Microbiology Chapter 9

Mutations are always harmful to cells.

False

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. Multiple choice question.

III I

_______ RNA may exert control on several levels in both prokaryotes and eukaryotes.

Regulatory

Which are components of an operon in a sequence of DNA?

Structural genes Regulatory region

Donor and recipient bacterial cells are connected by the sex pilus during

conjugation

______ in bacteria refers to horizontal gene transmission via pili.

conjugation

An inactive repressor binds to a(n) _____ to make an active repressor

corepressor

What binds to an inactive repressor to make an active repressor?

corepressor

Which of the following is NOT a type of RNA?

dRNA

The DNA of a chromosome is _______- stranded

double

In eukaryotic cells, gene expression is regulated in response to _____ stimuli such as nutrient and toxin levels, and is also during growth and _____

environmental development

One DNA repair mechanism that removes incorrect bases, and replaces them with correct ones, is the ______ repair mechanism.

excision

A donor cell with a F (fertility) ______ is considered F+ in bacterial conjugation

factor

A recipient cell having no F (fertility) ______ is considered F- in bacterial conjugation

factor

Bacterial conjugation is a sexual process.

false

Viral genomes are always composed of either single or double stranded DNA.

false

DNA sequences found within a gene that do not encode the protein corresponding to the gene are

introns

Which DNA sequences are found within a gene but do not encode the protein specified by that gene?

introns

The three types of RNA that are directly involved in making protein are _______ RNA, _______ RNA, and ______ RNA

messenger transfer ribosomal

A small number of _____ are considered beneficial in that they provide the cell with a useful change in structure or physiology.

mutations

The complete set of chromosomes and genes in an organism is referred to as the

genome

Which term represents all of the genetic information within a cell?

genome

Several DNA viruses are known to be initiators of cancers and are thus termed

oncogenic

Another term for genetics is

heredity

Genetic inheritance in microorganisms is best defined by which term?

heredity

The first three events of translation in the correct order are _____, _____, _______ followed by the protein folding and processing

initiation elongation termination

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

Mutations that involve the addition, deletion, or substitution of one or a few bases are referred to as ______ mutations.

point

Which process uses visible light to repair DNA that has been damaged by ultraviolet radiation?

photoactivation

Donor and recipient bacterial cells are connected by the sex _____ during conjugation

pilli

Two components of an operon include the ______ region and the ______ gene sequences.

regulatory structural

During semiconservative _________ the DNA is duplicated prior to binary fission.

replication

The enzymes responsible for building the DNA strand, proofreading newly produced DNA strands, and removing the RNA primer are DNA _______ I and III

polymerase

What must occur prior to cell division to ensure that each new cell has a complete set of DNA chromosome(s)?

replication

DNA polymerases are responsible for

proofreading/repair. building the DNA chain.

When one bacterium donates DNA to other bacterium, it is known as

recombination

Which term refers to the transfer of genes from donor to recipient microorganisms?

recombination

The feature of the lac operon that is capable of stopping the activity of the operon is a(n)

repressor

The protein which is capable of stopping the output of product encoded by the lac operon is called a(n)

repressor

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

Which type of mutation is due to random mistakes in replication?

spontaneous mutation

The term _____, or codon, is a sequence of 3 nucleotides in DNA that encodes an amino acid

triplet

Which term, synonymous with codon, describes a trinucleotide sequence coding an amino acid in DNA?

triplet

A mutation is an alteration in the DNA sequence or content of a cell that is passed on when the cell divides.

true

The nitrogenous base thymine is only found in DNA, while ______ is only found in RNA

uracil

Which nitrogenous base is found in RNA but not found in DNA?

uracil

Vancomycin-resistant enterococci (VRE) arise when, through genetic transfer, a MRSA strain acquires the ________ operon located within a ______ .

vanA transposon

In a chromosome, the DNA is composed of _____ strands

2

The carcinogenic potential of a chemical can be determined by the _____ test

Ames

The flow of genetic information in a cell is a process starting with ______ which encodes _____ which encodes protein

DNA RNA

Which best describes the flow of genetic information in a cell?

DNA encodes RNA which encodes protein

What is the name of the specialized plasmid that directs conjugation in gram-negative cells?

F factor

Conjugation in gram-negative cells is directed by a plasmid called the _______ factor

F or fertility

In bacterial conjugation, which term refers to a recipient cell that does not have a fertility plasmid?

F-

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.

III,I

Which is the correct order of events when a protein is made in the process of translation, starting with the first event?

Initiation, elongation, termination

The main enzyme responsible for transcription is:

RNA polymerase

Which of the following is the genetic pattern of viral genomes?

Single or double stranded DNA or RNA

Which of the following are functions of RNA polymerase?

Synthesizes an RNA molecule from DNA template Unwinds the DNA so that transcription can take place

What is the purpose of the Ames test?

To determine the carcinogenic potential of a chemical

Methicillin-resistant Staphylococcus aureus (MRSA) strain produces vancomycin resistant enterococci (VRE) with the gene transfer of

a transposon containing the vanA operon

Viral initiators of cancer are termed

oncogenic