Question 1

A bacteriophage transfers a random fragment of DNA of the previous host to the current host.This is an example of

Accepted Answer

A) conjugation. 
B) generalized transduction. 
C) specialized transduction. 
D) the creation of an Hfr cell.

Question 2

In Griffith's experiments with Streptococcus pneumoniae, rough nonencapsulated streptococci were converted into smooth encapsulated streptococci in the presence of the heat-killed smooth encapsulated streptococci.Which microbial process had Griffith identified?

Accepted Answer

A) Transduction 
B) Conjugation 
C) Transformation 
D) Cloning

Question 3

The expression of genetic traits is referred to as the organism's ______.

Accepted Answer

A) genome 
B) genotype 
C) proteome 
D) phenotype 
E) proteotype

Question 4

If a codon for alanine is GCA, then the anticodon is ______.

Accepted Answer

A) GCA 
B) CGT 
C) ACG 
D) CGU 
E) UGC

Question 5

Split genes

Accepted Answer

A) are common in bacteria and eukaryotes. 
B) only have exons initially transcribed to mRNA. 
C) have introns located only at the beginning and end of a coding region. 
D) are acted upon by spliceosomes to excise introns and then join exons.

Question 6

Which of the following is not true of transposons?

Accepted Answer

A) They can change pigmentation. 
B) They can replace damaged DNA. 
C) They can transfer drug resistance. 
D) They can change the genome. 
E) They are always part of plasmids.

Question 7

Recombinant organisms are those that have received new DNA in the form of a conjugated plasmid; genetically engineered cells are not considered recombinant.

Accepted Answer

A) True 
 B)False

Question 8

Proteomics is the study of all proteins that are expressed by an organism, whereas genomics refers to the study of the organism's entire genome, not simply the protein-coding regions.

Accepted Answer

A) True 
 B)False

Question 9

The duplication of a cell's DNA is called _______.

Accepted Answer

A) mitosis 
B) replication 
C) transcription 
D) translation 
E) mutation

Question 10

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

Accepted Answer

A) copy point 
B) template 
C) comparison molecule 
D) scaffold 
E) reservoir

Question 11

A mutation that changes a normal codon to a stop codon is called a ______ mutation.

Accepted Answer

A) point 
B) silent 
C) back 
D) missense 
E) nonsense

Question 12

DNA gyrase

Accepted Answer

A) copies DNA bases. 
B) synthesizes RNA primers. 
C) closes gaps between DNA bases. 
D)  removes supercoiling ahead of origin.

Question 13

Eukaryotic chromosomes differ from bacterial chromosomes because only eukaryotes have

Accepted Answer

A) histone proteins. 
B) chromosomes in a nucleus. 
C) several to many chromosomes. 
D) elongated, not circular, chromosomes. 
E) All of the choices are correct.

Question 14

All of the following pertain to nitrogenous bases except

Accepted Answer

A) they form pairs by hydrogen bonding. 
B) guanine pairs with uracil. 
C) adenine pairs with thymine. 
D) cytosine and thymine are pyrimidines. 
E) they allow variation from one nucleotide to another which creates the encoded information.

Question 15

The term 'recombinant organism' refers to

Accepted Answer

A) an organism that has genes passed down from the parent cell to the daughter cells during binary fission. 
B) genetically engineered cells, but not those that have new genes as a result of horizontal gene transfer. 
C) an organism that expresses proteins coded for by genes that originated in a different organism. 
D) an organism that has recombined its genes.

Question 16

If the wild type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATA ETH EBI GRA T?

Accepted Answer

A) Missense 
B) Nonsense 
C) Insertion 
D) Deletion 
E) Silent

Question 17

You have taken E. coli strain A which has its own plasmids, and mixed it with E. coli B strain without plasmids. E. coli B cells now have plasmids but, in addition, they also carry some genes from E. coli A strain. What has happened is

Accepted Answer

A)  the E. coli B cells have become mutants of the original culture. 
B)  vertical transmission of DNA has occurred. 
C)  an example of transformation. 
D)  the cells of E. coli A were Hfr cells.

Question 18

Full induction of the lactose operon requires

Accepted Answer

A) lactose present. 
B) lactose and glucose present. 
C) lactose present without glucose. 
D) lactose and arabinose present.

Question 19

Erythromcycin, a macrolide, inhibits protein synthesis

Accepted Answer

A) by interfering with both the initiation and elongation stages of translation. 
B) by binding to the tRNA preventing peptide bond formation between amino acids. 
C) by preventing the formation of the initiation complex. 
D) by binding to the ribosome, preventing translocation due to interference with the attachment of mRNA.

Question 20

Semiconservative replication refers to

Accepted Answer

A) each base bonding at the 1'position of the sugar. 
B) a purine always bonding to a pyrimidine. 
C) one helix strand that runs from the 5'to 3'direction and the other strand that runs from the 3'to 5'direction. 
D) an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.

Exam 9: Microbial Genetics