Microbiology Final Exam Answers – Flashcards
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Unlock answers| Which of the following methods would be best to sterilize a solution that contains nutrients that are sensitive to heat? |
| Membrane filtration |
| What are some factors related to effectiveness of an antimicrobial treatment? |
| population, environment, time of exposure, microbial characteristics |
| A chemical used to kill most bacteria on living tissue is referred to as a(n)? |
| antiseptic |
| When antiseptics and disinfectants are compared, antiseptics are |
| less toxic. |
| Which of the following inhibits bacterial growth but does not kill bacteria |
| bacteriostatic agent |
| An autoclave is able to sterilize lab equipment because? |
| It uses high temperatures, moisture, and pressure |
| One of the ways Radiation kills cells is by |
Damaging DNA |
| Which of the following is NOT a physical method of microbial control? |
| turbidity |
| The principle of transformation was first demonstrated by which of the following individuals or groups of individuals? |
| Griffith |
| Transformation is transfer of DNA from a donor to a recipient cell.. |
| as naked DNA in solution |
| An enzyme which is produced in response to a substrate is called |
| An inducible enzyme |
| The lac operon is an example of an inducible enzyme system. Thus, for the synthesis of enzymes to occur |
| lactose must bind to the repressor |
| Conjugation differs from reproduction because conjugation |
| transfers DNA horizontally to cells in the same generation |
The figure above shows an example of the growth rate of Escherichia coli on glucose and lactose. Which of the following best describes what is occurring during the lag time period in which all glucose is consumed by the microorganism? |
cAMP increases, the lac operon is transcribed, and the enzymes for lactose metabolism are produced |
Which of the following can be used to make recombinant DNA |
A. Microinjection B. Honolulu cloning technique C. Transformation D. Vectors and electroporation E. All of the above |
| Which of the following reactions are catalyzed by reverse transcriptase |
| mRNA ® cDNA |
| Self-replicating DNA used to transmit a gene from one organism to another is a |
| vector |
| Yeast belong to the Kingdom |
Fungi |
| Why are Archae and Eukaryotes more closely related than Archae and Bacteria |
They evolved from a common ancestor |
| If two organisms have similar rRNA sequences you can conclude all of the following except |
| They can ferment lactose |
| A characteristic consistent in the Kingdom fungi is |
Absorption of dissolved organic matter |
| You begin with one gene that you wish replicated by PCR. After 3 cycles, how many copies of the gene do you have? |
| 8 |
You have isolated a gram-positive, endospore forming bacteria. To which of the following groups does it most likely belong to? |
Low G+C bacteria |
Figure A is the lac operon. Which of the following best describes the relationship of the molecules bound to the operator and promoter if there is no glucose and no lactose present? |
active CAP and lac repressor |
Figure A is the lac operon. Which of the following best describes the relationship of the molecules bound to the operator and promoter if there is glucose and lactose present? |
no molecules will be bound |
| Figure A is the lac operon. Which of the following best describes the relationship of the molecules bound to the operator and promoter if there is no glucose but lactose is present? |
| cAMP high, CAP only |
| Figure B is the trp operon. Which of the following best describes the normal state of this operon? |
| RNA polymerase is consistently transcribing the genes necessary to synthesize tryptophan |
| Figure B is the trp operon. Which of the following best describes this operon if tryptophan is in excess? |
| the trp repressor will be bound to tryptophan and bound to the operator |
| When bound to the DNA, the repressor protein usually prevents attachment of the RNA polymerase to the __________. |
| promoter |
| The value of cDNA in recombinant DNA is |
| it lacks introns |
| The technique of PCR was developed by which of the following individuals or groups of individuals? |
Kary Mullis |
| Which restriction enzyme would cut this strand of DNA: GCATGGATCCCAATGC? |
BamH1, recognition sequence: GATCC |
| Cloning a gene involves all of the following except |
| expression of the vector and the gene in a cell-free environment. |
| Which of the following was first produced commercially using recombinant DNA technology? |
human insulin |
| The __________ describes the specific set of genes an organism possesses. |
| genotype |
| The science dealing with classification is called |
| taxonomy. |
| A classification system based on evolutionary relationships is called a __________ system. |
| phylogenetic |
| The organisms in which of the following are more closely related? |
species |
The percent (G+C) of DNA affects the stability of DNA in |
| higher temperature environments |
| Which of the following is true about lichens? |
B. It is an example of a mutualistic relationship C. It is a combination of an alga (or cyanobacterium) and fungus Both B and C |
| Cyanobacteria are capable of fixing atmospheric N2, and are also examples. |
A. organisms that are gram negative C. organisms that are capable of photosynthesis D. Both A and C
|
Figure above depict a plasmid used for cloning, a(n) _________ allows the plasmid to be self-replicating. Two genes, one coding for antibiotic ampicillin (ampR) and one for the enzyme b-galactosidase (lacZ), serve as _________. |
a. origin of replication, marker genes for selection |
| Fungi |
A. are eukaryotic organisms. D. can reproduce sexually and asexually E. A and D are true
|
| Brown algae are also referred to as |
| Phaeophyta |
| Which group of algae gave rise to modern plants? |
| Chlorophyta |
| A child has type AB blood. Which of the following statements is correct? |
| the child's phenotype is AB |
Figure above describes a method of selecting recombinant bacteria.; The plasmid vector contains a gene (ampR) coding for resistance to the antibiotic ampicillin, and a second gene for the enzyme b-galactosidase (lacZ). In the blue-white screening procedure, a library of bacteria is cultured in a medium called X-gal. X-gal contains two essential components other than those necessary to support normal bacterial growth. Knowing this, why then are some colonies blue and others white? |
a.;;;; bacteria that received the original plasmid containing the intact lacZ gene, the cells will cleave X-gal to produce a blue colored compound, the colonies will be blue |
