Chapter 12 (Test 3)

Question 1

Early researchers knew that the genetic material must be 
able to (blank) information used to control the (blank, blank, blank)

Answer 1

store; development, structure, and metabolic activities of

cells

Question 2

Early researchers knew that the genetic material must be (blank) so it can be (blank) accurately during cell division and be transmitted from generation to generation;

Answer 2

stable; replicated

Question 3

Early researchers knew that the genetic material must be able to undergo (blank) providing the (blank) required for evolution.

Answer 3

mutations; genetic variability

Question 4

Bacteriologist (blank) (1931) experimented with Streptococcus pneumoniae (a pneumococcus that causes pneumonia in mammals).

Answer 4

Frederick Griffith

Question 5

Mice were injected with two strains of (blank): an encapsulated (S) strain and a non-encapsulated (R) strain.

Answer 5

pneumococcus

Question 6

The (blank) strain is virulent (the mice died); it has a mucous capsule and forms “shiny” colonies.
The (blank) strain is not virulent (the mice lived); it has no capsule and forms “dull” colonies.

Answer 6

S; R

Question 7

In an effort to determine if the (blank) alone was responsible for the virulence of the S strain, he injected mice with heat-killed S strain bacteria; the mice lived.

Answer 7

capsule

Question 8

Finally, he injected mice with a mixture of heat-killed (blank) strain and live (blank) strain bacteria.

Answer 8

S; R

Question 9

The mice died; living (blank) strain pneumococcus was recovered from their bodies.
Griffith concluded that some substance necessary for synthesis of the (blank)—and therefore for virulence—must pass from dead (blank) strain bacteria to living (blank) strain bacteria so the R strain were transformed.
This change in (blank) of the R strain must be due to a change in the bacterial (blank), suggesting that the transforming substance passed from S strain to R strain.

Answer 9

S; capsule; S; R; phenotype; genotype

Question 10

Oswald Avery et al. (1944) reported that the transforming substance was (blank)

Answer 10

DNA

Question 11

In the early twentieth century, it was shown that nucleic acids contain four types of (blank)

Answer 11

nucleotides

Question 12

DNA is composed of repeating units, each of which always had just one of each of four different nucleotides:

Answer 12

a nitrogenous base, a phosphate, and a pentose

Question 13

Purified DNA is capable of bringing about the (blank)

Answer 13

transformation

Question 14

DNA from S strain pneumococcus causes R strain bacteria to be (blank)

Answer 14

transformed;

Question 15

(blank) of the transforming substance with an enzyme that digests DNA (DNase) prevents transformation.

Answer 15

Digestion

Question 16

The molecular weight of the transforming substance is great enough for some (blank)

Answer 16

genetic variability

Question 17

Enzymes that (blank) proteins cannot prevent transformation, nor can enzymes that digest (blank)

Answer 17

degrade; RNA (RNase).

Question 18

Avery’s experimental results demonstrated DNA is (blank) and DNA controls (blank) of a cell.

Answer 18

genetic material; biosynthetic properties

Question 19

In order to illustrate that transferring genes was possible from one organism to another, scientists used a green fluorescent (blank) from jellyfish and transferred it to other organisms. The result was that these organisms

Answer 19

protein; glowed in the dark

Question 20

Mammalian genes have the ability to function in other species:

Answer 20

bacteria, invertebrates, plants.

Question 21

(blank) (1940s) analyzed the base content of DNA.

Answer 21

Erwin Chargaff

Question 22

DNA contained four different nucleotides:
Two with (blank) bases, adenine (A) and guanine (G); a type of nitrogen-containing base having a (blank) structure.
Two with (blank) bases, thymine (T) and cytosine (C); a type of nitrogen-containing base having a (blank) structure.
Results:

Answer 22

purine; double-ring; pyrimidine; single-ring

DNA does have the variability necessary for the genetic material.

Question 23

For a species, DNA has the (blank) required of genetic material.
This is given in Chargaff’s rules:
The amount of A, T, G, and C in DNA varies from species to species.
In each species, the amount of (blank) and the amount of (blank)

Answer 23

constancy; A = T; G = C

Question 24

(blank) produced X-ray diffraction photographs.

His/her work provided evidence that DNA had the following features:

Answer 24

Rosalind Franklin; DNA is a helix & Some portion of the helix is repeated.

Question 25

American (blank) joined with (blank) in England to work on the structure of DNA. They received the (blank) in 1962 for their model of DNA.

Answer 25

James Watson; Francis H. C. Crick; Nobel Prize

Question 26

``` Using information generated by Chargaff and Franklin, Watson and Crick constructed a model of DNA as a (blank) with (blank) groups on the outside, and (blank) on the inside. Their model was consistent with both (blank)'s rules and Franklin’s (blank) studies. ```

Answer 26

double helix; sugar-phosphate; paired bases; Chargaff; X-ray diffraction

Question 27

(blank) is the process of copying a DNA molecule.

Answer 27

DNA replication

Question 28

Replication is (blank), with each strand of the original double helix (parental molecule) serving as a (blank) (mold or model) for a new strand in a daughter molecule.

Answer 28

semiconservative; template

Question 29

DNA replication contains what processes?

Answer 29

unwinding, Complementary base pairing, Joining

Question 30

old strands of the parent DNA molecule are unwound as weak hydrogen bonds between the paired bases are “unzipped” and broken by the enzyme helicase. Process?

Answer 30

unwinding

Question 31

free nucleotides present in the nucleus bind with complementary bases on unzipped portions of the two strands of DNA; this process is catalyzed by (blank) Process?

Answer 31

Complementary base pairing; DNA polymerase

Question 32

complementary nucleotides bond to each other to form new strands; each daughter DNA molecule contains an old strand and a new strand; this process is also catalyzed by (blank) Process?

Answer 32

Joining; DNA polymerase

Question 33

For complementary base pairing to occur, the DNA strands need to be (blank)

Answer 33

antiparallel

Question 34

One strand of DNA is (blank) at the top and the other strand is (blank) at the top of the strand.

Answer 34

5' | 3'

Question 35

During replication the (blank) can only join to the free 3’ end of the previous (blank)

Answer 35

DNA polymerase; nucleotide

Question 36

DNA polymerase cannot start the synthesis of a DNA chain, so an (blank) lays out an (blank) that is complementary to the replicated strand. Now the (blank) can join the DNA nucleotides to the (blank) end of the new strand.

Answer 36

RNA polymerase; RNA primer; DNA polymerase; 3'

Question 37

The (blank) unwinds the DNA and one strand (called the (blank)) can be copied in the direction of the (blank) The other strand of DNA is copied in the direction (blank) from the fork, and replication begins again. This new lagging strand is discontinuous and each segment is called an (blank), after the scientist who discovered them.

Answer 37

helicase enzyme; leading new strand; replication fork; away | Okazaki fragment

Question 38

Replication is only complete when (blank) are removed.

Answer 38

RNA primers During replication

Question 39

During replication, DNA molecules get

Answer 39

smaller

Question 40

The end of eukaryotic DNA molecules have nucleotide sequences called (blank)

Answer 40

telomeres.

Question 41

Telomeres don’t code for proteins. They are repeats of (blank)

Answer 41

short nucleotide sequences

Question 42

Bacteria have a (blank) of DNA that must replicate before the cell divides.

Answer 42

single loop

Question 43

Replication in prokaryotes may be (blank) from one point of origin or in only one direction.

Answer 43

bidirectional

Question 44

Replication only proceeds in one direction, from (blank)

Answer 44

5' to 3'

Question 45

Replication begins at a special site on a bacterial chromosome, called the (blank)

Answer 45

origin of replication.

Question 46

Bacterial cells can complete DNA replication (blank) than eukaryotes

Answer 46

quicker

Question 47

Replication in eukaryotes starts at many points of origin and spreads with many replication (blank)—places where the DNA strands are separating and replication is occurring.

Answer 47

bubbles

Question 48

(BLANK) are the V-shape ends of the replication bubbles; the sites of DNA replication.

Answer 48

Replication forks

Question 49

A mismatched nucleotide may occur once per 100,000 base pairs, causing a (blank) in replication.

Answer 49

pause

Question 50

(blank) is the removal of a mismatched nucleotide; DNA repair enzymes perform this function and reduce the error rate to one per billion base pairs.

Answer 50

Proofreading

Question 51

Sir Archibald Garrod (early 1900s) introduced the phrase (blank)

Answer 51

“inborn errors of metabolism.”

Question 52

Garrod proposed that inherited defects could be caused by the lack of a (blank) Knowing that enzymes are proteins, Garrod suggested a link between (blank) and (blank)

Answer 52

particular enzyme; genes and proteins.

Question 53

George Beadle and Edward Tatum proposed the (blank) based on their study of (blank)

Answer 53

“one gene, one enzyme hypothesis”; red bread mold.

Question 54

Like DNA, (blank) is a polymer of nucleotides.

Answer 54

RNA (ribonucleic acid)

Question 55

Unlike DNA, RNA is (blank)-stranded, contains the sugar (blank) and the base (blank) instead of thymine (in addition to cytosine, guanine, and adenine).

Answer 55

single; ribose, uracil

Question 56

three major classes of RNA

Answer 56

mRNA, tRNA, rRNA

Question 57

takes a message from DNA in the nucleus to ribosomes in the cytoplasm.

Answer 57

mRNA (messenger RNA)

Question 58

transfers amino acids to the ribosomes.

Answer 58

Transfer RNA (tRNA)

Question 59

along with ribosomal proteins, make up ribosomes where polypeptides are synthesized.

Answer 59

Ribosomal RNA (rRNA)

Question 60

DNA undergoes (blank) to mRNA, which is (blank) to a protein. DNA is a template for (blank) formation during transcription.

Answer 60

transcription; translated; RNA

Question 61

Transcription is the first step in gene expression; it is the process whereby a (blank) strand serves as a template for the formation of (blank)

Answer 61

DNA; mRNA

Question 62

During translation, an (blank) transcript directs the sequence of (blank) in a polypeptide.

Answer 62

mRNA; amino acids

Question 63

The process from DNA to RNA to protein to trait is the (blank) of molecular biology.

Answer 63

central dogma

Question 64

The (blank) is a triplet code, each (blank) is comprised of three nucleotide bases of DNA

Answer 64

genetic code; codon

Question 65

(blank) nucleotides based on 3-unit codons allows up to (blank) different amino acids to the specified.

Answer 65

four; 64

Question 66

Marshall Nirenberg and J. Heinrich Matthei (1961) found that a(n) (blank) that could be used to construct synthetic (blank) in a cell-free system; they showed the codon UUU coded for phenylalanine.

Answer 66

enzyme; RNA

Question 67

By translating just three nucleotides at a time, Marshall Nirenberg and J. Heinrich Matthe assigned an (blank) to each of the RNA (blank), and discovered important properties of the genetic code.

Answer 67

amino acid; codons

Question 68

The code is (blank): meaning what? this protects against potentially harmful mutations.

Answer 68

degenerate; most amino acids have more than one codon;

Question 69

The genetic code is (blank); meaning what?

Answer 69

unambiguous; each triplet codon specifies one and only one amino acid.

Question 70

The code has (blank) and (blank) signals. How many of each?

Answer 70

start and stop signals: there is one start codon and three stop codons.

Question 71

The few exceptions to the universality of the genetic code suggest the code dates back to the very first organisms and that all organisms are related (blank). Once the code was established, changes would be disruptive.

Answer 71

evolutionarily

Question 72

To start the production of mRNA, what does the DNA do?

Answer 72

the DNA double helix unwinds and unzips

Question 73

Transcription begins when (blank) attaches to a (blank) on DNA.

Answer 73

RNA polymerase; promoter

Question 74

A (blank) is a region of DNA which defines the start of the gene, the direction of transcription, and the strand to be transcribed.

Answer 74

promoter

Question 75

an enzyme that speeds formation of RNA from a DNA template

Answer 75

RNA polymerase

Question 76

Transcription: As RNA polymerase moves along the template strand of the DNA, complementary RNA (blank) are paired with DNA (blank) of the (blank) strand. The strand of DNA not being transcribed is called the (blank) strand.

Answer 76

nucleotides; nucleotides; coding; noncoding

Question 77

Transcription: RNA polymerase adds (blank) to the (blank) end of the polymer under construction. Thus, RNA synthesis is in the (blank) direction.

Answer 77

nucleotides; 3' ; 5’-to-3’

Question 78

Transcription: The RNA/DNA association is not as stable as the DNA double helix; therefore, only the newest portion of the (blank) molecule associated with (blank) is bound to DNA; the rest dangles off to the side.

Answer 78

RNA; RNA polymerase

Question 79

Transcription: Elongation of (blank) continues until (blank) comes to a stop sequence.

Answer 79

mRNA; RNA polymerase

Question 80

Transcription: The stop sequence causes RNA polymerase to stop transcribing (blank) and to release the (blank) transcript.

Answer 80

DNA; mRNA

Question 81

Transcription: Many RNA polymerase molecules work to produce (blank) from the same (blank) region at the same time.

Answer 81

mRNA; DNA

Question 82

Transcription: Cells produce thousands of copies of the same (blank) molecule and many copies of the same (blank) in a shorter period of time than if a single copy of (blank) were used to direct protein synthesis.

Answer 82

mRNA; protein; RNA

Question 83

Transcription: mRNA production: newly formed pre-mRNA transcript is processed before leaving the (blank)

Answer 83

nucleus

Question 84

Transcription: Pre-mRNA transcript is the immediate product of (blank); it contains (blank) and (blank)

Answer 84

transcription; exons and introns.

Question 85

Transcription: The ends of the (blank) molecule are altered: a (Blank) is put on the 5'; end and a (blank) is put on the 3' end.

Answer 85

mRNA; cap; poly-A tail

Question 86

Transcription: The (blank) is a modified (blank) where a ribosome attaches to begin translation.

Answer 86

cap; guanine (G)

Question 87

Transcription: The (blank) consists of a 150–200 (blank)nucleotide chain that facilitates transport of mRNA out of the nucleus and inhibits enzymatic degradation of mRNA.

Answer 87

poly-A tail; adenine (A)

Question 88

Transcription: An (blank) is a protein-coding region of the DNA code in the pre-mRNA transcript eventually expressed in the final polypeptide product.

Answer 88

exon

Question 89

Transcription: An (blank) is a non-protein coding region of DNA removed by “self-splicing” or spliceosomes before the mRNA leaves the nucleus.

Answer 89

intron

Question 90

Transcription: (blank) are enzymes made of RNA with the function of removing introns from.

Answer 90

Ribozymes

Question 91

Transcription: RNA could have served as both (blank) and as the first (blank) in early life forms.

Answer 91

genetic material; enzymes

Question 92

Transcription: (blank) contain smaller nuclear RNAs (blank). (blank) cut the pre-mRNA transcript and then rejoin adjacent exons. (blank) are capable of identifying the introns to be removed.

Answer 92

Spliceosomes; snRNAs

Question 93

Transcription: (blank) give a cell the ability to decide which exons will go in a particular mRNA.

Answer 93

Introns

Question 94

Transcription: mRNA do not have all of the possible (blank) available from a DNA sequence. What is an (blank) in one mRNA could be an (blank) in another mRNA. This process is termed (blank)

Answer 94

exons; exon; intron; alternative mRNA splicing.

Question 95

Some introns give rise to (blank) which regulate mRNA translation by bonding with mRNA through (blank) and preventing (blank) from occurring.

Answer 95

microRNAs (miRNA); complementary base pairing; translation

Question 96

(blank) shuffling occurs when introns encourage crossing over during (blank)

Answer 96

Exon; meiosis

Question 97

(blank) takes place in the cytoplasm of eukaryotic cells. It is the second step by which gene expression leads to protein synthesis.

Answer 97

Translation

Question 98

In Translation, One language (blank) is translated into another language (blank).

Answer 98

nucleic acids; protein

Question 99

Transfer RNA (tRNA) molecules transfer (blank) to the (blank)

Answer 99

amino acids; ribosomes

Question 100

The tRNA is a single-stranded ribonucleic acid that doubles back on itself to create regions where (blank) are (blank)-bonded to one another.

Answer 100

complementary bases; hydrogen

Question 101

Translation (tRNA): The (blank) binds to the 3’ end; the opposite end of the molecule contains a(n) (blank) that binds to the (blank) codon in a complementary fashion.

Answer 101

amino acid; anticodon; mRNA

Question 102

Translation (tRNA): There is at least one (blank) molecule for each of the 20 amino acids found in proteins.

Answer 102

tRNA

Question 103

Translation (tRNA): There are fewer (blank) than codons because some (blank) pair with more than one codon; if an anticodon contains a (blank) in the third position, it will pair with either an A or G—this is called the (blank)

Answer 103

tRNAs; U; wobble hypothesis

Question 104

Translation (tRNA): (blank) are amino acid-charging enzymes that recognize which amino acid should join which tRNA molecule, and covalently joins them. This requires ATP.

Answer 104

Aminoacyl-tRNA synthetases

Question 105

Translation (tRNA): An (blank) forms, which then travels to a ribosome to “transfer” its amino acid during protein synthesis.

Answer 105

amino acid–tRNA complex

Question 106

Translation (rRNA): Ribosomal RNA (rRNA) is produced from a (blank) template in the (blank) of the nucleus.

Answer 106

Ribosomal RNA (rRNA); nucleolus

Question 107

Translation (rRNA): The rRNA is packaged with a variety of (blank) into (blank) subunits, one larger than the other.

Answer 107

protein; ribosomal subunits

Question 108

Translation (rRNA): Subunits move separately through (blank) pores into the cytoplasm where they combine when (blank) begins.

Answer 108

nuclear envelope; translation

Question 109

Translation (rRNA): Ribosomes can remain in the (blank) or attach to the (blank)

Answer 109

cytoplasm; endoplasmic reticulum

Question 110

What cell contains more ribosomes? prokaryotic or eukaryotic

Answer 110

eukaryotic