Chapter 9: Genetics

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

excision

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

oncogenic

A permanent inheritable alteration in the DNA sequence of a cell is a _____.

mutation

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

triplets

Mutations are always harmful to cells.

False

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

Corepresser

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

False

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

Regulatory

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

Spontaneous mutation

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

Operator and structural genes

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

initiation; elongation; termination

The DNA of a chromosome is _____-stranded.

double

The three types of RNA are _____RNA, _____RNA, and _____RNA.

m;t;r

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

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

vanA; transposon

A _____ binds to an inactive repressor to make an active repressor.

corepressor

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

Replication

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

Initiation, elongation, termination

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

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

environmental; development

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

point

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

represser

The _____ protein is capable of repressing an operon.

repressor

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

2

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

oncogenic

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

operator; structural

A _____ is a small circular segment of DNA found in the cytoplasm of bacteria that is capable of independent replication and usually contains nonessential genes?

plasmid

During semi-conservative _____ the DNA is duplicated prior to binary fission.

replication

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 _____ test is used to determine the carcinogenic potential of a chemical.

Ames

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

DNA encodes RNA which encodes protein

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

DNA; RNA

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

Genome

Genetic inheritance in microorganisms is best defined by which term?

Heredity

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

Heredity

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

Introns

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

Introns

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

Photoactivation

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 main enzyme responsible for transcription is __________.

RNA polymerase

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

Single and double-stranded DNA or RNA

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

Spontaneous

What is the purpose of the Ames test?

To determine the carcinogenic potential of a chemical

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

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

a transposon containing the vanA operon

Which of the following is NOT a type of RNA?

dRNA