Chapter 9 Flashcards
1
Q
The science of heredity is also known as ______.
A
Genetics
2
Q
Which term represents all of the genetic information within a cell?
A
Genome
3
Q
Eukaryotic chromosomes are composed of ______.
A
DNA
4
Q
The DNA of a chromosome is ______-stranded.
A
Double
5
Q
Which of the following are parts of a nucleotide in DNA?
A
Deoxyribose sugar
Phosphate
Nitrogenous base
6
Q
The study of the inheritance in living things is ______.
A
Genetics
7
Q
Which component of DNA determines the 3’ and 5’ ends of the strands?
A
Carbons in the deoxyribose sugar
7
Q
The building blocks of DNA structure are ______.
A
Nucleotides
8
Q
The complete set of chromosomes and genes in an organism is referred to as the ______.
A
Genome
9
Q
A discrete cellular structure composed of a neatly packaged DNA molecule is a(n) ______.
A
Chromosome
10
Q
In DNA, a purine always combines with ______.
A
A pyrimidine
11
Q
A DNA nucleotide is composed of a(n) ______, a(n) ______ sugar, and a(n) ______ base.
A
Phosphate; deoxyribose; nitrogenous
12
Q
The basic unit of DNA structure is a(n):
A
Nucleotide
13
Q
The purine nitrogenous bases found in DNA are guanine and ______.
A
Adenine
14
Q
What is a true statement about the replication of cells and viruses?
A
The general process of replication is similar in cells and viruses.
14
Q
A nucleotide is oriented 5’ or 3’ depending on the location of the ______ on the strand of DNA.
A
Deoxyribose carbons
15
Q
Adenine pairs with ______ in DNA, whereas cytosine pairs with ______.
A
Thymine; guanine
16
Q
DNA polymerase ______ is the main enzyme involved in the building of the new DNA chain, whereas DNA polymerase ______ is involved mostly with removing the primers and repairing damaged DNA.
A
III; I
17
Q
The newly made double helices are composed of one parent template and one newly synthesized strand as a result of ______ replication.
A
Semiconservative
18
Q
The place where DNA replication is initiated is called the ______.
A
Origin of replication
19
Q
DNA polymerase ______ is the main enzyme responsible for building the DNA strand during DNA replication.
A
III
20
Q
True or false: The process of replication is fundamentally different in prokaryotic cells, eukaryotic cells, and viruses.
A
False
21
Q
The enzyme involved in replicating a new DNA strand is DNA polymerase ______, while DNA polymerase ______ is involved in removing the RNA primer, closing gaps, and repairing mismatched bases.
A
III; I
22
Q
All new DNA strands are synthesized from:
A
5’ to 3’
23
Which is true regarding semiconservative DNA replication?
Each new DNA helix contains one parent strand and one newly synthesized strand.
24
The point on a replicating DNA molecule where the DNA polymerase synthesizes new strands of DNA is the replication ______.
Fork
25
DNA polymerase III is responsible for:
Building the DNA chain.
26
Which strand is replicated continuously, without segments, during DNA replication?
Leading
27
Which strand is replicated discontinuously in segments during DNA replication?
The lagging strand only
28
Nucleotides can only be added to a growing DNA chain in the ______ direction.
5' to 3'
29
Fragments that are formed during DNA replication of the lagging strand are called ______ fragments.
Okazaki
30
The newly made double helices are composed of one parent template and one newly synthesized strand as a result of ______ replication.
Semiconservative
31
In E. coli, DNA polymerase I removes the ______ primers and replaces them with ______.
RNA; DNA
32
How many replication forks are formed when opening a section of a circular DNA molecule during replication of the bacterial chromosome?
2
33
Which best describes the flow of genetic information in a cell?
DNA encodes RNA which encodes protein
34
The term ______, or codon, is a sequence of 3 nucleotides in DNA that encodes an amino acid.
Triplet
35
How does RNA differ from DNA?
In RNA, uracil replaces thymine.
RNA is single-stranded.
36
The three types of RNA that are directly involved in making protein are ______ RNA, ______ RNA, and ______ RNA.
Messenger; transfer; ribosomal
37
DNA polymerase I works to ______ RNA primers from newly-synthesized DNA.
Remove
38
The flow of genetic information in a cell is a process starting with ______ which encodes ______ which encodes protein.
DNA; RNA (m)
39
In RNA, which nitrogenous base pairs with adenine?
Uracil
40
Which pentose sugar is found in DNA?
Deoxyribose
41
Unlike DNA, RNA contains the nitrogenous base ______.
Uracil
42
Which of the following types of RNA is the transcribed version of a structural gene in DNA, that is later read for translation into protein?
mRNA
42
Which pentose sugar is found in RNA?
Ribose
43
Which type of RNA comprises ribosomal subunits?
rRNA
44
Which of the following types of RNA delivers the amino acids to the growing peptide chain in translation?
tRNA
45
Which of the following are functions of RNA polymerase?
Unwinds the DNA so that transcription can take place
Synthesizes an RNA molecule from DNA template
46
The RNA form that contains the transcribed code for a protein from the original DNA strand is ______ RNA.
Messenger
47
To initiate transcription, RNA polymerase binds to the ______ region of DNA.
Promoter
48
Which is the correct order of events in transcription?
Initiation, elongation, termination
49
The RNA type that transfers amino acids to the growing peptide chain in translation is ______ RNA.
Transfer
50
RNA polymerase is guided to the correct position on the promotor by the ______ factor.
Sigma
51
Two subunits of the ______ come together to perform protein synthesis.
Ribosome
52
The main enzyme responsible for transcription is:
RNA polymerase
52
The subunit of the ribosome that holds tRNAs and catalyzes peptide bond formation by means of a ribozyme is the ______ subunit.
Large
53
In translation, mRNA is guided by the ______ and ______ sites on the large ribosomal subunit.
P; A
54
RNA polymerase binds to which region of DNA to begin transcription?
Promoter
54
The ______ of a tRNA is complementary to a(n) ______ of mRNA.
Anticodon; codon
55
The sigma factor of bacterial RNA polymerase enables the enzyme to ______.
Recognize the promoter
56
True or false: Several codons can code for the same amino acid, which is called the redundancy of the code.
True
57
The mRNA sequence AUG, specifying the first amino acid in protein sequences, is called the ______ codon.
Start
58
During translation initiation, the ______ ribosomal subunit binds to a specific site on the mRNA to start translation.
Small
59
Events of translation
1. The mRNA attaches to the ribosome.
2. Two tRNA molecules bring amino acids to the ribosome
3. A peptide bond forms between the amino acids
4. The first tRNA exits at the E site
5. The second tRNA shifts to the P site while the third tRNA enters the A site
6. The process repeats with additional tRNA molecules
7. A stop codon is encountered
60
tRNA, that has released the amino acid it carried, leaves the ribosome through the ______ site.
E
61
Some amino acids can be encoded by several different codons. For that reason, we say that the genetic code is ______.
Redundant/degenerate
62
DNA sequences found within a gene that do not encode the protein corresponding to the gene are ______.
Intron
62
If a codon of mRNA reads 5'-UUG-3', the tRNA that delivers the amino acid to this location during translation will have an anticodon of 3'-______-5'.
AAC
63
Which occur during posttranslational modification?
Proteins join with other proteins to form quaternary structures.
Cofactors are added to proteins destined to become enzymes.
Formyl-methionine is removed from the start of the polypeptide chain.
64
The AUG codon of mRNA is associated with the amino acid methionine, but is also an indication to ______ translation.
Start
65
Translation termination occurs when ______.
One of three stop codons is reached by the ribosome
66
Which are components of an operon in a sequence of DNA?
Regulatory region
Structural genes
66
Alterations to a protein made after translation, such as removal of f-met, addition of cofactors, and joining with other proteins for quaternary structure, are referred to as ______ modifications.
Posttranslational
67
Which DNA sequences are found within a gene but do not encode the protein specified by that gene?
Introns
68
Two components of an operon include the ______ region and the ______ gene sequences.
Regulatory; structural
69
The feature of the lac operon that is capable of stopping the activity of the operon is a(n) ______.
Regulator/repressor
69
Which kind of lac operon gene encodes an enzyme that is needed to catabolize lactose?
Structural
70
What binds to an inactive repressor to make an active repressor?
Corepressor
71
What is a riboswitch?
A region within an mRNA that regulates the translation of the mRNA of which they are a part
72
An alteration in the DNA sequence of a cell is a(n) ______.
Mutation
73
Mutations in DNA that are caused by random mistakes in replication, and are not known to be the result of any mutagenic agent, are ______ mutations.
Spontaneous
74
The genes of an operon that code for proteins are ______ genes.
Structural
74
The protein which is capable of stopping the output of product encoded by the lac operon is called a(n) ______.
Repressor
75
One DNA repair mechanism that removes incorrect bases, and replaces them with correct ones, is the ______ repair mechanism.
Excision
75
An inactive repressor binds to a(n) ______ to make an active repressor.
Corepressor
76
The addition, deletion, or substitution of no more than a few bases as the result of a mutation is referred to as a(n) ______ mutation.
Point
77
In what way can a riboswitch directly regulate translation?
By changing the shape of the mRNA
78
True or false: A mutation is an alteration in the DNA sequence or content of a cell that is passed on when the cell divides.
True
79
What is the purpose of the Ames test?
To determine the carcinogenic potential of a chemical
80
Which type of mutation is due to random mistakes in replication?
Spontaneous mutation
81
True or false: Mutations are always harmful to cells.
False
82
Mutations that involve the addition, deletion, or substitution of one or a few bases are referred to as ______ mutations.
Point
83
Which process uses visible light to repair DNA that has been damaged by ultraviolet radiation?
Photoactivation
84
When one bacterium donates DNA to other bacterium, it is known as ______.
Recombination
85
What is a small circular segment of DNA found in the cytoplasm of prokaryotes that is capable of independent replication and usually contains nonessential genes?
Plasmid
86
The carcinogenic potential of a chemical can be determined by the ______ test.
Ames
87
Which form of genetic recombination involves DNA transfer that is mediated through the action of bacterial viruses?
Transduction
88
What is the name of the specialized plasmid that directs conjugation in gram-negative cells?
F factor
89
A sex pilus functions in most transfers of genes between bacteria that are known ______ transfers.
Conjugation
89
A small number of ______ are considered beneficial in that they provide the cell with a useful change in structure or physiology.
Mutations
90
A donor cell with a F (fertility) ______ is considered F+
in bacterial conjugation.
Factor/plasmid
90
Which term refers to the transfer of genes from donor to recipient microorganisms?
Recombination
90
In bacterial conjugation, which term refers to a recipient cell that does not have a fertility plasmid?
F-
91
Donor and recipient bacterial cells are connected by the sex ______ during conjugation.
Pilus
91
When the F factor is transferred by E. coli, ______.
No additional donor genes are transferred
91
A recipient cell having no F (fertility) ______ DNA is considered F- in bacterial conjugation.
Factor/plasmid
91
During which method of gene transfer are bacterial cells in direct contact?
Conjugation
92
In bacterial conjugation, which term refers to a donor cell with a fertility plasmid?
F+
93
Which type of donor has the fertility factor integrated into the chromosome in bacterial conjugation?
Hfr
94
True or false: A donor cell typically copies the F factor before transferring it to another cell.
True
95
True or false: R-factors or "resistance factors" can be shared between bacteria through conjugation to help them survive the effects of antibiotics.
True
96
Which gene transfer method involves the uptake of free DNA by competent bacterial cells?
Transformation
97
During the process of ______ a competent bacterial cell may accept soluble DNA from the surrounding environment.
Transformation
97
A sex pilus functions in most transfers of genes between bacteria that are known as ______ transfers.
Conjugation
98
Which recombination method involves transfer of DNA via bacteriophages?
Transduction
99
True or false: In bacterial conjugation, all F+ donor cells are high frequency recombinant (Hfr) cells.
False
100
Which type of plasmids confer the ability of an organism to survive treatment by antibiotics?
R factors
101
Random portions of host DNA are transferred by bacteriophage during ______ transduction.
Generalized
102
A bacterial cell described as ______ can accept soluble DNA from the surrounding environment.
Competent
103
Genes that are able to shift from one part of the genome to another are ______.
Transposons
104
Which of the following is the genetic pattern of viral genomes?
Single or double stranded DNA or RNA
105
Due to the separation of prophage DNA from the bacterial chromosome, a specific, adjacent part of the host genome is transferred during ______ transduction.
Specialized
106
Viral initiators of cancer are termed ______.
Oncogenic
107
RNA viruses with a ______-strand genome must be converted to a ______-strand genome before translation.
Negative; positive
108
"Jumping genes" are known as ______.
Transposons
109
True or false: Viral genomes are always composed of either single or double stranded DNA.
False
110
