Deck 12: DNA: The Molecule of Heredity

Question 1

In a DNA molecule, base pairing occurs between

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

Answer 1

A

Question 2

The ʹruleʺ formulated by Chargaff states that

A) A = G and C = T in any molecule of DNA.
B) A = T and G = C in any molecule of DNA.
C) A = U and G = C in any molecule of RNA.
D) A = C and G = T in any molecule of DNA.
E) DNA and RNA are made up of the same four nitrogenous bases.

Answer 2

B

Question 3

In Griffithʹs experiments, what happened when heat-killed S-strain bacteria were injected into a mouse along with live R-strain bacteria?

A) Proteins released from the heat-killed S-strain killed the mouse.
B) DNA from the heat-killed S-strain was taken up by the live R-strain, converting them to S-strain and killing the mouse.
C) RNA from the heat-killed S-strain was translated into proteins that killed the mouse.
D) DNA from the live R-strain was taken up by the heat-killed S-strain, converting them to R-strain and killing the mouse.

Answer 3

B

Question 4

In DNA, phosphate groups bond to

A) pyrimidine bases.
B) other phosphate groups.
C) adenine.
D) deoxyribose.
E) ribose.

Question 5

If the DNA of a certain organism has guanine as 30% of its bases, then what percentage of its bases are adenine?

A) 0%
B) 10%
C) 40%
D) 30%
E) 20%

Question 6

All of the following are found in DNA EXCEPT

A) thymine.
B) a phospholipid group.
C) deoxyribose.
D) a phosphate group.
E) guanine.

Question 7

A DNA nucleotide is made up of

A) phosphate-deoxyribose-base.
B) phosphate-deoxyribose-phosphate-deoxyribose.
C) adenine-thymine-guanine-cytosine.
D) base-phosphate-glucose.
E) phospholipid-deoxyribose-base.

Question 8

Hershey and Chase concluded that__________ is the hereditary molecule by examining how radioactively labeled molecules moved between a virus and bacteria.

A) Lipids
B) phospholipids
C) protein
D) DNA

Question 9

Complementary base pairs are held together by

A) hydrogen bonds.
B) covalent bonds.
C) disulfide bonds.
D) ionic bonds.
E) peptide bonds.

Question 10

ʺChargaffʹs ruleʺ for base pairing in DNA is that

A) A bonds with C, and G bonds with T.
B) A bonds with G, and C bonds with T.
C) A bonds with T, and G bonds with C.
D) the amount of A = the amount of C, and the amount of G = the amount of T.
E) the amount of A = the amount of G, and the amount of C = the amount of T.

Question 11

By the early 1950s, many biologists realized that the key to understanding inheritance lay in the structure of

A) DNA.
B) ribosomes.
C) chromosomes.
D) protein.
E) enzymes.

Question 12

The X-ray diffraction pattern for DNA suggested to Wilkins and Franklin all of the following features about DNA EXCEPT

A) a DNA molecule has a uniform diameter of 2 nanometers.
B) in a DNA molecule, A pairs with T and G pairs with C.
C) the DNA molecule consists of repeating subunits.
D) the phosphate-sugar ʺbackboneʺ of the molecule is on the outside of the DNA helix.
E) a DNA molecule is helical.

Question 13

The two polynucleotide chains in a DNA molecule are attached to each other by

A) hydrogen bonds between bases.
B) ionic bonds between ʺRʺ groups in amino acids.
C) peptide bonds between amino acids.
D) covalent bonds between phosphates and sugars.
E) covalent bonds between carbon atoms.

Question 14

When Griffith experimented with two types of Streptococcus pneumoniae, he found that if the

A) deadly strain was heat-killed before injection, the mice died.
B) non-deadly strain was mixed with the heat -killed, deadly strain before injection, the mice died.
C) non-deadly strain was mixed with the heat -killed, deadly strain before injection, the mice lived.
D) non-deadly strain was mixed with the heat -killed, non-deadly strain before injection, the mice died.

Question 15

What was the most significant conclusion of Griffithʹs experiments with pneumonia in mice?

A) Mice exposed to the S-strain bacterium became resistant to the R-strain bacterium.
B) S-strain bacteria can cause pneumonia.
C) Heat destroys the hereditary material.
D) There is a substance present in dead bacteria that can cause a heritable change in living bacteria.
E) The genetic material was definitively proven to be DNA.

Question 16

What is the relationship among DNA, a gene, and a chromosome?

A) A gene contains hundreds of chromosomes, which are composed of protein.
B) A gene is composed of DNA, but it has no relationship to a chromosome.
C) A chromosome contains hundreds of genes, which are composed of DNA.
D) A chromosome contains hundreds of genes, which are composed of protein.
E) A gene contains hundreds of chromosomes, which are composed of DNA.

Question 17

If the quantities of the four bases in a DNA molecule are measured, we find that

A) A = C and G = T.
B) T = A and C = G.
C) A = G and C = T.
D) no two bases are equal in amount.
E) all bases are equal in amount.

Question 18

The hereditary material present in all cells is

A) RNA.
B) R-strain.
C) S-strain.
D) protein.
E) DNA.

Question 19

DNA possesses

A) C, T, A, and G bases.
B) only C and T bases.
C) A, U, G, and C bases.
D) only U and T bases.
E) only A and G bases.

Question 20

The sequence of subunits in the DNA ʺbackboneʺ is

A) -sugar-base-sugar-base-sugar-base-sugar-base-.
B) -phosphate-sugar-phosphate-sugar-phosphate-sugar-.
C) -base-phosphate-sugar-base-phosphate-sugar-.
D) -base-phosphate-base-phosphate-base-phosphate-.
E) -base-sugar-phosphate-base-sugar-phosphate-.

Question 21

Which component of a DNA nucleotide could be removed without breaking the polynucleotide chain?

A) Phosphate
B) Deoxyribose
C) Ribose
D) Nitrogen base

Question 22

It became apparent to Watson and Crick after completing their model that a DNA molecule could carry a vast amount of hereditary information in its

A) variety of phosphate groups.
B) sequence of bases.
C) side groups of bases.
D) phosphate-sugar backbone.
E) different five-carbon sugars.

Question 23

Which of the following is TRUE regarding the genetic information in the cells of your body?

A) Different kinds of body cells contain different genetic information.
B) The genetic information in almost all of your body cells is identical.
C) The genetic information in your body cells changes in a predictable manner as you grow and develop.
D) Each type of body cell contains only the genetic information it needs to be that type of cell.

Question 24

Regarding the structure of DNA, which of the following joins adenine and thymine and also guanine and cytosine?

A) Phosphate
B) Double helix
C) Covalent bonds
D) Deoxyribose
E) Hydrogen bonds

Question 25

In the comparison of a DNA molecule to a twisted ladder, the rungs (footholds) of the ladder are

A) the backbones of the molecule.
B) deoxyribose linked to phosphate.
C) nitrogenous bases linked together.
D) deoxyribose linked to sulfate.
E) nitrogenous bases linked to phosphate.

Question 26

The way DNA stores information is through the__________ of bases.

A) number
B) different types
C) sequence
D) size

Question 27

Regarding the structure of DNA, which of the following is like a spiral staircase?

A) Phosphate
B) Hydrogen bonds
C) Deoxyribose
D) Double helix
E) Covalent bonds

Question 28

How many bases are in the DNA molecule of a typical human chromosome?

A) Two
B) Millions
C) Four
D) Thousands

Question 29

How many different kinds of nucleotides are in DNA?

A) Four
B) Millions
C) Hundreds or thousands
D) Two

Question 30

Which of the following is NOT true according to Chargaffʹs base pairing rule?

A) A + T = G + C in amount.
B) A = T in amount.
C) A + G = T + C in amount.
D) G = C in amount.

Question 31

Regarding the structure of DNA, which of the following joins deoxyribose to phosphate?

A) Phosphate
B) Double helix
C) Covalent bonds
D) Hydrogen bonds
E) Ionic bonds

Question 32

Watson and Crick are credited with the discovery and description of the DNA

A) deoxyribose sugar.
B) double helix.
C) phosphate group.
D) covalent bonds.
E) hydrogen bonds.

Question 33

If the DNA sequence is G-C-C-T-A-T in one polynucleotide chain, then the sequence found in the other polynucleotide chain must be

A) G-C-C-T-A-T.
B) C-G-G-A-T-A.
C) A-T-T-C-G-C.
D) C-G-G-A-U-A.
E) G-C-C-A-T-A.

Question 34

When a cell divides, each daughter cell receives

A) exactly half the genetic information in the parent cell.
B) twice the amount of genetic information of the parent cell.
C) a nearly perfect copy of the parent cellʹs genetic information.
D) the same amount of genetic information that was in the parent cell, but it has been altered.

Question 35

Regarding the structure of DNA, the units that form the ʺuprightsʺ (sides) of the DNA ladder and do not attach to the nitrogen bases are

A) phosphate molecules.
B) sulfur-containing bases.
C) ribose molecules.
D) deoxyribose molecules.

Question 36

How many different kinds of base pairings are in DNA?

A) Millions
B) Two
C) Hundreds or thousands
D) Four

Question 37

Regarding the structure of DNA, which of the following is covalently bonded to a nitrogen base?

A) Phosphate
B) Phospholipid
C) Deoxyribose
D) Hydrogen bonds
E) Ribose

Question 38

When DNA polymerase encounters thymine in the parental strand, what does it add to the growing daughter strand?

A) Adenine
B) Uracil
C) Deoxyribose
D) Phosphate group

Question 39

In the comparison of a DNA molecule to a twisted ladder, the upright sides of the ladder are

A) hydrogen bonds between bases.
B) nitrogenous bases linked to phosphate.
C) deoxyribose linked to phosphate.
D) deoxyribose linked to sulfate.
E) nitrogenous bases linked together.

Question 40

Which of the following is TRUE in the Watson-Crick model of DNA?

A) Ribose always bonds to a nitrogenous base.
B) Four different types of bases are found in DNA.
C) Phosphate groups always bond to ribose.
D) During replication, the phosphate groups are copied but the base sequence is not copied.
E) The number of adenines equals the number of guanines.

Question 41

Specific segments of DNA that code for a specific protein are called

A) nucleoli.
B) nuclei.
C) genes.
D) chromosomes.
E) mutations.

Question 42

Imagine that a DNA sequence of 5ʹ-A-C-G-T-A-C-G-T-3ʹ is altered to 5ʹ-A-C-G-A-C-G-T-3ʹ. This could happen as a result of a(n)

A) deletion mutation.
B) translocation.
C) insertion mutation.
D) inversion.
E) nucleotide substitution mutation.

Question 43

Which of the following is NOT involved in the DNA replication process?

A) DNA helicase
B) DNA polymerase
C) DNA replicase
D) DNA ligase

Question 44

A cell that lacks the ability to make DNA repair enzymes will

A) be unable to replicate its DNA.
B) replicate its DNA as well as a cell with intact repair enzymes.
C) be able to correctly replicate its DNA, but it will need more time to do so.
D) replicate its DNA as rapidly as a normal cell, but the resulting DNA will have more errors in it.

Question 45

DNA polymerase always moves from__________ along the strand resulting in DNA replication to be continuous on one strand and discontinuous on the other.

A) base to phosphor group
B) phosphate group to base
C) 5? to 3?
D) 3? to 5?

Question 46

Which of the following is TRUE regarding how the DNA in your bodyʹs cells can accumulate mutations?

A) Spontaneous mutation rates are around one in every four nucleotides that are replicated.
B) Mistakes are never made during DNA replication; they always occur during the G1 phase of interphase.
C) Some DNA spontaneously breaks down every second, making the chromosome significantly shorter with every passing day.
D) The ultraviolet radiation in sunlight may induce changes in DNA.

Question 47

Semiconservative DNA replication means that

A) A pairs with T and G pairs with C.
B) the old DNA remains completely intact.
C) each new DNA molecule has half the DNA from the old one.
D) the old DNA is completely broken down.
E) only half of the DNA is replicated.

Question 48

In one strand of DNA, the nucleotide sequence is 5ʹ-A-T-G-C-3ʹ. The complementary sequence in the other strand must be

A) 5ʹ-A-T-G-C-3ʹ.
B) 5ʹ-C-G-T-A-3ʹ.
C) 3ʹ-T-A-C-G-5ʹ.
D) 3ʹ-G-C-A-T-5ʹ.

Question 49

What determines the function of the gene product?

A) The sequence of bases
B) The number of bases
C) The sequence of phosphates
D) The sequences of deoxyribose
E) The number of phosphates

Question 50

Imagine that a DNA sequence of 5ʹ-A-C-G-T-A-C-G-T-3ʹ is altered to 5ʹ-A-C-G-C-A-C-G-T-3ʹ. This could happen as a result of a(n)

A) insertion mutation.
B) deletion mutation.
C) translocation.
D) nucleotide substitution mutation.
E) inversion.

Question 51

Agents that cause mutations are called mutagens. All of the following are examples of mutagens EXCEPT

A) vitamins.
B) X-rays.
C) ultraviolet radiation.
D) cigarette smoke.

Question 52

What two bases in the DNA molecule are double-ringed?

A) Guanine and cytosine
B) Thymine and cytosine
C) Guanine and adenine
D) Uracil and guanine
E) Thymine and uracil

Question 53

Which of the following is TRUE about the accuracy of DNA replication?

A) Many errors are made during DNA replication, but this does not matter because repair enzymes mend the errors.
B) DNA polymerase makes very few errors, so no repair enzymes are needed.
C) The few errors made by DNA polymerase are usually corrected by repair enzymes.
D) DNA polymerase always makes a perfect copy of the original DNA.
E) Many errors are made during DNA replication, but this does not matter because of the immense size of the DNA molecule.

Question 54

__________replication is the process when DNA uses one parental strand and synthesizes a new strand, resulting in each daughter cell having a new and parental DNA strand.

A) Redundant
B) Inversion
C) Conservative
D) Semiconservative

Question 55

A(n) __________mutation is when one or more nucleotide pairs are lost.

A) deletion
B) nucleotide substitution
C) inversion
D) insertion

Question 56

After proofreading repair enzymes check the work of DNA polymerase, newly replicated DNA strands contain about one mistake for every

A) 100 million to 10 billion base pairs.
B) 10,000 to 1 million base pairs.
C) 1 million to 10 million base pairs.
D) 1 to 100 base pairs.
E) 100 to 1,000 base pairs.

Question 57

All of the following occur during DNA replication EXCEPT

A) use of DNA polymerase enzymes.
B) synthesis of totally new double-stranded DNA molecules.
C) separation of parental DNA strands.
D) use of parental DNA as a template.

Question 58

Mutations are a source of genetic__________ by which evolutionary change is possible.

A) reproduction
B) variability
C) stability
D) constancy

Question 59

DNA polymerase, before any proofreading by repair enzymes, makes one mistake for about every

A) 10,000 to 1 million base pairs.
B) 100 million to 10 billion base pairs.
C) 1 to 100 base pairs.
D) 100 to 1,000 base pairs.
E) 1 million to 10 million base pairs.

Question 60

When chromosomes replicate

A) the two DNA strands separate and each is used as a template for synthesis of a new strand.
B) new DNA synthesis occurs in only one location along the entire DNA molecule.
C) the original DNA is distributed to the two daughter cells, with no new DNA synthesized.
D) one strand of the DNA is completely replicated first, and then the second strand is replicated.

Question 61

At one end of a double helix, one strand has a free sugar (3?) group and the other strand has a free__________ group.

Question 62

DNA__________ breaks the hydrogen bonds between complementary base pairs during DNA replication.

Question 63

The basic subunits of DNA are the__________ .

Question 64

The DNA of chromosomes is composed of two strands wound about each other in the shape of a __________.

Question 65

Most mutations are harmful or neutral, although in rare instances some can be beneficial.

Question 66

DNA ligase is important in the replication process because it can join together segments of DNA into a single daughter strand.

Question 67

Chargaff found that the amounts of the four bases vary from species to species, but the amount of adenine always equals the amount of guanine and the amount of thymine always equals the amount of cytosine.

Question 68

In eukaryotic cells, chromosomes are composed of both DNA and proteins.

Question 69

DNA replication occurs without errors due to the complementary base pairing used in the copying process.

Question 70

The X-ray diffraction studies of the scientists named __________and __________were essential for the discovery of the structure of the DNA molecule.

Question 71

The two strands of DNA are held together by hydrogen bonds.

Question 72

DNA polymerase has the ability to match the nucleotide base in the parental strand with a free nucleotide that is complementary to that base. It then forms the covalent bonds between the nucleotides in the growing daughter strand of DNA.

Question 73

In semiconservative replication, a DNA molecule serves as a template for a new DNA molecule, which consists of either both parental strands of DNA or both newly synthesized strands of DNA.

Question 74

During DNA replication, the continuous daughter strand is the leading strand.

Question 75

The number of subunits in a DNA molecule is more important to its function than the sequence of these subunits.

Question 76

Inversions are movements of DNA from one chromosome to another.

Question 77

DNA helicase is involved in ʺrewindingʺ the strands of DNA back into a helix after replication.

Question 78

Chromosomes contain both __________and__________ , and early -20th-century scientists were unsure which of these molecules carried the heritable units called genes.

Question 79

The molecule__________ carries the genetic ?blueprints? for all forms of life on Earth.

Question 80

By the early 1900s, scientists had determined that heritable information existed as discrete units called genes, which were located on__________ .