Deck 8: What Genes Are

Question 1

When bases of DNA bind to the complementary strand

A)A always pairs with T.
B)A sometimes pairs with T.
C)A always pairs with C.
D)A sometimes pairs with C.

Answer 1

A

Question 2

If a segment of double-stranded DNA has 20 percent A,how much of it is C?

A)20 percent
B)30 percent
C)40 percent
D)60 percent

Answer 2

B

Question 3

In a strand of double-stranded DNA,C will always be bound with

A)A.
B)T.
C)C.
D)G.

Answer 3

D

Question 4

This figure shows a short sequence of DNA.During DNA replication,the piece of DNA depicted in this figure will produce

A)one single-stranded molecule with the sequence CAGT.
B)two single-stranded molecules with the sequence GTCA.
C)one single-stranded molecule with the sequence CAGT and a separate single-stranded molecule with the sequence GTCA.
D)two double-stranded molecules that look just like the figure.

Question 5

The order of the base pairs in a DNA molecule

A)differs from species to species.
B)is identical in all organisms.
C)is identical in organisms of the same species.
D)differs from cell to cell in a given organism.

Question 6

DNA replication

A)involves the copying of only the parts of a chromosome that encode protein.
B)occurs before mitosis in the cell cycle.
C)is constantly occurring in all the cells in your body.
D)converts the double helix to two single helices.

Question 7

What part of a nucleotide accounts for the genetic variation between individuals?

A)sugar
B)phosphate
C)base
D)polymerase

Question 8

When examining the two complementary strands of nucleotides in one DNA molecule,you would expect to find that

A)the sum of Gs and Cs in one strand would be equal to the sum of the Gs and Cs in the other strand.
B)the sum of Ts and As in one strand would be equal to the sum of the Cs and Gs in the other strand.
C)the sum of Ts and As in one strand would be greater than the sum of the Ts and As in the other strand.
D)the sum of As and Cs in one strand would be less than the sum of the Ts and Gs in the other strand.

Question 9

The significance of specific base pairing in DNA is that

A)it stabilizes the sugar molecule.
B)it provides a method for making exact copies of DNA.
C)it prevents errors in DNA replication.
D)protein copies can be made directly from the DNA.

Question 10

How many phosphate groups are present in a single strand of DNA?

A)the same number as there are adenine bases
B)the same number as there are adenine + thymine bases
C)the same number as there are guanine + cytosine bases
D)the same number as there are adenine + thymine + guanine + cytosine bases

Question 11

When a cell divides,it

A)breaks down its DNA.
B)deletes old genetic information.
C)copies information from neighboring cells.
D)copies its own genetic information.

Question 12

The two strands of a DNA molecule are held together by ________ bonds between their base pairs.

A)hydrogen
B)amino acid
C)phosphate
D)protein

Question 13

If one strand of DNA has the sequence CGATT,the sequence of the other strand of the same molecule will be

A)CGATT.
B)GCTUU.
C)TACGG.
D)GCTAA.

Question 14

Once replication in a DNA molecule is complete,each new DNA molecule contains

A)one old strand and one new strand.
B)the paired old strands and the paired new strands.
C)new DNA polymerase.
D)a new sequence of nucleotides.

Question 15

The sequence of DNA differs among individuals within a species.This is the basis for

A)mutation.
B)protein structure.
C)base pairing.
D)variations in phenotypes.

Question 16

The hereditary genetic material present in all living cells is

A)carbohydrate.
B)protein.
C)DNA.
D)RNA.

Question 17

Along one side of a DNA molecule,the nucleotides are connected to each other by

A)covalent bonds between phosphate groups and sugar molecules.
B)hydrogen bonds between adenine and guanine.
C)covalent bonds between bases and sugar molecules.
D)hydrogen bonds between adjacent sugar molecules.

Question 18

When looking at a single-stranded piece of DNA,

A)G will always be next to C.
B)G will always be next to G.
C)G will sometimes be next to T.
D)G will never be next to A.

Question 19

Which of the following is not a base found in DNA?

A)thymine
B)adenine
C)guanine
D)uracil

Question 20

Replication of DNA cannot begin until

A)phosphate bonds between nucleotides are broken.
B)hydrogen bonds between complementary bases are broken.
C)covalent bonds between sugar molecules are broken.
D)hydrogen bonds between nucleotides in one strand are broken.

Question 21

The following figure illustrates DNA undergoing replication.The region indicated by the arrow in this image represents a

A)single base pair.
B)mismatch error.
C)mutation.
D)transformation.

Question 22

A scientist uses polymerase chain reaction (PCR)to compare the sequence of a disease and a healthy gene.The scientist finds that these two genes are identical except for one G in place of a T at position 256 in the gene.This type of mutation is a(n)

A)deletion.
B)insertion.
C)silent mutation.
D)substitution mutation.

Question 23

What would be the result if DNA polymerase did not have the ability to proofread?

A)DNA replication would not proceed at all.
B)DNA replication would proceed more slowly.
C)DNA replication would result in more mutations.
D)DNA replication would result in additional copies of DNA.

Question 24

A segment of DNA in a test tube replicates and produces many copies of itself.What was probably in the test tube that enhanced this process?

A)repair enzymes
B)polymerase
C)plasmids
D)a mutagen

Question 25

Which of the following must occur for a mismatch error to be repaired?

A)DNA repair proteins identify damaged DNA.
B)The sequence of nucleotides in the damaged DNA sequence guides the synthesis of the correct DNA sequence.
C)DNA-eating enzymes within the nucleus destroy entire strands of damaged DNA.
D)The damaged DNA undergoes DNA replication one more time.

Question 26

DNA fingerprinting is based on regions of DNA that are variable between individuals.Many of these differences between individuals produce no change in phenotype.This type of mutation is a(n)

A)deletion.
B)insertion.
C)silent mutation.
D)substitution mutation.

Question 27

The adenine bases in a DNA molecule are radioactively labeled.The DNA is then placed in a solution containing unlabeled nucleotides and the enzymes needed for DNA replication.The DNA molecule is allowed to replicate twice,forming four new DNA molecules.You would find the radioactively labeled adenine in

A)each of the eight strands.
B)two of the eight strands.
C)all but one strand.
D)six of the eight strands.

Question 28

A rapidly dividing cell is exposed to a chemical that converts the bond that forms between adenine and thymine to a covalent bond.Which of the following is most likely to occur?

A)DNA replication would produce two molecules of DNA with mutations at every base that once held an A-T base pair.
B)DNA replication would not occur because the two nucleotide strands that make up the DNA molecule would not be able to separate.
C)DNA replication would occur more slowly because DNA repair proteins would have to fix the covalent bonds before replication could begin.
D)DNA replication would be faster because covalent bonds require less energy to break than hydrogen bonds.

Question 29

The polymerase chain reaction (PCR)technique could be developed only after the discovery of bacterial enzymes that were able to withstand high temperatures.Why was it necessary to use such enzymes?

A)Only bacterial DNA can be copied using the PCR method,so bacterial enzymes were necessary.
B)Bacterial enzymes can bind to DNA outside of a cell.
C)DNA can be cut into fragments only at high temperatures.
D)The temperature required to separate DNA strands during PCR degrades most normal enzymes.

Question 30

DNA polymerase is used in the laboratory to

A)perform gel electrophoresis procedures.
B)cure patients of certain genetic diseases.
C)make many copies of a DNA sequence.
D)attach DNA fragments to each other.

Question 31

Damaged DNA may be repaired by a special class of

A)nucleotides.
B)proteins.
C)deoxyribose molecules.
D)phosphate bonds.

Question 32

The DNA primers used in polymerase chain reaction (PCR)are

A)identical to the entire base sequence of one strand of the DNA.
B)produced when a gene of interest is read by restriction enzymes.
C)attached to the gene of interest by polymerase.
D)complementary to DNA sequences at both ends of the DNA sequence of interest.

Question 33

Mismatch errors are

A)almost always corrected by mutagens.
B)also called mutations.
C)almost always corrected by specialized proteins.
D)usually caused by mutated proteins.

Question 34

Is a species that lacks DNA repair mechanisms likely to have more or fewer variations between individuals than a species that possesses repair mechanisms?

A)fewer,because there are fewer ways to change the DNA
B)fewer,because the repair mechanisms introduce more variation into the DNA sequence
C)more,because more spontaneous mutations will go uncorrected
D)more,because without a repair mechanism,the cell's DNA replication genes are inactivated

Question 35

The following figure shows the first cycle in polymerase chain reaction (PCR).What is the role of the structure marked "P" in this figure?

A)The "P" represents the heat-tolerant DNA polymerase used in PCR to copy the gene of interest.
B)The "P" represents a sequence of DNA complementary to parts of the gene being amplified that allows DNA polymerase to attach to the gene.
C)The "P" indicates where on the DNA that DNA polymerase should terminate replication.
D)The "P" indicates the location of the promoter for the gene being amplified.

Question 36

A detective finds a miniscule spot of blood on a murder suspect's shirt.What method would she expect the police lab to use to get enough DNA from the blood droplet to perform DNA fingerprinting?

A)inserting the blood's DNA into viral DNA
B)polymerase chain reaction (PCR)
C)inserting the sample's DNA into a plasmid
D)DNA sequencing

Question 37

The difference between the different alleles of a gene is

A)their DNA base sequences.
B)the way they are copied when the cell divides.
C)the type of lipid they are composed of.
D)they are not heritable.

Question 38

Which of the following will NOT generally cause mutations?

A)chemicals
B)radiation
C)viruses
D)DNA replication

Question 39

The polymerase chain reaction (PCR)is used to

A)produce many copies of a selected DNA sequence.
B)insert DNA from one organism into a new host.
C)screen for a particular gene.
D)deliver DNA products into a human patient.

Question 40

A permanent change in the DNA base sequence due to an uncorrected mismatch error is called a(n)

A)mutation.
B)replication.
C)repair protein.
D)insertion.

Question 41

MATCHING
Put the following in order from smallest to largest.
a.gene
b.base
c.nucleotide
d.genome
e.base pair
This is the smallest in size.

Question 42

A protein binds to the outside of a DNA strand.This protein does NOT likely bind to the ________ of the DNA nucleotides.

Question 43

A scientist is interested in studying the mechanism of horizontal gene transfer.

A)The scientist should select a prokaryotic cell.
B)The scientist should select a eukaryotic cell.
C)The scientist can select either a prokaryotic or a eukaryotic cell.
D)The scientist will need to design a novel cell using DNA sequencing.

Question 44

A scientist identifies a new cell with a single chromosome that is able to do gene transfer.

A)This cell will likely be classified as a eukaryotic cell.
B)This cell will likely be classified as a prokaryotic cell.
C)This cell cannot be classified as either prokaryotic or eukaryotic.
D)This cell will likely be classified as both prokaryotic and eukaryotic.

Question 45

Which of the following does NOT correctly state a difference between prokaryotic and eukaryotic DNA organization?

A)Prokaryotic DNA groups genes with related functions together,whereas eukaryotic DNA does not.
B)Prokaryotic DNA has few noncoding regions,unlike eukaryotic DNA.
C)Eukaryotic DNA is usually arranged more simply than prokaryotic DNA.
D)Eukaryotic genomes contain more genes than prokaryotic genomes.

Question 46

Being in the sun for short stretches of time is not as likely to cause mutations as is being in the sun for long stretches of time.Explain why longer exposure to UV is more likely to cause mutations.

Question 47

Are mutations always harmful? Justify your answer and give an example to support your answer.

Question 48

In the first step of the polymerase chain reaction (PCR),the two strands of the DNA being amplified must be separated by exposing the DNA to high ________.

Question 49

When studying genomes of organisms,scientists often will only list the sequence of a single strand.Explain why the sequence of the second strand would be unnecessary information.

Question 50

Animal genes are not turned on and off as one unit because they are not ________.

Question 51

A scientist adds a single polymerase and primer to a polymerase chain reaction (PCR)but does not add nucleotides.How many strands would be present after three replications if a single original strand was present? Explain your answer.

Question 52

It can be said that prokaryotic genomes are more efficient than eukaryotic genomes.Refute or support this claim using evidence.

Question 53

A chemical that disrupts hydrogen bonds is added to a test tube containing DNA.What would be the result of this reaction?

Question 54

People with xeroderma pigmentosum frequently exhibit skin cancer.The disease is a result of a mutation in a gene that produces a ________ protein.Without this protein,cells cannot fix changes in their DNA sequence caused by exposure to ultraviolet (UV)light.

Question 55

A strand of DNA has the sequence GCAATTCG.The sequence of the complementary strand is ________.

Question 56

The enzyme that copies DNA is called ________.

Question 57

Which of the following is true of eukaryotic genomes?

A)They consist of a single chromosome.
B)Most of the DNA codes for proteins.
C)Genes are organized by function.
D)The DNA is in the nucleus of the cell.

Question 58

A chemical is found that binds to a replicating strand of DNA but does not allow the next nucleotide to bind to the growing chain.Explain how this chemical would affect cell division.

Question 59

Most eukaryotic DNA is

A)single-stranded.
B)noncoding.
C)regulatory sequences.
D)prokaryotic.

Question 60

A mutation is due to the addition of two bases in a strand of DNA.This is called a(n)________.

Question 61

MATCHING
Put the following in order from smallest to largest.
a.gene
b.base
c.nucleotide
d.genome
e.base pair
This is the next larger.

Question 62

MATCHING
Put the following in order from smallest to largest.
a.gene
b.base
c.nucleotide
d.genome
e.base pair
This is the largest.

Question 63

MATCHING
Put the following in order from smallest to largest.
a.gene
b.base
c.nucleotide
d.genome
e.base pair
This is the next larger.

Question 64

MATCHING
Put the following in order from smallest to largest.
a.gene
b.base
c.nucleotide
d.genome
e.base pair
This is the next larger.