiparallel when they are lined up next to each other but oriented in opposite directions.

True **When the 3' end of one DNA strand points in the same direction as the 5' end of the other DNA strand, the strands are said to be antiparallel.

The letter A indicates _____.

a DNA double helix

In recombinant DNA experiments, what is used to cut pieces of DNA and what joins the resulting fragments to form recombinant DNA?

a restriction enzyme ... DNA ligase Restriction enzymes cut DNA molecules at specific points; in most cases, the restriction fragments have sticky ends that can base-pair with complementary sticky ends. The joined segments are then covalently fused by DNA ligase.

In a nucleotide, the nitrogenous base is attached to the sugar's _____ carbon and the phosphate group is attached to the sugar's _____ carbon.

c) 1' ... 5'

After replication is complete, the new DNAs, called ________, are identical to each other

daughter DNA

After DNA replication is completed, _____.

each new DNA double helix consists of one old DNA strand and one new DNA strand

The first step in the replication of DNA is catalyzed by _____.

helicase

Which of the following is an example of "recombinant DNA technology"?

introducing a human gene into a bacterial plasmid

After allowing phages grown with bacteria in a medium that contained 32P and 35S, Hershey and Chase used a centrifuge to separate the phage ghosts from the infected cell. They then examined the infected cells and found that they contained _____, which demonstrated that _____ is the phage's genetic material.

labeled DNA ... DNA

What is this an image of?

loops

In gel electrophoresis DNA molecules migrate from _____ to _____ ends of the gel.

negative ... positive (An electrical current is generated across the gel, and DNA molecules migrate from the negative end toward the positive end.)

In nucleotide excision repair, damaged DNA is excised by what enzyme(s)?

nuclease

This is an image of a(n) _____.

nucleotide

What process repairs damage to a preexisting double helix?

nucleotide excision repair

This is an image of a _____.

phage This is a T2 phage, a type of phage that infects E. coli.

The letter A indicates ______.

phosphate group

Which of the following enzymes synthesizes short segments of RNA?

primase

The action of helicase creates _____.

replication forks and replication bubbles

The unpaired nucleotides produced by the action of restriction enzymes are referred to as _____.

sticky ends

You can tell that this is an image of a DNA nucleotide and not an RNA nucleotide because you see a _____.

sugar with two, and not three, oxygen atoms

What is this an image of?

supercoils

What are the repetitive DNA sequences present at the ends of eukaryotic chromosomes called?

telomeres

An old DNA strand is used as a _____ for the assembly of a new DNA strand.

template **An old DNA strand is used as a template for the synthesis of a complementary new strand.

In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the complementary strand, and a guanine of one strand always pairs with a(n) _____ of the complementary strand.

thymine....cytosine

Archaeologists unearthed a human skull with a small dried fragment of the scalp still attached. They extracted a tiny amount of DNA from the scalp tissue. How could they obtain sufficient DNA for an analysis of the ancient human's genes?

use the polymerase chain reaction