Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbiology > Chapter 11 Study Guide > Flashcards

Chapter 11 Study Guide Flashcards

(84 cards)

Start Studying
1
Q

Mutagens are often called _________, agents that cause cancer

A

Carcinogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

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

A

Codon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The mRNA is read in groups of 3 nucleotides

A

Codons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The codon _____ acts as a start codon

A

AUG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

There are 3 stop codons

A

UAA

UAG

UGA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Involves the exchange of DNA from one cell to another

A

Conjugation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

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

A

DNA polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

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

A

Genotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Expressed genes observable characteristics of an individual based on genotype

A

Phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

DNA ➡️ RNA ➡️ protein ➡️ gives function

A

Central dogma of genetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

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

A

Helicase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

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

A

Ligase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

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

A

Okazaki fragments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

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

A

Operators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

A _______ allows close contact between cells

A bridge forms between the cell

A

Pilus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

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

A

RNA polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Refers to the twisting and coiling of DNA

A

Supercoiled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
In ______, bacteria receive DNA via a bacteriophage
Transduction
26
In _______, naked DNA in the enviorment is taken up by the cell
Transformation
27
The DNA may be incorporated into the chromosome or remain as a plasmid in the cytoplasm
Transformation
28
During ______, a polypeptide chain is made using mRNA as a template
Translation
29
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
Transposons
30
Are segments of DNA that have the ability to move from one location to another because they code for the enzyme transposase
Transposons
31
What are the two essential functions of DNA ?
Replicate itself for cellular reproduction Instruct the cell how to make the proteins it needs
32
The process of producing a protein through transcription and translation is called
Gene expression
33
Are all genes in a cell expressed at all times ?
No, cells can selectively express genes based on their needs, developmental stage, or environmental conditions
34
Genes that are always expressed are known as _______; known as housekeeping genes because they are necessary for the basic functions of the cell
Constitutive genes
35
Regulates genes ______ as needed
Turned on and off
36
Why is DNA replication described as semi conservative ?
Because each new DNA molecule formed consists of one original strand and one newly synthesized strand.
37
the location in the chromosome where DNA replication begins
Origin of replication
38
1 origin of replication, circular DNA Multiple origins of replication, linear DNA
Prokaryote Eukaryotes
39
Why are Topoismerases needed for replication ?
They prevent supercoiling
40
In what direction does replication occur ?
5’ ➡️ 3’
41
synthesized continuously in the same direction as the replication fork synthesized discontinuously in fragments, moving opposite to the forks direction
Leading strand Lagging strand
42
Synthesizes RNA primers needed to start replication
Primase
43
Short DNA fragments formed on the lagging strand
Okazaki fragments
44
What enzyme joins Okazaki fragments together
Ligase
45
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
Proofreading
46
Introduces single stranded break into concatenated chromosomes to release them from each other, and then reseals the DNA
Topoismerase IV
47
Since the bacterial chromosomes are circular, a special enzyme is needed to separate the two daughter cells
Topoismerase IV
48
Is to copy a genes DNA sequence into RNA
Transcription
49
The _______ is a DNA sequence that serves as the binding site for RNA
promoter
50
Is found upstream before the gene near the 5’ end of the coding strand
Promoter location
51
Which enzyme is the key enzyme needed to produce mRNA
RNA polymerase
52
same sequence as RNA but with the T instead of U Read by rna polymerase to make complementary rna
Coding strand Template strand
53
During transcription which nucleotide pairs with adenine ?
Uracil
54
How does RNA polymerase “know” when it has reached the end of a gene?
Recognizes termination signals
55
What is the purpose of translation ?
Synthesize proteins from the mRNA template
56
What two types of RNA are needed for translation, in addition to mRNA
tRNA rRNA
57
A ______ is a sequence of three nucleotides in mRNA that corresponds to a specific amino acid
Codon
58
There are 61 _______ that specify amino acids
Sense codons
59
There are 3 ________ that signal the termination of protein synthesis
Nonsense codons
60
Nonsense codons
UAA UAG UGA
61
There is 1 ________, which not only indicates the start of translation
Start codon AUG
62
All cells use the same decoder ring
Universal
63
Nucleotides are read in groups of 3
Triplet
64
Each nucleotide is only used once. Codons nerve overlap each other
Nonoverlapping
65
In ______, transcription and translation can occur at the same time. In ______, transcription and translation are completed separately
Prokaryotes Eukaryotes
66
Any inheritable change in the DNA is a
Mutation
67
Are caused by replication errors
Spontaneous mutations
68
Are caused by mutagens
Induced mutations
69
A _______ is any agent that causes changes in the DNA sequence of an organism
Mutagen
70
Mutagens are often called ________, agents that cause cancer
Carcinogens
71
A ______ is a change in a single nucleotide in the DNA sequence
Point mutation
72
An _______ is a mutation that involves the addition of one or more nucleotide bases into the DNA sequence
Insertion mutation
73
A ________ is a mutation that involves the removal of one or more nucleotide bases from the DNA sequence
Deletion
74
A _______ results in a different amino acid being incorporated into the resulting polypeptide
Missense mutation
75
A ________ converts a codon encoding an amino acid into a stop codon
Nonsense mutation
76
Caused by insertions or deletions of a number of nucleotides that are not multiple of three
Frameshift mutations
77
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
Silent mutation
78
Genetic diversity can be achieved through
Horizontal gene transfer
79
Do all cells have operon ?
No, just prokaryotes
80
The ______ is a DNA sequence where regulatory proteins bind to control the transcription of the operon
Operator
81
Where is the operator found ?
It is located between the promoter and the structural genes of the operon
82
preventing transcription of the lac operon when lactose is absent
Repressor
83
In the absence of lactose, the lac repressor binds the operator, and transcription is
Blocked
84
In the presence of lactose, the lac repressor is released from the operator, and transcription proceeds at a
Slow rate

Microbiology (30 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions