Chapter 11 Study Guide Flashcards

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1
Q

Mutagens are often called _________, agents that cause cancer

A

Carcinogens

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2
Q

Each amino acid is defined within the mRNA by a triplet of nucleotides called a

A

Codon

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3
Q

The mRNA is read in groups of 3 nucleotides

A

Codons

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4
Q

The codon _____ acts as a start codon

A

AUG

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5
Q

There are 3 stop codons

A

UAA

UAG

UGA

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6
Q

Whereas 61 of the 64 possible triplets code for amino acids, three of the 64 codons do not code for an amino acid; they terminate protein synthesis, releasing the polypeptide from the translation machinery. These are called the _________ ?

A

Stop codons or nonsense codons

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7
Q

Involves the exchange of DNA from one cell to another

A

Conjugation

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8
Q

Is an essential enzyme responsible for synthesizing new DNA strands during the process of DNA replication

A

DNA polymerase

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9
Q

Types of genes an individual carries (genetic makeup of an individual)

A

Genotype

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10
Q

Expressed genes observable characteristics of an individual based on genotype

A

Phenotype

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11
Q

DNA ➡️ RNA ➡️ protein ➡️ gives function

A

Central dogma of genetics

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12
Q

An enzyme called _____, then separates the DNA strands by breaking the hydrogen bonds between nitrogenous bases

A

Helicase

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13
Q

One strand is made in segments called Okazaki fragments (lagging strand) and are joined together with a

A

Ligase

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14
Q

Any inheritable change in the DNA is a mutation

Spontaneous mutations are caused by _______

Induced mutations are caused by ______

A

Replication errors

Mutagens

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15
Q

Are short segments of DNA formed on the lagging strand during DNA replication

A

Okazaki fragments

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16
Q

An _______ is a segment of DNA to which a repressor protein binds to regulate the expression of a set of genes, often part of the operon.

A

Operators

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17
Q

Are key elements in the regulation of gene transcription, controlling whether certain genes are turned on or off.

A

Operators

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18
Q

In bacteria and archea, structural proteins with related functions are usually encoded together within the genome in a block called an _____ and are transcribed together under the control of a single promoter, resulting in the formation of a polycistronic transcript

A

Operon

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19
Q

A _______ allows close contact between cells

A bridge forms between the cell

A

Pilus

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20
Q

A _____ is a specific region of DNA that acts as a starting point for gene transcription.

It’s where RNA polymerase binds to begin copying the genetic instructions into mRNA

A

Promoter

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21
Q

Is the process by which a cell copies its DNA to pass genetic information to the next generation of cells during cell division.

A

DNA replication

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22
Q

Is an enzyme that synthesizes RNA from a DNA template during the process of transcription

A

RNA polymerase

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23
Q

Refers to the twisting and coiling of DNA

A

Supercoiled

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24
Q

Is an enzyme that regulates the overwinding or under winding of DNA during the processes such as replication, transcription, and chromosome condensation.

A

Topoismerase

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25
Q

In ______, bacteria receive DNA via a bacteriophage

A

Transduction

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26
Q

In _______, naked DNA in the enviorment is taken up by the cell

A

Transformation

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27
Q

The DNA may be incorporated into the chromosome or remain as a plasmid in the cytoplasm

A

Transformation

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28
Q

During ______, a polypeptide chain is made using mRNA as a template

A

Translation

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29
Q

Also called “jumping genes”

Found in both prokaryotes and eukaryotes

May slo carry genes, such as for antibiotics resistance

Can insert themselves randomly into a chromosome

A

Transposons

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30
Q

Are segments of DNA that have the ability to move from one location to another because they code for the enzyme transposase

A

Transposons

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31
Q

What are the two essential functions of DNA ?

A

Replicate itself for cellular reproduction

Instruct the cell how to make the proteins it needs

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32
Q

The process of producing a protein through transcription and translation is called

A

Gene expression

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33
Q

Are all genes in a cell expressed at all times ?

A

No, cells can selectively express genes based on their needs, developmental stage, or environmental conditions

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34
Q

Genes that are always expressed are known as _______; known as housekeeping genes because they are necessary for the basic functions of the cell

A

Constitutive genes

35
Q

Regulates genes ______ as needed

A

Turned on and off

36
Q

Why is DNA replication described as semi conservative ?

A

Because each new DNA molecule formed consists of one original strand and one newly synthesized strand.

37
Q

the location in the chromosome where DNA replication begins

A

Origin of replication

38
Q

1 origin of replication, circular DNA

Multiple origins of replication, linear DNA

A

Prokaryote

Eukaryotes

39
Q

Why are Topoismerases needed for replication ?

A

They prevent supercoiling

40
Q

In what direction does replication occur ?

A

5’ ➡️ 3’

41
Q

synthesized continuously in the same direction as the replication fork

synthesized discontinuously in fragments, moving opposite to the forks direction

A

Leading strand

Lagging strand

42
Q

Synthesizes RNA primers needed to start replication

A

Primase

43
Q

Short DNA fragments formed on the lagging strand

A

Okazaki fragments

44
Q

What enzyme joins Okazaki fragments together

A

Ligase

45
Q

In _______, the DNA polymerase reads the newly added base, ensuring that it is complementary to the corresponding base in the template strand before adding the next one

A

Proofreading

46
Q

Introduces single stranded break into concatenated chromosomes to release them from each other, and then reseals the DNA

A

Topoismerase IV

47
Q

Since the bacterial chromosomes are circular, a special enzyme is needed to separate the two daughter cells

A

Topoismerase IV

48
Q

Is to copy a genes DNA sequence into RNA

A

Transcription

49
Q

The _______ is a DNA sequence that serves as the binding site for RNA

A

promoter

50
Q

Is found upstream before the gene near the 5’ end of the coding strand

A

Promoter location

51
Q

Which enzyme is the key enzyme needed to produce mRNA

A

RNA polymerase

52
Q

same sequence as RNA but with the T instead of U

Read by rna polymerase to make complementary rna

A

Coding strand

Template strand

53
Q

During transcription which nucleotide pairs with adenine ?

A

Uracil

54
Q

How does RNA polymerase “know” when it has reached the end of a gene?

A

Recognizes termination signals

55
Q

What is the purpose of translation ?

A

Synthesize proteins from the mRNA template

56
Q

What two types of RNA are needed for translation, in addition to mRNA

A

tRNA

rRNA

57
Q

A ______ is a sequence of three nucleotides in mRNA that corresponds to a specific amino acid

A

Codon

58
Q

There are 61 _______ that specify amino acids

A

Sense codons

59
Q

There are 3 ________ that signal the termination of protein synthesis

A

Nonsense codons

60
Q

Nonsense codons

A

UAA
UAG
UGA

61
Q

There is 1 ________, which not only indicates the start of translation

A

Start codon AUG

62
Q

All cells use the same decoder ring

A

Universal

63
Q

Nucleotides are read in groups of 3

A

Triplet

64
Q

Each nucleotide is only used once. Codons nerve overlap each other

A

Nonoverlapping

65
Q

In ______, transcription and translation can occur at the same time.

In ______, transcription and translation are completed separately

A

Prokaryotes

Eukaryotes

66
Q

Any inheritable change in the DNA is a

A

Mutation

67
Q

Are caused by replication errors

A

Spontaneous mutations

68
Q

Are caused by mutagens

A

Induced mutations

69
Q

A _______ is any agent that causes changes in the DNA sequence of an organism

A

Mutagen

70
Q

Mutagens are often called ________, agents that cause cancer

A

Carcinogens

71
Q

A ______ is a change in a single nucleotide in the DNA sequence

A

Point mutation

72
Q

An _______ is a mutation that involves the addition of one or more nucleotide bases into the DNA sequence

A

Insertion mutation

73
Q

A ________ is a mutation that involves the removal of one or more nucleotide bases from the DNA sequence

A

Deletion

74
Q

A _______ results in a different amino acid being incorporated into the resulting polypeptide

A

Missense mutation

75
Q

A ________ converts a codon encoding an amino acid into a stop codon

A

Nonsense mutation

76
Q

Caused by insertions or deletions of a number of nucleotides that are not multiple of three

A

Frameshift mutations

77
Q

A point mutation will commonly result in the same amino acid being incorporated into the resulting polypeptide despite the sequence change. This change will have no effect on the proteins structure and is thus called a

A

Silent mutation

78
Q

Genetic diversity can be achieved through

A

Horizontal gene transfer

79
Q

Do all cells have operon ?

A

No, just prokaryotes

80
Q

The ______ is a DNA sequence where regulatory proteins bind to control the transcription of the operon

A

Operator

81
Q

Where is the operator found ?

A

It is located between the promoter and the structural genes of the operon

82
Q

preventing transcription of the lac operon when lactose is absent

A

Repressor

83
Q

In the absence of lactose, the lac repressor binds the operator, and transcription is

A

Blocked

84
Q

In the presence of lactose, the lac repressor is released from the operator, and transcription proceeds at a

A

Slow rate