Microbiology Exam 4- Genetics

Which of the following antibiotics will not inhibit protein synthesis?

Penicillin

The enzyme which forms a peptide bond between amino acid is

Peptidyl transferase

Thymidine dimers are removed by the enzymes

Photolyase and exonuclease

Which of the following best describes translation? DNA -> DNA RNA -> Protein DNA -> RNA DNA -> Protein RNA -> DNA

RNA -> Protein

The correct structure of DNA components can be presented as phosphate-base-sugar. phosphate-sugar-phosphate-base. base-sugar-phosphate-base. base-phosphate-sugar. phosphate-sugar-base.

phosphate-sugar-base.

Arrange the following proteins in the proper order in which they participate in DNA replication. 1 = Primase 2 = Helicase 3 = Single-strand binding proteins 4 = DNA polymerase I 1, 2, 3, 4 1, 3, 2, 4 2, 4, 3, 1 2, 3, 1, 4 2, 3, 4, 1

2, 3, 1, 4

Which of the following DNA sequences is complementary to 5' TAGAC 3'? 5' ATCTG 3' 5' CAGAT 3' 5' GTCTA 3' 5' TAGAC 3' none of the above

5' GTCTA 3'

Which of the following sequences are base analogs?

5-bromo uracil

According to Chargaff's rule, which of the following statements about double-stranded DNA is NOT true? A + G = T + C A = T and C = G A + T = C + G

A + T = C + G

Which of the following sequences will be affected by UV radiation?

ATTCGGCAG

The start codon for protein synthesis is:

AUG

Which of the following is a characteristic of double-stranded DNA? 10 base pairs per turn 2 nanometers in width All of these are characteristic of DNA. 0.34 nanometers per basepair

All of these are characteristic of DNA.

Which of the following is required to replicate the lagging strand of DNA? All of these are required. Okazaki fragments DNA ligase primase

All of these are required.

If the codon for valine is GUU, what will be the anticodon of the tRNA that will transfer Val?

CAA

In eukaryotic cells, what cellular structure is composed of a neatly packaged DNA molecule? Genotype Genome Chromosome Histone Gene

Chromosome

Which of the following best describes transcription? DNA -> RNA RNA -> Protein RNA -> DNA DNA -> DNA DNA -> Protein

DNA -> RNA

Which of the following best describes transcription? RNA -> Protein DNA -> RNA DNA -> DNA RNA -> DNA DNA -> Protein

DNA -> RNA

RNA primers are removed by the action of the enzyme phophodiesterase. DNA polymerase I. DNA polymerase III. helicase. primase.

DNA polymerase I.

The enzyme that travels along the leading strand assembling new nucleotides on a growing new strand of DNA is... DNA polymerase. DNA polymerase III. RNA primase. helicase. DNA ligase.

DNA polymerase.

Please select all of the characteristics of DNA to test your understanding of its chemical structure. Deoxyribose sugar Ribose sugar Phosphate group Nitrogenous bases Ionic bonds

Deoxyribose sugar Phosphate group Nitrogenous bases

Before DNA replication can occur, the OH bonds between the strands must be broken. True False

False

Codons are found on tRNA, and anticodons are found on mRNA. True False

False

DNA pol III can initiate DNA synthesis. True False

False

DNA replication does not require a template. True False

False

During DNA replication, the lagging strand is synthesized continuously, while the leading strand is synthesized discontinuously. True False

False

Initial attachment of the transcription enzyme to the gene, results in a structure termed the closed complex. True False

False

One DNA strand is used as the template to make two new strands of DNA. True False

False

The bacterial chromosome is linear. True False

False

The newly-synthesized strand of DNA has exactly the same base sequence as that of its template strand. True False

False

The products of protein synthesis are exclusively enzymes and enzyme products. True False

False

The sequence for protein synthesis is translation, then transcription. True False

False

The terminator of a gene is located upstream of the coding region. True False

False

To allow simultaneous replication of the leading and lagging strands by dimeric DNA pol III, the DNA of the leading strand has to be folded. True False

False

Transformation is a mode of genetic recombination in which a plasmid is transferred from a donor cell to a recipient cell via a direct connection. True False

False

Unwinding of the DNA during transcription is the result of the activity of a helicase enzyme downstream of the RNA polymerase. True False

False

Addition or deletion of bases that changes the reading of mRNA codons

Frameshift Mutation

Result from exposure to known mutagens, which are primarily physical or chemical agents that damage DNA

Induced Mutation

Transcribed version of a structural gene or genes in DNA

Messenger RNA

Please choose all of the statements that are true regarding transcription and translation in prokaryotes. Prokaryotic mRNAs often contain information from several genes in series. Prokaryotic mRNA must be processed by excising introns before translation takes place. Transcription and translation can occur at the same time in prokaryotes. Transcription occurs in the nucleus of prokaryotes. Translation occurs in the cytoplasm of prokaryotes.

Prokaryotic mRNAs often contain information from several genes in series. Transcription and translation can occur at the same time in prokaryotes. Translation occurs in the cytoplasm of prokaryotes.

The enzyme that accomplishes transcription is termed DNA polymerase. DNA ligase. RNA polymerase. RNA ligase. RNA replicase.

RNA polymerase.

Before the lagging strand can begin assembling new DNA nucleotides, which of the following must occur? DNA polymerase III adds deoxyribonucleotides. RNA primase constructs a short RNA primer. DNA polymerase I removes some material and replaces it with DNA. DNA ligase forms a phosphodiester bond between the 3' OH of the growing strand and the 5' phosphate in front of it. OH bonds must be broken between the two strands of DNA.

RNA primase constructs a short RNA primer.

Forms a complex cellular structure that contributes to the process of translation

Ribosomal RNA

Random change in the DNA arising from errors in replication that occur without a known cause

Spontaneous mutation

Changing of single base in the DNA code that may result in the placement of a different amino acid

Substitution Mutation

Contains the anticodon and an amino acid binding site

Transfer RNA

A structural gene encodes the information for a specific protein. True False

True

After DNA replication two identical DNA molecules are formed. True False

True

DNA mutations are passed on to a cell's progeny. True False

True

DNA photolyase is a light-sensitive enzyme able to repair DNA damaged by ultraviolet radiation. True False

True

More than one codon can code for an amino acid. True False

True

More than one ribosome can attach to the mRNA and translate the mRNA to protein True False

True

Plasmids are small pieces of DNA that may carry genetic information for antibiotic resistance. True False

True

The DNA replication machinery is assembled at the replication fork. True False

True

The RNA transcript being produced by the RNA polymerase is complementary to the template strand of the DNA. True False

True

The amino acid sequence of a protein determines its shape and specific function. True False

True

The genetic code for frog, bacteria, and aspergillus are the same. True False

True

The lac operon is normally in an off mode and does not initiate enzyme synthesis when the appropriate substrate is absent. True False

True

The lac repressor protein is active in the absence of lactose within the cell. True False

True

The polycistronic mRNA is transcribed from the lac operon when lactose is present in the cell. True False

True

Which of the following is NOT a nitrogen base found in DNA? Cytosine Thymine Adenine Uracil Guanine

Uracil

Transcription is characterized by... a transfer RNA molecule synthesized from the DNA molecule in the nucleus. the binding of enzymes to their substrates to produce products. a ribosomal RNA molecule synthesized from the DNA molecule in the nucleus. a messenger RNA molecule synthesized from the DNA molecule in the nucleus. the blueprint of the RNA molecule used to bind amino acids together to form proteins.

a messenger RNA molecule synthesized from the DNA molecule in the nucleus.

DNA replication in bacteria begins at a single origin and proceeds in one direction. many origins and proceeds in one direction. a single origin and proceeds in both directions. two origins and proceeds in both directions. many origins and proceeds in one direction.

a single origin and proceeds in both directions.

The lac repressor is inactivated by binding to which of the following? betagalactosidase transcription factors allolactose glucose lactose

allolactose

Nucleotides are the building blocks of neither DNA nor RNA. RNA only. both DNA and RNA. DNA only. cells.

both DNA and RNA.

When the defective phage enters a new bacterial cell both phage DNA and bacterial DNA integrate into the chromosome of the new cell host only phage DNA integrates into the chromosome of the new host cell the DNA is destroyed only bacterial DNA from the previous bacterial host integrates into the chromosome of the new host cell

both phage DNA and bacterial DNA integrate into the chromosome of the new cell host

A mutation that causes a change in a single nucleotide in DNA will have no effect on the resulting protein causes protein synthesis to stop causes the codon to be correct, but the anticodon to be incorrect changes the corresponding nucleotide in mRNA, resulting in a different codon

changes the corresponding nucleotide in mRNA, resulting in a different codon

Mutation is-

changing the nucleotide sequence of DNA

The genetic material in bacteria is single-stranded RNA. double-stranded RNA. single-stranded DNA. double-stranded DNA. either A or B

double-stranded DNA.

Semiconservative replication of DNA means only one strand is used as a template a double-stranded DNA is split into two single-stranded DNAs each DNA made contains one old strand and one new strand of DNA only half the genes are copied into the new cells

each DNA made contains one old strand and one new strand of DNA

In DNA replication only one strand of DNA is used as a template a single strand of DNA is copied to make two single strands of DNA each strand replicates in a different direction both strands replicate in the same direction

each strand replicates in a different direction

Which of the following occurs first in transcription? elongation of the mRNA formation of a holoenzyme formation of an open complex action of the Rho protein formation of a closed complex

formation of a holoenzyme

The ______ is the sum total of genetic material in a cell. genetics phenotype genome heredity

genome

The enzyme that unwinds a segment of the DNA molecule is... DNA polymerase. RNA primase. DNA ligase. helicase. DNA polymerase III.

helicase.

When one bacterium donates DNA to another bacterium, a type of genetic recombination known as _________ has occurred. vertical gene transfer horizontal gene transfer transposition sexual reproduction

horizontal gene transfer

Which of the following is correct regarding sigma factor? it recognizes the promoter region it forms mRNA it is involved in the termination of replication it forms an open complex none of the above are correct

it recognizes the promoter region

The lac repressor binds to what site within the lac operon? lacA lacO lacl lacZ lacP

lacO

Which of the following is not part of the lac operon? lacO lacA lacl lacP lacZ

lacl

Genetic ______ and the variations they produce result in population changes and thus, evolution. regulations mutations translations operons

mutations

A(n) _______ is a section of prokaryotic DNA that contains one or more genes along with a corresponding operator to control transcription. repressor transposon promoter operon

operon

DNA replication begins at a specific site called the origin initiator promoter replicator start codon

origin

The transcription enzyme first attaches to the ________ of the gene. coding region operator regulator initiator promoter

promoter

Transposons are... transposable elements. segments of DNA. plasmids. segments of messenger RNA. segments of transfer RNA.

segments of DNA.

DNA replication is said to be dispersive. semi-conservative. conservative. none the above liberal.

semi-conservative.

DNA replication is said to be inconclusive. dispersive. semi-conservative. liberal. conservative.

semi-conservative.

The donor chromosome is transferred as... double stranded DNA. single stranded DNA. single stranded RNA. double stranded RNA. a plasmid.

single stranded DNA.

Anticodons are group of 3 nucleotides found in:

tRNA

The Rho protein is involved in the _____ stage of transcription. none of the above elongation initiation termination

termination

Translation is characterized by... a transfer RNA molecule synthesized from the DNA molecule in the nucleus. the binding of enzymes to their substrates to produce products. the blueprint of the RNA molecule used to bind amino acids together to form proteins. a messenger RNA molecule synthesized from the DNA molecule in the nucleus. a ribosomal RNA molecule synthesized from the DNA molecule in the nucleus.

the blueprint of the RNA molecule used to bind amino acids together to form proteins.

Which of the following is a true statement concerning protein synthesis? translation occurs in the nucleus and transcription occurs in the cytoplasm. transcription occurs in the nucleus and translation occurs in the mitochondria. for every RNA produced, there is an enzyme or enzyme product produced. transcription occurs in the nucleus and translation occurs in the cytoplasm. translation occurs in the nucleus and transcription occurs in the mitochondria.

transcription occurs in the nucleus and translation occurs in the cytoplasm.

The transfer of DNA from one bacterial cell to another using virus is

transduction

The acceptance by a bacterial cell of small DNA fragments from the surrounding environment is termed ________. transposition transduction conjugation transformation

transformation

Which of the following does NOT occur during bacterial conjugation? shortening of the pilus unidirectional transfer of both DNA strands enzymatic cleavage of one strand at the origin of transfer recipient cell becomes a donor cell after conjugation direct contact between donor and recipient cells

unidirectional transfer of both DNA strands