Microbiology Chapter 8
A codon contains how many nucleotides?
3
gel electrophoresis separates DNA fragments using
electric current
What is a mutation?
A permanent inheritable alteration in the DNA sequence or content of a cell.
Which describes a plamsid?
A small circular piece of DNA that replicates its nonessential genes independently of the chromosome
Which of the following statements regarding conjugation is true?
After conjugation, the recipient cell will be F+
Which of the following are attributes of bacterial chromosomes?
Cells usually have one to three chromosomes. Circular DNA molecule
Genomes of cells are composed of... protein DNA RNA
DNA
What is the central theme of molecular biology?
DNA encodes RNA which encodes protein
Cellular genomes are composed of... DNA or RNA RNA only DNA only
DNA only
Removes the primer. closes gaps, and repairs mismatches
DNA polymerase 1
Adds bases the the growing DNA chain, proofreads
DNA polymerase 111
A(n) ____ cell has a separate fertility plasmid, whereas a(n) _____ cell has the F factor incorporated into its chromosome
F+; Hfr
True or False: Eukaryotic chromosomes are composed of DNA and RNA.
False
Transfer of DNA from a source other than the parent organisms
Horizontal gene transfer
Select all that apply Which of the following are attributes of eukaryotic chromosomes? Their DNA is tightly wound around histone proteins. They are linear, composed of double-stranded DNA. They are located in a cytoplasmic region called the nucleoid. The number of chromosomes in a eukaryotic cell can vary from a few to hundreds.
Their DNA is tightly wound around histone proteins. They are linear, composed of double-stranded DNA. The number of chromosomes in a eukaryotic cell can vary from a few to hundreds.
True or False: Only viruses can have an RNA genome.
True
True or false: The structure of DNA is essential for providing variety since the order of nucleotides is responsible for the unique qualities of each organism.
True
Transfer of DNA from parent organisms during reproduction
Vertical gene transfer
A single nucleotide polymorphism results from
a change in one base in a gene
Conjugation is a conservative process, meaning that....
a copy of the DNA being transferred is retained by the donor.
Which type of mutation has occurred when a gene that has undergone mutation reverses back to its original sequence
back mutation
The genes of which microorganism(s) are arranged as operons?
bacteria
Restriction endonucleases are enzymes which cut DNA at a specific palindromic sequence. They are produced
by bacteria to protect against viral infection
A _____ is a discrete cellular structure composed of an elongated DNA molecule.
chromosome
A discrete cellular structure composed of a neatly packaged DNA molecule is called a(n)
chromosome
Select all that apply Which of the following are attributes of bacterial chromosomes? circular DNA molecule enclosed in a membrane-bound organelle cells usually have one to three chromosomes organized by histone proteins
circular DNA molecule cells usually have one to three chromosomes
DNA that is made from RNA is called
complementary DNA
In bacteria, horizontal gene transmission through a pilus is called
conjugation
Three methods of gene transfer in bacteria
conjugation transformation transduction
____ involves the use of a connection bridge, _____ requires a bacterial virus vector, and _____ entails transfer of naked DNA
conjugation; transduction; transformation
Synthetic biology may be used to
create an operon using genes from different microbes create a cell whose entire chromosome was synthesized in vitro create an antibody with defined specificty
In the bacterium Escherichia coli, where is the chromosome located? plasmid cytoplasm nucleus
cytoplasm
What are the three components of a DNA nucleotide?
deoxyribose sugar phosphate nitrogenous base
In DNA, each nucleotide is composed of a sugar called ____, a nitrogenous _____, and a _____ group.
deoxyribose, base, phosphate
DNA replication involves all of these steps EXCEPT unzipping hydrogen bonds between complementary base pairs dissolution of the nuclear membrane synthesizing new DNA matching complementary base pairs uncoiling parent DNA
dissolution of the nuclear membrane
Ensuring that the DNA code is maintained during DNA replication and cell _____ is one of the essential effects of DNA structure.
division
Which is true regarding DNA semiconservative replication?
each new DNA helix contains one parent strand and one newly synthesized strand
True or false: DNA strands are parallel, running in the same orientation
false
Which type of mutation is generally most harmful to cells?
frameshift mutation
A faulty disease-causing gene is replaced with a gene from a healthy organism in the process called
gene therapy
The science of heredity is... biology reproduction genetics
genetics
The ____ is the sum total of genetic material in an organism. chromosome proteome gene genome
genome
Which term represents all of the genetic information within a cell? chromosome genome gene
genome
Unzips the DNA helix
helicase
How does RNA differ from DNA
in RNA, uracil replaces thymine. RNA is usually single-stranded.
Where are chromosomes of yeast cells located? in the nucleus on the rough ER free in the cytoplasm
in the nucleus
Which type of mutation results from exposure to a mutagen?
induced mutation
A sequence of DNA in a eukaryotic gene that does not code for protein is called a(n)
intron
eukaryotic mRNA contain non-coding regions called
introns
Seals nicks in DNA
ligase
A change in the genetic code that leads to the insertion of a different amino acid in a protein is called a
missense mutation
Eukaryotic chromosomes are located in/on the ____ of the cell endoplasmic reticulum cytoplasm nucleoid nucleus
nucleus
Eukaryotic chromosomes are located in the ____, while prokaryotic chromosomes are found in the _____.
nucleus; nucleoid
Which unit in bacteria consists of a regulatory gene, a control region, and structural genes?
operon
Bacterial and archaeal genes are arranged into
operons
Phase variation is a type of _____ variation
phenotypic
Donor and recipient bacterial cells are connected by the sex _____ during conjugation.
pilus
The process occurring in this image is the
polymerase chain reaction
Synthesizes an RNA primer
primase
The type of macromolecule that is formed from long chains of amino acids produced in translation is a(n)
protein carbohydrate lipid polypeptide transcription
An event in which one bacterium donates DNA to another bacterium, resulting in a strain that differs from both donor and recipient, is a type of genetic transfer called
recombination
During ______, the DNA is duplicated prior to binary fission.
replication
The process of duplicating is called DNA _____ replication transcription translation
replication
A mutation that alters the DNA sequence of a gene, but does not change the amino acid sequence of the protein that is encoded by the gene is called a(n)
silent mutation
Creating new biological molecules and organisms from scratch is in the realm of
synthetic biology
All of the following are true regarding eukaryotic chromosomes EXCEPT
the chromosomes are located in the nucleoid
The lactose operon itself has three important features. Which of the following is NOT one of these features? the regulator the control locus the inducer the structural locus
the inducer
Untangles newly replicated strands
topoisomerase
Which two types of horizontal gene transfer do NOT require direct contact between the donor and the recipient cells?
transduction and transformation
synthesizing amino acid sequences from messenger RNA is called
translation
Which group of microbes has representatives with either an RNA or DNA genome? bacteria fungi helminths viruses
viruses
The native or _____ type strain exhibits nonmutated characteristics.
wild type