Gene Expression 1

Question 1

A(n) __ can be broadly defined as a unit of heredity.

Answer 1

gene

Question 2

Gene function either at the molecular level or at the level of traits is referred to as gene __.

Answer 2

expression

Question 3

ncRNAs are RNAs that do not encode __.

Answer 3

polypeptides

Question 4

The synthesis of an RNA copy of a gene is called:

Answer 4

transcription

Question 5

DNA is ______ to produce mRNA, which is then ______ to produce proteins that determine the traits an organism expresses.

Answer 5

transcribed; translated

Question 6

A unit of heredity is also known as a(n) ______.

Answer 6

gene

Question 7

The term pre-mRNA is another name for the initial RNA ______.

Answer 7

transcript

Question 8

What term refers to gene function at the level of traits or at the molecular level?

Answer 8

Gene expression

Question 9

A gene that stores information for the production of a polypeptide is called a(n) __ gene.

Answer 9

structural

Question 10

Genes that encode polypeptides are called protein-__ genes.

Answer 10

encoding

Question 11

What is the function of mRNA?

Answer 11

It carries information from DNA to ribosomes.

Question 12

During the process of __, an RNA copy of a gene is produced.

Answer 12

transcription

Question 13

Gene expression occurs in two steps. First, the __ found in a cell is transcribed to produce __, which is then translated into __.

Answer 13

DNA, RNA, polypeptide

Question 14

The process of synthesizing a specific polypeptide on a ribosome is known as:

Answer 14

translation

Question 15

In eukaryotes, the RNA original transcript, called pre-__, must be modified in several ways to make it a functionally active mRNA.

Answer 15

mRNA

Question 16

What do structural genes store?

Answer 16

Information to specify a polypeptide

Question 17

The central dogma states that DNA is __ into mRNA, which is then __ into a polypeptide.

Answer 17

transcribed, translated

Question 18

Messenger RNA carries information from the DNA to cellular components called __, which play a key role in the synthesis of polypeptides.

Answer 18

ribsosomes

Question 19

The synthesis of an RNA copy of a gene is called:

Answer 19

transcription

Question 20

In transcription, a(n) __ sequence is copied into a(n) __ sequence.

Answer 20

DNA, mRNA

Question 21

An mRNA molecule is used to synthesize a specific polypeptide on a ribosome in the process of __.

Answer 21

translation

Question 22

At the molecular level, a gene is an organized unit of ______ sequences that can be transcribed into RNA.

Answer 22

nucleotide

Question 23

The term pre-mRNA is another name for the initial RNA ______.

Answer 23

transcript

Question 24

Which of the following are products of nonstructural genes?

• polypeptides
• pre-mRNA
• messenger RNA
• transfer RNA
• ribosomal RNA

Answer 24

transfer RNA

ribosomal RNA

Question 25

The central dogma of gene expression at the molecular level is comprised of two steps. These two steps are:

Answer 25

transcription of DNA into mRNA translation of mRNA into a polypeptide

Question 26

Transfer RNA translates the language of ______ into that of amino acids.

Answer 26

mRNA

Question 27

What is the function of mRNA?

Answer 27

It carries information from DNA to ribosomes.

Question 28

In the process of __, a DNA sequence is copied into an RNA sequence.

Answer 28

transcription

Question 29

Ribosomal RNA is a component of ribosomes, which are the sites of:

Answer 29

translation

Question 30

A gene is a unit of nucleotide sequences that enables a segment of DNA to be transcribed into __, which can then be translated to produce a polypeptide.

Answer 30

mRNA

Question 31

While the transcription of structural genes produces mRNA that specifies a polypeptide, the transcription of nonstructural genes can produce two important products: __ RNA and __ RNA.

Answer 31

transfer, ribosomal

Question 32

Which region of a structural gene signals the beginning of transcription?

Answer 32

promotor

Question 33

Transfer RNA (tRNA) is needed to make what during translation?

Answer 33

Polypeptides

Question 34

Transcription begins next to a site in DNA called the:

Answer 34

promoter

Question 35

Messenger RNA carries information from the DNA to cellular components called __, which play a key role in the synthesis of polypeptides.

Answer 35

ribosomes

Question 36

The __ is a DNA sequence that specifies the end of transcription.

Answer 36

terminator

Question 37

__ RNA forms part of the cell structure that provides the site where proteins are synthesized.

Answer 37

R

Question 38

The stages of transcription are called:

Answer 38

initiation, elongation and termination

Question 39

At the molecular level, a gene is an organized unit of ______ sequences that can be transcribed into RNA.

Answer 39

nucleotide

Question 40

During the initiation stage of bacterial transcription, the gene region called the __ functions as a recognition site for the sigma factor of RNA polymerase.

Answer 40

promoter

Question 41

Which region of a bacterial gene signals the end of transcription?

Answer 41

Terminator

Question 42

Which of the following events occur during the initiation stage of transcription? - Sigma factor is released. - DNA near the promoter is unwound to form an open complex. - RNA polymerase binds to the promoter. - The RNA transcript dissociates from the DNA.

Answer 42

DNA near the promoter is unwound to form an open complex. RNA polymerase binds to the promoter.

Question 43

The promoter of a gene signals the beginning of:

Answer 43

transcription

Question 44

What is synthesized during the elongation stage of transcription?

Answer 44

RNA

Question 45

What part of a gene signals the end of transcription?

Answer 45

Terminator

Question 46

The DNA strand that is complementary to the RNA strand produced during transcription is called the __ strand.

Answer 46

template

Question 47

Transcription occurs in three stages: initiation, __, and __.

Answer 47

elongation, termination

Question 48

In E. coli, what protein recognizes the base sequence of the promoter and causes RNA polymerase to bind to the promoter?

Answer 48

Sigma factor

Question 49

During which stage of transcription does RNA polymerase bind to the promoter?

Answer 49

Initiation

Question 50

RNA polymerase synthesizes the RNA transcript during the __ stage of transcription.

Answer 50

elongation

Question 51

In the coding strand, the __ in the DNA is replaced with __ in the mRNA.

Answer 51

thymine, uracil

Question 52

The strand of DNA that is used by RNA polymerase during transcription is called the __ strand.

Answer 52

template

Question 53

During the elongation stage of transcription, nucleotides bind to the template strand and are covalently connected in which direction?

Answer 53

5' to 3'

Question 54

During the initiation stage of bacterial transcription, the gene region called the __ functions as a recognition site for the sigma factor of RNA polymerase.

Answer 54

promotor

Question 55

The sequence of a DNA template is 3'-GGTTCCTT-5'. What is the sequence of the RNA molecule that will be transcribed from this template strand?

Answer 55

5'-CCAAGGAA-3'

Question 56

Which of the following events occur during the initiation stage of transcription? - The RNA transcript dissociates from the DNA. - Sigma factor is released. - RNA polymerase binds to the promoter. - DNA near the promoter is unwound to form an open complex.

Answer 56

RNA polymerase binds to the promoter. DNA near the promoter is unwound to form an open complex.

Question 57

During the termination stage of transcription, what happens when the RNA polymerase and the RNA transcript reach the terminator?

Answer 57

RNA polymerase dissociates from the DNA

Question 58

In a double-stranded DNA molecule, what DNA strand has almost the exact same sequence of bases as the mRNA that is synthesized from that molecule? Note that the only exception in sequence is that thymine in that DNA strand is replaced with uracil in the RNA.

Answer 58

The coding strand

Question 59

What RNA produced in eukaryotic transcription is the longest?

Answer 59

pre-mRNA

Question 60

Before leaving the nucleus, pre-mRNA transcripts are modified by splicing, as well as the addition of __ and __ to the ends of the mRNA.

Answer 60

caps, tails

Question 61

During transcription, ribonucleotides are added to the

Answer 61

3' end of the mRNA transcript

Question 62

What sequence of RNA will be transcribed from a DNA template strand that is 5'-ACGTAAC-3'?

Answer 62

3'-UGCAUUG-5'

Question 63

When RNA polymerase reaches a site called the __ region, it dissociates from the DNA at the end of transcription.

Answer 63

terminator

Question 64

Pre-mRNA molecules contain intervening sequences that are not translated. The intervening sequences are also known as:

Answer 64

introns

Question 65

In eukaryotes, transcription initially produces a longer RNA molecule called the __-__. This longer mRNA molecule is spliced, capped, and polyadenylated prior to translation.

Answer 65

pre mRNA

Question 66

How are eukaryotic mRNAs modified before leaving the nucleus?

Answer 66

Introns are removed by splicing. A cap is added to the 5' end. A poly(A) tail is added to the 3' end.

Question 67

During the elongation stage of transcription, nucleotides bind to the template strand and are covalently connected in which direction?

Answer 67

5' to 3'

Question 68

The sequence of a DNA template is 3'-GGTTCCTT-5'. What is the sequence of the RNA molecule that will be transcribed from this template strand?

Answer 68

5'-CCAAGGAA-3'

Question 69

The sequences that are removed from mRNA and not translated are called

Answer 69

introns

Question 70

In eukaryotic mRNA, sequences found in the mature mRNA are termed __.

Answer 70

exons

Question 71

What happens during the process of mRNA splicing?

Answer 71

Exons are joined together. Introns are removed from the transcript.

Question 72

During transcription, ribonucleotides are added to the

Answer 72

3' end of the mRNA transcript

Question 73

Which end of a eukaryotic mRNA is processed by the addition of a modified guanine cap?

Answer 73

5'

Question 74

Mature mRNAs of eukaryotes have a modified form of guanine covalently attached at the 5' end. This event is known as

Answer 74

capping

Question 75

What is the role of the 5' cap on a eukaryotic mRNA molecule?

Answer 75

It allows the mRNA to bind to a ribosome for translation. It facilitates the exit of mRNA from the nucleus.

Question 76

At the molecular level, coding sequences that are translated are found in:

Answer 76

exons

Question 77

How is the 3' end of a eukaryotic mRNA modified?

Answer 77

A poly A tail is added to it.

Question 78

How is the 5' end of a eukaryotic mRNA modified

Answer 78

A cap is added to it.

Question 79

What are the functions of the poly A tail on a mature eukaryotic mRNA?

Answer 79

It stabilizes the mRNA. It aids in the export of mRNA from the nucleus.

Question 80

Due to __, mature mRNAs of eukaryotes have a modified guanosine covalently attached at the 5' end.

Answer 80

capping

Question 81

The average human gene has about __ introns.

Answer 81

9

Question 82

In eukaryotic mRNAs, the 5' cap functions in all of the following EXCEPT

Answer 82

removal of introns from the mRNA

Question 83

In eukaryotic mRNA, sequences found in the mature mRNA are termed

Answer 83

exons

Question 84

A poly A tail is added to the ______ end of eukaryotic mRNAs.

Answer 84

3'

Question 85

What is the name of the complex that removes introns from eukaryotic pre-mRNA molecules?

Answer 85

Spliceosome

Question 86

A long poly A tail aids in the export of mRNAs from the:

Answer 86

nucleus

Question 87

What is true of introns?

Answer 87

Introns are found in many eukaryotic genes. A gene may have multiple introns.

Question 88

What is the role of the 5' cap on a eukaryotic mRNA molecule?

Answer 88

It facilitates the exit of mRNA from the nucleus. It allows the mRNA to bind to a ribosome for translation.