Deck 6: DNA: The Thread of Life

Question 1

Hershey and Chase performed an experiment in which they used radioactive isotopes of phosphorus and sulfur to label different components of bacterial viruses. Their results clearly showed that

A)DNA was entering into the infected bacteria.
B)the viruses did not contain protein.
C)the viruses did not contain DNA.
D)protein was entering into the infected bacteria.
E)genetic material normally contains radioactive isotopes.

Answer 1

A

Question 2

DNA replication occurs

A)during cell division.
B)continuously.
C)before cell division.
D)only once in the life of the organism.
E)only in gametes.

Answer 2

C

Question 3

If DNA is likened to a ladder, what are the compounds that make up the sides of the ladder?

A)phosphates and bases
B)phosphates and sugars
C)bases only
D)phosphates only
E)bases and sugars

Answer 3

B

Question 4

DNA replication involves all of the following steps except

A)separation.
B)joining.
C)production of single-stranded DNA molecules.
D)complementary base pairing.
E)polymerization.

Question 5

What step in DNA replication precedes the pairing of complementary bases?

A)polymerization of DNA
B)separation of the two strands
C)joining of the two strands
D)mitotic division
E)formation of the histone core

Question 6

What is the sugar molecule found in DNA?

A)ribose
B)phosphatase
C)deoxyribose
D)oxyribose
E)polymerase

Question 7

A package of histones with DNA wrapped around them forms spherical structures called

A)nucleoli.
B)chromatin.
C)nucleosomes.
D)ribosomes.
E)lysosomes.

Question 8

In a DNA double helix, each loop of the helix

A)is wound around histone proteins.
B)consists of 10 nucleotides.
C)always contains equal amounts of G and T.
D)contains the sugar-phosphate backbones in the interior of the helix.
E)represents one nucleotide.

Question 9

The structure of DNA was determined primarily by

A)Mendel.
B)Watson and Crick.
C)Pauling.
D)Hershey and Chase.
E)Griffith.

Question 10

DNA replication of a single DNA molecule is referred to as semiconservative because

A)it results in two nonidentical DNA molecules.
B)one DNA strand is replicated continuously, while the other must be replicated discontinuously.
C)of the two DNA molecules, one is made up totally of parental DNA, while the other is entirely newly synthesized DNA.
D)all the DNA strands in the two DNA molecules will have both parental and newly synthesized DNA.
E)each of the two DNA molecules will consist of one parental strand and one newly synthesized strand.

Question 11

Genes are composed of

A)DNA.
B)proteins.
C)chromosomes.
D)carbohydrates.
E)lipids.

Question 12

The fact that the two strands composing a DNA molecule are called antiparallel has to do with the orientation of the

A)sugar molecules.
B)bases.
C)phosphate molecules.
D)hydrogen bonds.
E)sulfide bonds.

Question 13

Which is not true of DNA replication?

A)It occurs in the S phase of the cell cycle.
B)It functions similarly for all organisms.
C)It is semiconservative.
D)Both strands are synthesized in one direction only.
E)Both strands are synthesized continuously.

Question 14

Base pairing

A)occurs between identical bases.
B)requires hydrogen bonds.
C)takes place between sugars and phosphates on the two strands in a helix.
D)explains the X-ray results from Rosalind Franklin.
E)occurs between A and C.

Question 15

DNA replication

A)occurs in the cytoplasm of the cell.
B)does not require proteins.
C)occurs in G₁ of interphase.
D)takes place in the nucleus of the cell.
E)is constantly happening in a cell.

Question 16

Which of the researchers that elucidated the structure of DNA did not receive a Nobel Prize?

A)Wilkins
B)Franklin
C)Crick
D)Watson
E)All 4 received the Nobel.

Question 17

Frederick Griffith conducted experiments where nonlethal bacteria acquired the ability to cause lethal pneumonia due to the presence of an unknown chemical. This chemical was later found to be

A)RNA.
B)a protein.
C)DNA.
D)nonhereditary material.
E)phosphorus.

Question 18

The two strands of DNA in a DNA double helix

A)are identical to each other.
B)are connected to each other by covalent chemical bonds.
C)both contain nucleotides, but the order of the nucleotides on the two strands is not related.
D)are oriented in the same direction.
E)are antiparallel to each other.

Question 19

Packaged DNA is referred to as

A)chromosomes.
B)histones.
C)chromatin.
D)protein.
E)nucleosomes.

Question 20

The most important experimental result that suggested to Watson and Crick that DNA was in the form of a helix was

A)the finding of Chargaff that DNA always had equal amounts of A and T and equal amounts of G and C.
B)Griffith's results with transformation.
C)the discovery that DNA is wound around histone proteins.
D)X-ray data from Rosalind Franklin .
E)understanding DNA replication.

Question 21

Bacteriophages were used by Hershey and Chase to further elucidate our understanding of heredity. Why were bacteriophages used?

Question 22

Normal human body cells contain how many chromosomes?

A)22
B)23
C)46
D)44
E)42

Question 23

The structure of DNA is often described as a twisted ladder. The rungs of the ladder represent the sugar phosphate chains. Is this an accurate description? Why or why not?

Question 24

Match the following steps in DNA replication with the correct descriptive term that either describes
the step or describes why the step is necessary.
1. joining ____
2. separation ___
3. complementary base pairing ___
A, Replication cannon occur if DNA is present as a helix.
B. Free nucleotides will form hydrogen bonds with unpaired bases.
C. The new strand is formed from the newly paired bases.

Question 25

Match the following terms with their characteristics.
4. ____ DNA polymerase
5. ____ nucleotide
6. ____ histone
7. ____ bases of DNA
A. building block of DNA
B. joins nucleotides during DNA replication
C. cytosine, guanine, adenine, and thymine
D. spool of protein associated with DNA

Question 26

DNA evidence is sometimes used to address what legal issues? How reliable is DNA evidence in a court of law?

Question 27

Describe how the discovery of the structure of DNA is an example of the fact that science is a process that always builds on previous work.

Question 29

What was the significance of Griffith's and Avery's "transformed" cells?

Question 30

Why do geneticists refer to the two sugar phosphate strands of DNA as "antiparallel"?

Question 32

It is discovered that a chromosome from the cells of a particular organism is made up of a strand of DNA that is 500 base pairs long. If 30% of the DNA molecule is determined to be made up of adenine, how many of the bases would you expect to be guanine?

Question 33

The bases are bonded to what part of the backbone of the DNA molecule?

A)the 1' carbon atom of the sugar molecule
B)the 2' carbon atom of the sugar molecule
C)the 3' carbon atom of the sugar molecule
D)the 4' carbon atom of the sugar molecule
E)the 5' carbon atom of the sugar molecule

Question 34

Why is it important that DNA replication be so accurate but not perfect?

Question 35

Given a strand of DNA that "reads" GATTACGATT, what would the sequence of bases on the opposite side "read"?