EXAM 3. Chapter 7,8,9
The ______________ DNA strand is used as template for RNA synthesis.
Minus ( - )
Errors by DNA polymerase that incorporate the wrong nucleotide into replicating DNA can be repaired quickly by which two mechanisms?
Mismatch repair Proofreading by DNA polymerase
The function of mRNA is to
Serve as a template for protein synthesis
Microorganisms must adapt rapidly to changes in their environment in order to
Survive
An mRNA sequence has ______________.
THREE potential reading frames, but ONLY ONE is typically used for TRANSLATION.
Which of the following is found in all DNA nucleotides?
The same sugar & phosphate, but different nucleobases.
made of double stranded RNA
neither plasmids nor chromosomes
Restriction-modification systems were discovered
while studying why certain bacterial strains are relatively resistant to phage infection
Alternative sigma factors allow cells to directly control _________.
transcription
When an excision errors produces a plasmid containing both chromosomal and F plasmid DNA, the resulting plasmid is called a(n) plasmid.
F' or F prime
The _______ is the nucleotide sequence in the DNA of a cell or an organism.
Genotype
In ___________ gene transfer, DNA moves from one organism to another
Horizontal
Protection against the toxic effects of antimicrobial compounds or heavy metals is often encoded on plasmids called _________ plasmids
R or Resistance
Transcription enzyme called
RNA Polymerase
The consequences of not repairing damaged DNA in cells include ______.
cancer (in animals) cell death
Chemicals that cause cancer are known as ______, and most of them are _______
carcinogens; mutagens
found in all eukaryotes and prokaryotes
chromosomes only
Type of DNA damage repair illustrated here
Base excision repair
A bacteriophage consists of a genome made up of DNA or ______ , surrounded by a coat made up of _________
Blank 1: RNA Blank 2: protein, polypeptides, or proteins
A _____________ is composed of any genes.
Chromosome
Which of the following plasmids encodes all the necessary genetic information for transfer from one bacterial cell to another?
Conjugative plasmids only
Enzymes involved in essential metabolic pathways such as glycolysis are usually
Constitutive
In the recent years, new field of bioinformatics has emerged, which _____
Created the computer technology to store, retrieve, and analyze nucleotide sequence data
Repair of nucleotide incorporation errors during the process of DNA replication is accomplished by __________ by DNA polymerase and by _______.
Blank 1: proofreading Blank 2: mismatch
The function of tRNA is to __________.
Carry the amino acids used in translation.
In bacteria,____________ refers to DNA transfer requiring cell to cell contact.
Conjugation
A plasmid that can directs its own transfer from donor to recipient cells is called a(n) ________
Conjugative
The ____ correlates a series of three nucleotides to one amino acid or a stop codon.
Genetic Code
Information encoded in genetic material is translated into proteins based on rules known as the
Genetic code
The ____________ is the complete set of chromosomes & genes in an organism.
Genome
________ mutations are genetic changes caused by factors from outside of the cell such as radiation or chemicals.
Induced
This figure highlights the ________ phase of translation in bacteria.
Initiation
Eukaryotic cells can regulate the levels of mRNA by destroying specific RNA transcripts through a process known as RNA ____________________ abbreviated RNAi.
Interference
What is the function of RNAi ?
Interference with translation by targeting a specific mRNA.
Why is the genetic code said to be redundant?
More than one codon can code for a specific amino acid.
Which term refers to an organism that has a mutation?
Mutant
What are the THREE major structures directly involved in TRANSLATION?
Ribosomes, mRNA, tRNA.
Process of decoding information carried by mRNA to synthesize a protein.
Translation
Mutagens that are DNA segments that can insert into genes and thereby inactivate them are called ______.
Transposons
_________ are segments of DNA that can move from one location to another in a cell's genome.
Transposons
_______________ are DNA segments that increase the rate of mutations by inserting themselves into genes and inactivating them.
Transposons
Sequence of 3 DNA nucleotides that codes for one amino acid is called?
Triplet
In ____________ gene transfer, DNA is passed from a parent cell to its progeny.
Vertical
Which of the following types of radiation are mutagenic?
X-rays Ultraviolet rays
A replication fork is a
a Y-shaped structure where both DNA strands are being replicated.
for the lac operon in E. coli, under conditions in which glucose is absent and lactose is present which of the following is true?
Cells preferentially use glucose and only use lactose if the glucose is depleted
A(n) ______________________ is the specific sequence of THREE nucleotides in mRNA that encode a particular amino acid or a stop signal.
Codon
Which of the following can be found in a bacteriophage?
DNA or RNA genome protein coat
After the initiation of replication of a bacterial chromosome, the enzyme _______________ adds nucleotides to a growing strand.
DNA polymerase.
As part of DNA replication, Okazaki fragments are made during the synthesis of the ______.
Lagging strand in DISCONTINUOUS manner.
In DNA replication, the synthesis of one new strand proceeds continuously as fresh template is exposed
Leading
The amino acid that is placed first during translation in bacteria is _______________.
N - formylmethionine
A _________ composed of amino acids.
Protein
What enzyme binds to a DNA promoter region to initiate transcription?
RNA polymerase
__________ is used during transcription of DNA to RNA.
RNA polymerase
Protein synthesis involves ______________, which align amino acids & catalyze peptide bond formation between them.
Ribosomes or RNA
THREE MAJOR STRUCTURES
Ribosomes, tRNA , mRNA
Extensively damaged DNA activates the __________ repair mechanism, which cannot always determine the correct nucleotide sequence, thus introducing mutations resulting from the repair process itself.
SOS
TRUE OR FALSE : Several codons code for the SAME amino acid, which is called the Redundancy of the code. Because of Redundancy, the genetic codes is said to be degenerate.
TRUE, Redundancy of genetic code results in several codons encoding the same amino acid.
TRUE or FALSE : Regulating gene expression involves controlling mRNA synthesis and rapidly destroying mRNA transcripts.
TRUE. Rapidly destroyed in cell, mRNA synthesis is regulated by turning genes "on" & "off".
How many template strands exist in a replication fork?
TWO ( 2 )
The single - stranded DNA from which a new DNA strand is synthesized is referred to as the ___________.
Template
The signal to end protein synthesis is indicated by sequences called
Termination Codons
Which of the following are caused by chemical mutagens?
base substitutions frameshift mutations
An origin of transfer is encoded by
both conjugative and mobilizable plasmids
An origin of transfer is encoded by _______.
both conjugative and mobilizable plasmids
contains an origin of replication
both plasmids and chromosomes
TRUE or FALSE : An RNA transcript is a strand of RNA copied from an RNA template.
FALSE.
The process by which organisms best adapted to a given environment will predominate in that environment is called _______.
Natural selection
In humans, two of the genes associated with the development breast cancer encode enzymes involved in ______.
DNA repair
Selecting penicillin-resistant mutants by plating them on a medium containing penicillin is an example of ______ selection.
Direct
When an excision errors produces a plasmid containing both chromosomal and F plasmid DNA, the resulting plasmid is called a(n) _______ plasmid.
F' or F prime
The lac Oberon only functions when ___________ is present in the medium, but _______ is absent from the medium.
Lactose ; glucose
The DNA strand that is synthesized discontinuously during DNA replication, forming Okazaki fragments, is called the
Lagging Strand
Viral DNA that has been integrated into bacterial chromosome
Prophage
Transmission from outside of the cell to the inside of cell
Signal transduction
Segments of DNA that can move to new positions within the genome of a single cell are called
TRANSPOSONS
True or false: Incorporation of an incorrect nucleotide in a molecule of DNA results in a distortion of the DNA helix that can be detected by repair enzymes.
TRUE
A tRNA has a(n) ,_______ a group of three nucleotides that is complementary to the codon of the mRNA.
Anticodon
The genetic code includes _____ STOP Codons.
3
When integrated F plasmid DNA in an Hfr cell is excised from the chromosome, an excision error can result in the removal of chromosomal DNA along with the F plasmid DNA, creating a plasmid called
F' or F plasmid
True or false: Ultraviolet rays are chemical mutagens. True false question.
FALSE
A _____________ is a sequence of nucleotides that usually codes for one funcional protein.
Gene
What is the outcome IF Translation BEGINS at the wrong reading frame?
Generally, a non-functional protein is made.
Genetic change in bacteria occurs through which two mechanisms?
horizontal gene transfer mutation
_________ is transcribed from a DNA template & translated during protein synthesis.
mRNA or Messenger RNA
Sequence of DNA at which replication is initiated
origin of replication
typically do not encode genes essential to the life of the cell
plasmids only
A _____________ mutation occurs if a single base pair is changed during DNA synthesis.
point
All of the following are examples of means by which microorganisms can respond to changing environmental conditions EXCEPT.
production of different ribosomes
Which type of RNA molecule is included in the composition of ribosomal subunits?
rRNA
What is the proper order of the following events in the expression of a eukaryotic gene. 1.) Translation 2.) RNA processing 3.) Transcription
3 , 2 , 1 Transcription , RNA processing , and Translation
How many codons are used to specify the 20 possible amino acids?
61
The genetic code is comprised of 64 different codons. Out of these, ______ codes a specific amino acid.
61
Which of the following describes the termination of translation?
A STOP codon is reached & the polypeptide is released from ribosome.
An RNA transcript is strand of RNA copied from a _______ template.
DNA
The molecule that encodes all the instructions needed to produce a cell's component is ________.
DNA
During repair of oxidized guanine, which enzyme removes the damaged nucleobase from the sugar-phosphate backbone?
DNA glycosylase
An essential macromolecule that encodes all of the information needed by a cell to synthesize its components is _________.
DNA or Deoxyribonucleic acid
During replication, DNA polymerases ____________.
Add nucleotides to the 3' end of the new DNA strand.
Mutants that can grow under conditions in which the parent (wild type) cells cannot are easily isolated by ______________
Direct or Positive
An auxotroph can be isolated from a prototrophic parent strain by ______ selection.
Indirect
_____________ selection is used to isolate an auxotroph from a prototrophic parent strain, because no selective medium exists to inhibit the parent.
Indirect or Negative
All DNA nucleotides contains the same deoxyribose & phosphate group, but different________.
Nucleobases
Which type of DNA repair is shown in this figure?
Nucleotide excision repair
________ Strand of DNA contains the SAME ORDER of NUCLEOTIDES as the corresponding RNA transcript.
PLUS ( + )
Ability of Escherichia Colli to randomly turn on or off the production of attachment pills is an example of
Phase variation
Process that repairs thymine dimers by braking the covalent binds that have formed between adjacent thymines
Photoreactivation
When describing conjugation in Gram-negative bacteria, a donor cell with an F ______ is considered F+, while that without this structure are termed F-.
Plasmid
________ are circular pieces of bacterial DNA that do not usually encode information essential to the life of a cell.
Plasmids
What enzyme synthesizes the short segments of RNA required to initiate DNA replication]
Primase
In this image of a bacterial chromosome replicating, the openings the labels are pointing to are called the
Replication Forks
In bacteria, the ribosome starts to assemble at a sequence in mRNA called the ____________ - ___________ site. Translation begins at the first AUG codon after that.
Ribosome Binding
Information is passed from the environment into the cell by a process is known as signal
Transduction
Transfer of bacterial DNA from donor to recipient via bacteriophage
Transduction
The process of bacterial ______ involves the uptake of "naked" DNA by competent bacterial recipient cells.
Transformation
Uptake of naked DNA from
Transformation
Which mechanism of gene transfer involves the uptake of "naked" DNA by competent bacterial recipient cells?
Transformation
During what process is the information in mRNA used to make a protein?
Translation
Which of the following are possible outcomes of a base substitution?
nonsense mutation missense mutation synonymous mutation
Random genetic changes that result from normal cellular processes are ______.
spontaneous mutations
When bacteriophages replicate, phage components are synthesized in the host cell and assemble into new viruses ______.
within that cell before being released
Alter characteristics of certain surface proteins, allowing them to avoid detection by host's immune system
Antigenic variation
A new field has emerged which employs the power of computers to store, retrieve, and analyze DNA sequence data called
Bioinformatics
Replication Fork diagram. The top ( blue ) arrow is pointing to the ___________________ strand, and the bottom ( red ) arrow is pointing to the __________ strand. **** Replication fork highlights the differences between leading & lagging strands.****
Blank 1 : Leading Blank 2 : Lagging
RNA contains the sugar _________, which differs from its DNA counterpart by possessing _________ oxygen atom.
Blank 1 : Ribose Blank 2 : One more
Label A , B , and C. In the schematic of mRNA, Label A points to the ______site, label B depicts the ______ codon, and label C highlights the ______ codon.
Blank 1 : Ribosome binding Blank 2 : Start or Initiation Blank 3 : Stop, Termination, or Nonsense
In prokaryotes, the FIRST AUG after a ribosome binding site typically functions as a(n) __________________ codon. At other sites it simply encodes the amino acid _______________.
Blank 1 : Start or Initiation. Blank 2 : Methionine or met
In the most thoroughly studied example of bacterial conjugation, the term _____________ designates a donor cell with an F plasmid, whereas those cells who lack the F plasmid are termed _________
Blank 1: F+ Blank 2: F-
In general, the chromosome of a bacterial cell is _________ DNA molecule that is replicated _______.
circular; bidirectionally from one origin of replication
Two methods used to identify mutants in a culture are ______ and ______ selection.
direct; indirect
Cells that have the ability to take up DNA from the environment are called ______ cells.
Competent
A base substitution in a protein-encoding gene results in one of three possible mutation outcomes __________ mutation, ___________ mutation, ________ mutation.
Blank 1: silent or synonymous Blank 2: missense Blank 3: nonsense
Eukaryotic mRNA is first synthesized as an immature transcript called ____. It has to be processed significantly before it forms mature mRNA.
Pre mRNA
_____________ synthesizes RNA primer sequences.
Primase
True or false: A point mutation involves any substitution of a single nucleotide.
TRUE
Which of the following are the three main methods of gene transfer in bacteria?
transformation conjugation transduction