Mastering Bio Ch 16

E

After DNA replication is completed, _____. A. one DNA double helix consists of two old strands and one DNA double helix consists of two new strands B. each new DNA double helix consists of two new strands C. each of the four DNA strands consists of some old strand parts and some new strand parts D. there are four double helices E. each new DNA double helix consists of one old DNA strand and one new DNA strand

C

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. A. labeled protein ... DNA B. labeled protein .... protein C. labeled DNA ... DNA D. labeled DNA .... protein E. labeled DNA ... labeled protein

C

An old DNA strand is used as a _____ for the assembly of a new DNA strand. A. complement B. primer C. template D. source of nucleotides E. model

A

DNA replication is said to be semiconservative. What does this mean? A. Each new double helix consists of one old and one new strand. B. One of the two resulting double helices is made of two old strands, and the other is made of two new strands. C. The old double helix is degraded and half of its nucleotides are used in the construction of two new double helices. D. Half of the old strand is degraded and half is used as a template for the replication of a new strand. E. One strand of the new double helix is made of DNA and the other strand is made of RNA.

B

Daughter strand elongates away from replication fork A. Leading strand B. Lagging strand C. Both strands

A

Daughter strand elongates toward replication fork A. Leading strand B. Lagging strand C. Both strands

B

During DNA replication, the leading strand is synthesized continuously, whereas the lagging strand is synthesized as Okazaki fragments. Why is this so? A. DNA polymerases can bind to only one strand at a time. B. DNA synthesis can take place only in the 5' to 3' direction. C. There are thousands of origins of replication on the lagging strand but only one on the leading strand.

C

Early, flawed DNA models proposed by Watson and Crick and by Linus Pauling correctly described which property of DNA? A. DNA is a double helix. B. Bases pair with complementary bases. C. DNA is composed of sugars, phosphates, and bases. D. Bases face the center of the molecule, with a phosphate backbone on the outside.

c

Erwin Chargaff observed that the proportions of adenine (A) and thymine (T) bases were always equal, as were the proportion of guanine (G) and cytosine (C). Chargaff's observation suggests which of the following statements? A. Chargaff's observation suggests a mechanism by which DNA can replicate itself. B. Chargaff's observation suggests that all animals have the same amount of A, T, C, and G in their cells. C. The data suggest that A would always pair with T and G would always pair with C in a DNA molecule. D. Chargaff's observation suggests that identical bases on the two DNA strands would pair with each other--for example, A would pair with A.

A

Hershey and Chase used _____ to radioactively label the T2 phage's proteins. A. 35S B. 32P C. 14C D. 92U E. 222Ra

B

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. A. guanine ... adenine B. thymine ... cytosine C. cytosine ... uracil D. uracil ... cytosine E. cytosine ... thymine

B

In a nucleotide, the nitrogenous base is attached to the sugar's _____ carbon and the phosphate group is attached to the sugar's _____ carbon. A. 1' ... 3' B. 1' ... 5' C. 1' ... 2' D. 2' ... 3' E. 2' ... 1

A

In his work with pneumonia-causing bacteria and mice, Griffith found that A. some substance from pathogenic cells was transferred to nonpathogenic cells, making them pathogenic. B. the protein coat from pathogenic cells was able to transform nonpathogenic cells. C. bacteriophages injected DNA into bacteria. the polysaccharide coat of bacteria caused pneumonia. D. heat-killed pathogenic cells caused pneumonia.

A, B, C

In the 1950s, when Watson and Crick were working on their model of DNA, which concepts were well accepted by the scientific community? Select all that apply. A. Genes are located on chromosomes. B. Chromosomes are made up of protein and nucleic acid. C. Chromosomes are found in the nucleus. D. Genes are made of DNA.

D

In the Hershey and Chase experiment that helped confirm that DNA, not protein, was the hereditary material, what was the key finding? A. Radioactively labeled phosphorus was found outside of the infected bacteria. B. Radioactively labeled carbon was present inside the infected bacteria. C. Radioactively labeled sulfur was found outside of the infected bacteria. D. Radioactively labeled phosphorus was present inside the infected bacteria. E. Radioactively labeled sulfur was present inside the infected bacteria.

D

In the early 1950s, many researchers were racing to describe the structure of DNA using different approaches. Which of the following statements is true? A. Jim Watson and Francis Crick used X-ray diffraction to understand the structure of DNA. B. Rosalind Franklin and Maurice Wilkins conducted genetic experiments to explore DNA's role in inheritance. C. Rosalind Franklin and Maurice Wilkins built theoretical models, incorporating current knowledge about chemical bonding and X-ray data. D. Jim Watson and Francis Crick built theoretical models, incorporating current knowledge about chemical bonding and X-ray data.

A

Made continuously A. Leading strand B. Lagging strand C. Both strands

B

Made in segments A. Leading strand B. Lagging strand C. Both strands

B

Multiple primers needed A. Leading strand B. Lagging strand C. Both strands

C

Nucleic acids are assembled in the _____ direction. A. 5' to 1' B. 4' to 5' C. 5' to 3' D. 1' to 5' E. 2' to 3

A

Only 1 primer needed A. Leading strand B. Lagging strand C. Both strands

C

Synthesized 5' to 3' A. Leading strand B. Lagging strand C. Both strands

E

The action of helicase creates _____. A. primers and replication bubbles B. DNA fragments and replication bubbles C. DNA fragments and replication forks D. primers and DNA fragments E. replication forks and replication bubbles

C

The first step in the replication of DNA is catalyzed by _____. A. ligase B. single-strand binding protein C. helicase D. DNA polymerase E. primase

leading strand

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

E

The radioactive isotope 32P labels the T2 phage's _____. A. head B. tail C. protein coat D. base plate E. DNA

A

The synthesis of a new strand begins with the synthesis of a(n) _____. A. RNA primer complementary to a preexisting DNA strand B. Okazaki fragment C. poly(A) tail D. single-strand binding protein E. short pieces of DNA

C

This is an image of a(n)... A. amino acid B. nucleic acid C. nucleotide D. none of the above

E

This is an image of a... A. moneran B. protist C. red blood cell D. bacterium E. phage

True

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.

C

What are chromosomes made of? A. DNA, RNA, and proteins B. DNA, heterochromatin, and histone proteins C. DNA and proteins D. DNA and euchromatin E. DNA

B, C, D

What are the chemical components of a DNA molecule? Select all that apply. A. proteins B. nitrogenous bases C. phosphate groups D. sugars E. amino acids

B

What are the repetitive DNA sequences present at the ends of eukaryotic chromosomes called? A. polypeptides B. telomeres C. centromeres D. sarcomeres E. chromomeres

D

What catalyzes DNA synthesis? A. Replication fork B. dNTPs C. Primer D. DNA polymerase

B

What did Rosalind Franklin's famous photo 51 show? A. DNA is replicated by making identical copies of each strand. B. DNA is a helix. C. Complementary DNA bases pair with one another (A with T and G with C). D. Chromosomes are made of DNA and proteins.

A, B, D

What did the structure of DNA's double helix suggest about DNA's properties? Select all that apply. A. DNA can be replicated by making complementary copies of each strand. B. DNA stores genetic information in the sequence of its bases. C. DNA is found in the nucleus. D. DNA can change. Errors in copying can result in changes in the DNA sequence that could be inherited by future generations.

B

Which of the following enzymes creates a primer for DNA polymerase? A. Helicase B. Primase C. Topoisomerase D. Ligase

B

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

E

Which of the following is true of DNA during interphase? A. It exists as chromatin and is unavailable for gene expression. B. It exists as chromatin; it is completely uncoiled and loose. C. It is in the form of highly condensed chromosomes and is unavailable for gene expression. D. It is in the form of highly condensed chromosomes; it is called heterochromatin. E. It exists as chromatin and is less condensed than mitotic chromosomes.

A

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

A

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

E

Which of these is a difference between a DNA and an RNA molecule? A. DNA contains nitrogenous bases, whereas RNA contains phosphate groups. B. DNA contains five-carbon sugars, whereas RNA contains six-carbon sugars. C. DNA contains uracil, whereas RNA contains thymine. D. DNA is a polymer composed of nucleotides, whereas RNA is a polymer composed of nucleic acids. E. DNA is usually double-stranded, whereas RNA is usually single-stranded.

D

Which of these nitrogenous bases is found in DNA but not in RNA? A. adenine B. cytosine C. guanine D. thymine E. uracil

C

Which part of a deoxynucleoside triphosphate (dNTP) molecule provides the energy for DNA synthesis? A. Base B. Free 3' hydroxyl (-OH) group C. Phosphate groups D. Sugar

D

Who conducted the X-ray diffraction studies that were key to the discovery of the structure of DNA? A. Meselson and Stahl B. McClintock C. Griffith D. Franklin E. Chargaff

D

Who demonstrated that DNA is the genetic material of the T2 phage? A. Meselson and Stahl B.Franklin C. Watson and Crick D. Hershey and Chase E. Darwin and Wallace

E

Why is the new DNA strand complementary to the 3' to 5' strands assembled in short segments? A. only short DNA sequences can extend off the RNA primers B. the replication forks block the formation of longer strands C. DNA polymerase can assemble DNA only in the 3' to 5' direction D. it is more efficient than assembling complete new strands E. DNA polymerase can assemble DNA only in the 5' to 3' direction

Okazaki fragments

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