Microbiology CH.9

A small number of _______ are considered beneficial in that they provide the cell with a useful change in structure or physiology. Antibiotic resistance in bacteria is an example.

mutations

Building blocks of DNA, called ______, contain the same sugar and phosphate, but different nitrogenous bases.

nucleotides

When a cell is actively growing, the arg operon is Blank______, and arginine is Blank______.

on; actively synthesized

Which of the following signifies translation termination?

A nonsense codon is reached and the peptide is released from the ribosome

Which two of the following statements regarding plasmids are true?

Plasmids may contain genes that specify resistance to antibiotics. Many bacteria carry plasmids in addition to their chromosome.

In the central dogma, DNA encodes _______ encodes protein.

RNA

The antibiotic rifamycin, used to treat tuberculosis, binds and inhibits the activity of _________

RNA polymerase

The enzyme that transcribes DNA into RNA is ________ _________

RNA polymerase

True or false: DNA replication must occur prior to cell division to ensure that each new cell has a complete set of DNA chromosome(s).

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

A spontaneous mutation arises in DNA from ______.

errors in DNA replication

True or false: Bacterial conjugation is a sexual process.

false

True or false: The chromosome is a small circular segment of DNA found in the cytoplasm of prokaryotes that is capable of independent replication and usually contains nonessential genes.

false

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

false

The transfer of genes from donor to recipient in microorganisms, where the recipient strain shows a change in genetic makeup at the end, is referred to as _______

recombination

The transfer of genes from donor to recipient in microorganisms, where the recipient strain shows a change in genetic makeup at the end, is referred to as __________

recombination

What is the central dogma hypothesis of genetics?

DNA encodes RNA which encodes protein

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

Single or double stranded DNA or RNA

What is Horizontal gene transfer?

Transfer of DNA from a source other than the parent organisms

Most bacterial plasmids carry an origin of replication and at most ______ genes. Multiple choice question.

a few dozen

During conjugation, the donor cell generally retains a copy of the genetic material being transferred. This is termed a ______ process

conservative

The science of heredity is ______.

genetics

is the study of the inheritance of living things.

genetics

During conjugation, the two bacterial cells are connected by the conjugative _______.

pilus

A small circular segment of DNA found in the cytoplasm of bacteria that is capable of independent replication and usually contains nonessential genes is called a(n) ______.

plasmid

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

replication

The antibiotic rifamycin can be used to treat tuberculosis because _________

the drug is more active against bacterial RNA polymerase than the human enzyme

Which of the following are methods of gene transfer in bacteria?

Conjugation Transduction Transformation

Which of the following are areas of the genome where multiple genes exist that are coordinated to create a new trait, making the bacterium more pathogenic?

Pathogenicity islands

How does RNA differ from DNA in bacteria and eukaryotes?

RNA is single-stranded In RNA, uracil replaces thymine

How do an Hfr cell and an F+ cell differ?

The plasmid is integrated into the chromosome of an Hfr cell but not in an F+ cell.

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

conjugation

True or false: Mutations are always harmful to cells.

false

When organisms acquire genes which did not come directly from parent organisms it is referred to as ______ gene transfer.

horizontal

The lac operon in E. coli regulates the metabolism of ________

lactose

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

recombination

The different types of nucleotides in DNA contain:

the same sugar and phosphate, but different nitrogenous bases

The three methods of gene transfer in bacteria are _____ , ______ , _______

transformation, transduction, and conjugation

Which two of the following statements regarding eukaryotic transcription and RNA processing are correct?

A series of adenosines is added to the mRNA. Splicing to remove introns occurs in the nucleus.

True or false: Operons are found in fungi and helminths.

False

Which two statements regarding eukaryotic transcription and RNA processing are correct?

The exon-intron junction is recognized by a spliceosome. Transcription occurs before splicing.

What is vertical gene transfer?

Transfer of DNA from parent organisms during reproduction

Unlike DNA, RNA contains the nitrogenous base ______

Uracil

Mutations that occur because of errors in DNA replication are termed _______

spontaneous

DNA repair enzymes have as their substrate ______.

damaged DNA

Conjugation is a conservative process, meaning that ________

the donor retains a copy of the genetic material being transferred

During translation elongation, peptide bonds form between:

Amino acids

The genes of which microorganism(s) are arranged as operons?

Bacteria

The genes of the lac operon in E. coli encode enzymes that ______

catabolize lactose

True or false: A cell with an integrated F factor transmits its genes at lower frequency than does a cell with a free plasmid in the cytoplasm.

false

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

genome

Which test is a method of detecting mutagenic and potentially carcinogenic agents based upon the genetic alteration of nutritionally defective bacteria?

ames

DNA damage can be resolved by _______

enzymes

During replication, each parent DNA strand serves as a ______ for synthesis of new DNA strands.

template

Which term describes a sequence of three nucleotides that code for an amino acid in DNA?

Triplet

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

The arginine operon is "on" when the cell is ______.

actively growing

Detection of mutagenic and potentially carcinogenic agents based upon the genetic alteration of nutritionally defective bacteria is called the _____ test.

ames

A sequence of three consecutive nucleotide bases in DNA that encodes an amino acid is a(n) _______

codon

Horizontal gene exchange via a cellular bridge in bacteria is called _______.

conjugation

Ensuring that the DNA code will be maintained during cell growth and cell _______ is one of the two essential effects of the structure of DNA.

divison

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

mutation

Areas of the genome containing multiple genes which contribute to a new trait for the organism that increases its ability to cause disease are termed ______ ______.

pathogenicity islands

The process of bacteria turning on or off a group of genes that changes their phenotype in a heritable manner is called _____ _____.

phase variation

The process of bacteria turning on or off a group of genes that changes their phenotype in a heritable manner is called ______ _______

phase variation

Phase variation is when bacteria turn on or off a set off genes, which leads to obvious changes in their _______

phenotype

A mutation that affects only a single base pair in DNA is termed a(n) _______ mutation.

point

Which of the following is a type of mutation that affects only a single base pair in DNA?

point