microbiology chapter 9 questions

How do an Hfr cell and an F+ cell differ? F+ cells have more plasmids than Hfr cells. The plasmid is integrated into the chromosome of an F+ cell but not in an Hfr cell. Hfr cells have larger plasmids than F+ cells. The plasmid is integrated into the chromosome of an Hfr cell but not in an F+ cell.

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

Which recombination method involves transfer of DNA via bacteriophages? Transduction Conjugation Transposition

Transduction

Which of the following are methods of gene transfer in bacteria? Transduction Transcription Translation Conjugation Transformation

Transduction Conjugation Transformation

Most bacterial plasmids carry an origin of replication and at most _____ genes. a few hundred a few thousand a few dozen

a few dozen

The arginine operon is "on" when the cell is actively growing slowing down dormant

actively growing

What did Griffith's experiment using Streptococcus pneumoniae demonstrate? That S. pneumoniae was the cause of pneumonia in mice That nonencapsulated S. pneumoniae were more virulent than heat-killed strains That DNA released from a dead cell can be transferred to live cell

That DNA released from a dead cell can be transferred to live cell

Which two statements regarding eukaryotic transcription and RNA processing are correct? A series of thymines is added to the mRNA. The exon-intron junction is recognized by a spliceosome. Transcription occurs before splicing. Splicing to remove introns occurs in the cytoplasm.

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

In bacterial conjugation, which type of donor has the fertility factor integrated into the chromosome? F+ F- Hfr

Hfr

The genes of the lac operon in E. coli encode enzymes that catabolize glucose catabolize lactose anabolize lactose catabolize lactic acid

catabolize lactose

A bacterial cell described as ______ can accept soluble DNA from the surrounding environment.

competent

True or false: Bacterial conjugation is a sexual process.

false

True or false: In bacterial conjugation, all F+ donor cells are high frequency recombinant (Hfr) cells. True False

false

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

false

______ is the study of the inheritance of living things.

genetics

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

nucleotides

An organism that contains and expresses genes that originated in another organism is called a(n) heterotroph recombinant donor variant

recombinant

Conjugation is a conservative process, meaning that the recipient replicates the DNA immediately upon receiving it the donor retains a copy of the genetic material being transferred the DNA is transferred intact, without any mutations the donor transfers only the minimum to the recipient

the donor retains a copy of the genetic material being transferred

The process of introducing foreign genes to a plant cell by adding the DNA directly to the cell medium is termed _____-

transfection

During translation elongation, peptide bonds form between: RNA nucleotides DNA and RNA nucleotides DNA nucleotides Amino acids

amino acids

______ 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

Conjugation ______ and transduction are methods of gene transfer in bacteria.

transformation

True or false: A bacterial cell described as competent can accept soluble DNA from the surrounding environment.

true

True or false: The parent strands in a DNA molecule are used as a template to synthesize a complementary strand of DNA. True False

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 False

true

Unlike DNA, RNA contains the nitrogenous base ______

uracil

Which is the main event of translation termination? A nonsense codon is reached and the peptide is released from the ribosome A terminator sequence is reached and mRNA is released from the DNA template tRNA leaves the E site on the ribosome

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

Which enzyme adds nucleoside triphosphates to a growing DNA strand? DNA polymerase RNA polymerase Primase

DNA polymerase

Which is true regarding DNA replication? RNA polymerase copies new DNA bases during this process. The new strand is synthesized in the 5' to 3' direction on the leading strand, and in the 3' to 5' direction on the lagging strand. Each new DNA helix contains one parent strand and one newly synthesized strand The lagging strand is synthesized continuously

Each new DNA helix contains one parent strand and one newly synthesized strand

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.

division

When a cell is actively growing, the arg operon is _____, and arginine is _____. on; actively synthesized off; consumed in biosynthesis on; consumed in biosynthesis off; actively synthesized

on; actively synthesized

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

DNA transfer between bacterial cells typically involves DNA in the form of ______ and ______. enveloped viruses plasmids nucleotides chromosomal fragments

plasmids chromosomal fragments

A mutation that affects only a single base pair in DNA is termed a ______ mutation.

point

DNA _________ is the enzyme that synthesizes DNA strands in the 5' to 3' direction.

polymerase

During replication initiation, the enzyme ______ synthesizes primer sequences.

primase

RNA ______ are structures that provide DNA polymerase with the 3' end needed for synthesis during DNA replication.

primers

Small chromosomal DNA fragments or plasmids are the forms of DNA most often ______. exchanged between bacteria transferred between bacteria expressed by bacteria

transferred between bacteria

Which two of the following statements regarding eukaryotic transcription and RNA processing are correct? Transcription occurs after splicing. Splicing to remove introns occurs in the nucleus. The exon-intron junction is recognized by a ribosome. A series of adenosines is added to the mRNA.

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

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

Bacteria

What is the central dogma hypothesis of genetics? DNA encodes RNA which encodes protein Protein encodes RNA which encodes DNA RNA encodes DNA which encodes protein

DNA encodes RNA which encodes protein

Which two statements are correct regarding DNA replication elongation? DNA ligase joins the lagging strand fragments. Topoisomerases catalyze the formation of a phosphodiester bond. DNA polymerase I removes the RNA primers used to initiation synthesis. DNA polymerase III removes the RNA primers used to initiation synthesis

DNA ligase joins the lagging strand fragments. DNA polymerase I removes the RNA primers used to initiation synthesis.

Which enzyme adds nucleoside triphosphates to a growing DNA strand? RNA polymerase Primase DNA polymerase

DNA polymerase

Which is the main enzyme in elongation of a DNA strand during replication? DNA polymerase Primase DNA ligase

DNA polymerase

Which two of the following statements are correct regarding DNA replication elongation? DNA polymerase III joins the lagging strand fragments. DNA polymerase I removes the RNA primers used to initiate DNA synthesis. Topoisomerases catalyze the formation of a phosphodiester bond. Replication proceeds at a rate of 750 bases per second.

DNA polymerase I removes the RNA primers used to initiate DNA synthesis. Replication proceeds at a rate of 750 bases per second.

Which two statements are correct? DNA polymerases relieve the superhelical tension as DNA is replicated. Eukaryotes initiate replication from multiple origins of replication. Telomere DNA gets progressively shorter with each copy. Both eukaryotic and bacterial DNA is circular and the replication mechanisms are nearly identical.

Eukaryotes initiate replication from multiple origins of replication. Telomere DNA gets progressively shorter with each copy.

Which two of the following statements are correct? Telomere DNA gets progressively longer with each copy. Eukaryotic DNA is linear whereas bacterial DNA is circular. Both types of DNA initiate replication from a single origin of replication. Topoisomerases relieve the superhelical tension as DNA is replicated.

Eukaryotic DNA is linear whereas bacterial DNA is circular. Topoisomerases relieve the superhelical tension as DNA is replicated.

In bacterial conjugation, a recipient cell having no ______ plasmid is considered F-.

F

In bacterial conjugation, which term refers to a donor cell with a fertility plasmid located in the cytoplasm? F- F+ Hfr

F+

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

F-

True or false: Okazaki fragments are formed during DNA replication of the leading strand. True False

False

Which two of the following statements regarding plasmids are true? A typical bacterial plasmid will have a few hundred genes. Many bacteria carry plasmids in addition to their chromosome. Plasmids are essential for bacterial survival. Plasmids may contain genes that specify resistance to antibiotics.

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

In replication of DNA, the lagging strand is replicated in a discontinuous manner forming _______ fragments.

Okazaki

Which enzyme synthesizes primer sequences during replication initiation? DNA polymerase I Primase Topoisomerase DNA polymerase III

Primase

During DNA replication, why are primer sequences necessary? Primer sequences stabilize the open helix during replication Primase needs a primer to add DNA nucleotides to a growing strand Helicase won't function in the absence of a primer sequence Primers provide DNA polymerase with the 3' end needed for synthesis

Primers provide DNA polymerase with the 3' end needed for synthesis

How does RNA differ from DNA in bacteria and eukaryotes? In RNA, thymine is replaced with adenine Ribose in RNA contains one less carbon than deoxyribose in DNA. RNA is single-stranded In RNA, uracil replaces thymine

RNA is single-stranded In RNA, uracil replaces thymine

Which enzyme transcribes DNA into RNA? DNA polymerase RNA polymerase Reverse transcriptase

RNA polymerase

Which of the following is the genetic pattern of viral genomes? Double stranded DNA only Single or double stranded DNA or RNA Single stranded DNA only Single or double stranded DNA only

Single or double stranded DNA or RNA

True or false: During DNA replication, both the leading and lagging strands are synthesized in the 5' to 3' direction. True False

true

During which method of gene transfer are bacterial cells in direct contact? conjugation transformation transduction

conjugation

R factors are specifically associated with which mechanism of recombination? Transformation Conjugation Transduction

conjugation

_______ in bacteria refers to horizontal gene exchange via pili.

conjugation

During conjugation, the donor cell generally retains a copy of the genetic material being transferred. This is termed a _____ process. semiconservative conservative translational recombinant

conservative

A recombinant is defined as an organism that contains and expresses the recA gene maintains two copies of its genetic material contains and expresses genes that originated in another organism has been genetically modified for biotechnology purposes

contains and expresses genes that originated in another organism

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

duplication

A spontaneous mutation arises in DNA from errors in DNA replication transposable elements moving in the chromosome gene expression treatment with ultraviolet light

errors in DNA replication

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

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. True false question.

false

In _____ transduction, random fragments of host DNA are taken up by the bacteriophage during assembly. generalized specialized

generalized

The two versions of transduction are generalized transduction specialized transduction replicative transduction conjugative transduction

generalized transduction specialized transduction

The science of heredity is ______. reproduction genetics biology

genetics

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? Chromosome Gene Genome

genome

Select the enzymes that function in DNA replication. reverse transcriptase helicase RNA polymerase ligase DNA polymerase

helicase ligase DNA polymerase

In DNA replication, _____ unwinds the double helix, primase synthesizes the short RNA primer and DNA _______ adds nucleotides to the new chain

helicase polymerase

_____ gene transfer occurs when organisms acquire genes which did not come directly from parent organisms.

horizontal

Which strand is replicated discontinuously in segments during DNA replication? Lagging Leading

lagging

Which strand is replicated continuously without segments during DNA replication? Leading Lagging

leading

The final sealing of nicks in a newly synthesized DNA strand is catalyzed by the enzyme _______

ligase

Which enzyme completes the final sealing of nicks in a newly synthesized DNA strand? RNA polymerase DNA polymerase Ligase Helicase

ligase

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

mutation

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

mutations

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

pillus

In bacterial conjugation, a donor cell with a F (fertility) _______ located in the cytoplasm is considered F+.

plasmid

During ______ DNA replication, the newly made double helices are composed of one parent template and one newly synthesized strand.

semiconservative

In _____ transduction, a particular part of the host genome is included in the virus. specialized generalized

specialized

Mutations that occur because of errors in DNA replication are termed replicative spontaneous transposable induced

spontaneous

The parent strands in a DNA molecule are used as a ______ to synthesize a complementary strand of DNA.

template

All DNA nucleotides contain ______. the same nitrogenous base, but different phosphates and sugars the same sugar and phosphate, but different nitrogenous bases the same sugar, but different phosphates and nitrogenous bases the same nitrogenous base and phosphate, but different sugars

the same sugar and phosphate, but different nitrogenous bases

The two bacteria in a transduction must be the same species because DNA cannot be transferred if it is from a different species they must make cell to cell contact the virus is specific for a particular species DNA cannot be expressed if it is from a different species

the virus is specific for a particular species

Griffith's experiment using Streptococcus pneumoniae demonstrated the process of _______. conjugation transformation replication

transformation

Which gene transfer method involves the uptake of free DNA by competent bacterial cells? Transformation Transduction Transposition Conjugation

transformation

The term ______ is a sequence of 3 consecutive nucleotide bases in DNA that encodes an amino acid.

triplet

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

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 False

true

True or false: A phage is a bacterial virus. True False

true

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 False

true