Chap 9

The _________ test is used to determine the carcinogenic potential of a chemical

Ames

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

F factor

Genetic transfer of ______ to a methicillin-resistant Staphylococcus aureus (MRSA) strain produces vancomycin resistant enterococci (VRE).

a transposon containing the vanA operon

is another term for genetics--the study of inheritance in living things.

heredity

Which process repairs DNA that has been damaged by ultraviolet radiation using visible light?

Photoactivation

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

oncogenic

The mechanisms of ________ transformation involve genes that can regulate cellular genomes and control the onset of cell division.

oncogenic

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

Pili

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 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

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

Triplets

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

DNA encodes RNA which encodes protein

Genetic inheritance in microorganisms is best defined by which term?

Heredity

Mutations that involve the addition, deletion or substitution of no more than a few bases are referred to as ________ mutations

point

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

Triplet

The nitrogen bases in DNA are

*Adenine *Guanine *Cytosine *Thymine

The nitrogen bases in RNA are

*Adenine *Guanine *Cytosine *Uracil

DNA polymerases are responsible for

*Building the DNA chain. *Proofreading/repair.

The flow of genetic information in a cell is a process starting with ________ which encodes which encodes ________ protein.

*DNA *RNA or mRNA

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

*Environmental *Development

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.

*III *I

The enzyme involved in replicating a new DNA strand is DNA polymerase _____, and DNA polymerase _____ is involved in removing the RNA primer, closing gaps, and repairing mismatched bases.

*III, *I

Two components of an operon include the _______ that acts as an on/off switch, and the ______ gene sequences.

*Operator *Structural

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

The three types of RNA are______ RNA, ________ RNA, and _________RNA.

*rRNA *mRNA *tRNA

In a chromosome, the DNA is composed of ______ strands.

2

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

Genome

Which is the correct order of events when a protein is made in the process of translation?

Initiation, elongation, termination

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

Introns

A permanent inheritable alteration in the DNA sequence of a cell is a(n)

Mutation

The main enzyme responsible for transcription is

RNA polymerase.

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

Recombination

_____________ refers to the transfer of genes from donor to recipient microorganisms, where the recipient strain shows a change in genetic makeup at the end.

Recombination

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

Regulatory

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

Replication

The protein product of a repressor gene is the _________ which binds the operator to stop transcription.

Repressor

________ mutations in DNA are caused by random mistakes in replication and not known to be influenced by any mutagenic agent.

Spontaneous

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

Spontaneous mutation

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

Uracil

________ in bacteria refers to horizontal gene transmission via pili.

conjugation

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

corepressor

Proteins that remove incorrect bases and replace them with correct ones are termed ______ repair enzymes.

excision

The pentose sugar in DNA is

deoxyribose

True or false: Bacterial conjugation is a sexual process.

false

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

fertility

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

genome

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

mutations

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

replication

The _______ protein is capable of repressing an operon.

repressor

The pentose sugar in RNA is

ribose

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