医学微生物英语试题

Part 1 Single Best Choice Questions (40 1 point=40 pts)

Instruction: (1) Mark the letter that corresponds to the right answer in the formatted ANSWER SHEET with 2B PENCIL. Since the marks are read by computer, answers in this question sheet will not be collected. (2) For one question, only one letter is permitted to be darkened, otherwise, it will be recognize as wrong by the computer. (3) Do not forget to mark your student ID number and write in your name.

1. Bacteria that lack cell walls and do not synthesize the precursors of peptidoglycan are called

A. Spirochetes

B. Chlamydiae

C. Mycoplasmas

D. L forms

E. Bacilli

2. Each of the following is a typical property of obligate anaerobe EXCEPT

A. They generate energy by using the cytochrome system

B. They grow best in the absence of air

C. They lack superoxide dismutase

D. They lack catalase

E. Tetanus is caused by a typical obligate anaerobe

3. . Which one of the following agents lacks nucleic acid?

A. Bacteria

B. Viruses

C. Viroids

D. Prions

E. Protozoa

4. Which one of the following most correctly describes vaccines containing live, attenuated (weaken) pathogens?

A. Pathogen does not multiply in human hosts

B. They provide extended, sometimes life-long immunity

C. There is no possibility for reversion to pathogenic form

D. They provide little cell-mediated immunity

E. They are administered by injection

5. Each of the following statements concerning the killing of bacteria is correct EXCEPT

A. A 70% solution of ethanol kills more effectively than absolute (100%) ethanol

B. An autoclave uses steam under pressure to reach the killing temperature of 121 oC

C. The pasteurization of milk kills pathogens but allows many organisms and spores to survive

D. Iodine kills by causing the formation of thymine dimers in the bacterial DNA

E. Ultraviolet is widely used to disinfect the air of a room

6. A patient presents with severe colitis associated with an overgrowth of Clostridium difficile (艰难梭菌) in the lower bowel. The most likely cause of this condition is

A. botulinum food poisoning

B. a stomach ulcer

C. a compromised immune system

D. abtibiotic therapy

E. mechanical blockage of the large intestine

7. The growth rate of bacteria during the exponential phase of growth is

A. Zero

B. Increasing

C. Constant

D. Decreasing

E. Negative

8. A principal criterion for the diagnosis of meningococcal meningitis is observation of bacteria in a sample of

A. urine

B. spinal fluid

C. saliva

D. throat swab

E. sputum

9. Each of the following statements concerning peptidoglycan is correct EXCEPT

A. It has a backbone composed of alternating units of muramic acid and acetylglucosamine

B. Cross-links between the tetrapeptides involve D-alanine

C. It is thinner in gram-positive than in gram-negative cells

D. It can be degraded by lysozyme

E. It can be degraded by penicillin

10. Each of the following is a typical property of obligate anaerobe EXCEPT

A. They generate energy by using the cytochrome system

B. They grow best in the absence of air

C. They lack superoxide dismutase

D. They lack catalase

E. Tetanus is caused by a typical obligate anaerobe

11. The effects of antibody on bacteria include each of the following EXCEPT

A. Lysis of gram-negative bacteria in conjunction with complement

B. Augmentation of phagocytosis

C. Increase in the frequency of lysogeny

D. Inhibition of adherence of bacteria to mucosal surfaces

E. Neutralize exotoxins

12. Each of the following statements concerning exotoxins is correct EXCEPT

A. Exotoxins are polypeptides

B. Exotoxins are more easily inactivated by heat than are endotoxins

C. Exotoxins are less toxic than the same amount of endotoxins

D. Exotoxins can be converted to toxoids

E. Exotoxins are usually composed of two subunits including binding subunit and active subunit

13. Each of the following statements concerning the killing of bacteria is correct EXCEPT

A. A 70% solution of ethanol kills more effectively than absolute (100%) ethanol

B. An autoclave uses steam under pressure to reach the killing temperature of 121 oC

C. The pasteurization of milk kills pathogens but allows many organisms and spores to survive

D. Iodine kills by causing the formation of thymine dimers in the bacterial DNA

E. Ultraviolet is widely used to disinfect the air of a room

14. Each of the following statements concerning the normal flora is correct EXCEPT

A. The normal flora of the colon consists predominantly of anaerobic bacteria

B. The presence of the normal flora prevents certain pathogens from colonizing the upper respiratory tract

C. Fungi, eg, yeasts, are not members of the normal flora

D. Organisms of the normal flora are permanent residents of the body surfaces

E. Normal flora may occasionally cause diseases

15. The growth rate of bacteria during the exponential phase of growth is

A. Zero

B. Increasing

C. Constant

D. Decreasing

E. Nagtive

16. Which of the following statements regarding virus character is true? A．Viruses replicate by binary fission

B．All RNA viruses are spherical in shape

C．Helical nucleocapsids are found with single-stranded DNA viruses D．Some viruses with DNA genomes contain a primitive nucleus.

E．Viral surface proteins protect the viral genome from nucleases

17. A 40-year-old woman is diagnosed with cervical cancer. This cancer is common worldwide and has a sexually transmitted viral etiology. The causative agents of human cervical cancer include:

A. HCV

B. HBV

C. HIV

D. HPV, low-risk types 6 and 16.

E. HPV, high-risk types 16 and 18.

18. Which one of the following viruses possesses an RNA genome that is infectious when purified?

A. Influenza virus

B. Poliovirus

C. Papillomavirus

D. Measles virus

E. Rotavirus

19. Which of the following descriptions about endocytosis in viral entry is true:

A. host plasma membrane surrounds whole virion and forms a vesicle

B. host plasma membrane surrounds only viral protein coat and forms a vesicle

C. host plasma membrane surrounds only viral nucleic acid and forms a vesicle

D. viral spikes fuse with host plasma membrane

E. host plasma membrane surrounds only viral spikes and forms a vesicle

20. The type-specific antigen (A, B, or C) of influenza viruses is found on which viral constituent?

A. Hemagglutinin

B. Neuraminidase

C. Nucleocapsid

D. Polymerase complex

E. Major nonstructural protein

21. Which of the following can be used to quantitate the infectious titer of viruses?

A. Electron microscopy

B. Polymerase chain reaction

C. Plaque assay

D. Enzyme immunoassay

E. Hemagglutination 22. A middle-aged man complained of acute onset of fever, nausea, and pain in the right upper abdominal quadrant. There was jaundice, and dark urine had been observed several days earlier. A laboratory test was positive for HAV IgM antibody. The physician can tell the patient that

A. He probably acquired the infection from a recent blood transfusion

B. He does not need to worry about to develop chronic hepatitis.

C. There is less possibility to transmit the infection to family members by person-to-person spread for up to 2 weeks.

D. He will be resistant to infection with hepatitis B.

E. He will be at high risk of developing hepatocellular carcinoma

23. The presence in neurons of eosinophilic cytoplasmic inclusion bodies, called Negri bodies, is characteristic of which of the following central nervous system infections?

A. Herpes virus infection

B. Rabies

C. Subacute sclerosing panencephalitis (SSPE)

D. New variant Creutzfeldt-Jakob disease

E. Postvaccinal encephalitis

24. When HSV is not active in the body, what happens to it?

A. It lies dormant in the liver.

B. It lies dormant inside nerve cells.

C. It is eliminated from the body.

D. It lies dormant in the lung.

E. None of the above.

25. Ebola virus is highly virulent to humans. The following facts are correct except:

A. Studying live virus needs BSL-2 to BSL-4 ( biosafety laboratory).

B. The virus may be transmitted by direct contact of body fluid among humans.

C. The virus may be transmitted from bat to humans.

D. The virus can cause hemorrhage and high fever.

E. The virus is filament shaped.

26. Killing of liver cells infected with HBV is primarily caused by:

A. Shut-off of cellular protein synthesis.

B. Degradation (降解) of cellular mRNA.

C. Attack by cytotoxic T lymphocytes directed against HBV antigens.

D. Cellular genome rearrangement and deletion induced by HBV infection.

E. None of the above.

27. Infectious BSE (bovine spongiform encephalitis) agent can be detected in amyloid plaques (淀粉样蛋白斑) in infected brains of cows. Which of the following descriptions regarding its nucleic acid types is correct?

A. Negative-sense, single-stranded RNA.

B. No detectable nucleic acid.

C. DNA copy of RNA genome, integrated in mitochondrial DNA.

D. Single-stranded, circular DNA.

E. Small interfering RNA, smallest known infectious RNA.

28. The “asymptomatic period” following the initial acute HIV-1 infection is characterized by:

A. High levels of HIV replication in lymphoid tissue.

B. High levels of HIV replication in peripheral T cells.

C. Inability of the immune system to respond to antigen stimulation.

D. Absence of detectable HIV genomes or mRNA in peripheral T cells.

E. High levels of free virus in the blood.

29. The following viruses are highly associated with carcinogenesis, except:

A. HTLV

B. HBV

C. HCV

D. HPV

E. HEV

30. Both Burkitt lymphoma and infectious mononucleosis are caused by what virus?

A. Cytomegalovirus

B. Epstein-Barr virus

C. Varicella-zoster virus

D. Herpes simplex-1

E. Adenovirus

31. Which of the following components are found in the cell walls of

gram-positive bacteria but not gram-negative bacteria?

A. Peptidoglycan

B. Lipopolysaccharide

C. Lipoproteins

D. Teichoic acid

E. Outer membrane

32. Which one of the following statements concerning plasmids is true?

A. All plasmids can be transferred between bacteria by conjugation

B. Much of the information coded in the plasmid is essential to the survival of the bacterial cell

C. Resistance plasmids carry genes for antibiotic resistance

D. Resistance plasmids cannot be transferred to other bacterial cells

E. Plasmids lack an origin of replication

33. A 48-old woman presented at the emergency room complaining of urinary urgency (尿急) and waist pain. Microscopic examination of a urine sample revealed ram-negative rods. Prior to initiation of antibiotics therapy, she abruptly developed fever and chills. Hypotension (low blood pressure) and hyperventilation rapidly followed. These observations suggest that the patient is responding to the release of bacterial

A. collagenase

B. exotoxin

C. hyaluronidase

D. lipopolysaccharide

E. peptidoglycan

34. Most microorganisms pathogenic for humans grow best in the laboratory when cultures are incubated at A. 15 – 20 oC

B. 20 – 30 oC

C. 30 – 37 oC

D. 38 – 50 oC

E. 50 – 55 oC

35. The form of genetic exchange in which donor DNA is introduced to the recipient by a bacterial virus is

A. Transformation

B. Conjugation

C. Transduction

D. Transfection （转染）

E. Mutation

36. Each of the following statements concerning endotoxins is correct EXCEPT

A. Endotoxins are more stable on heating than exotoxins

B. Endotoxins bind to specific cell receptors, whereas exotoxins do not

C. Endotoxins are part of the bacterial cell wall, whereas exotoxins are not

D. Endotoxins are less toxic than exotoxins of the same weight amount

E. The toxic component of endotoxins is lipid A

37. Which of the following is appropriate to determine the etiologic diagnosis of infection?

A. Culture and identification of the agent

B. PCR detection of pathogen-specific genes in patients’ specimens

C. Demonstration of a meaningful antibody or cell-mediated immune response

to an infectious agent

D. Morphologic identification of the agent in stains of specimens or sections of tissues by light or electron microscopy

E. All of the above

38. The growth rate of bacteria during the exponential phase of growth is

A. Zero

B. Increasing

C. Constant

D. Decreasing

E. Negative

39. Which of the following statements is true?

A. Mycobacterium tuberculosis produces a lipopolysaccharide.

B. Rickettsia and Shigella sonnei are both members of the Enterobacteriacae..

C. Enterobacteriaceae do not cause opportunistic infections.

D. Helicobacter pylori can cause stomach ulcers

E. Pathogens never carry out autolysis (self digestion) this is one of the reasons they are so virulent.

40. Clostridium tetani grows in a/an _____ environment.

A. acidic

B. anaerobic

C. high oxygen

D. aerobic

E. high osmotic

Part II Blank Filling (20 blanks ?1 point=20 pts )

Instruction: Write the answers in the answer sheets. You do not need to rewrite the questions in the answer sheets, just write the answer after the question number.

1.Basic structure of virus includes ________, Polymerases and ________; Special structure of virus includes _________ and _________.

2. In a bacterium cell, there are several genetic materials, including _________,_________,and ________.

3. Some bacteria can be transmitted through sexual route. They are ________, ________, and __________.

4.The general steps in viral replication cycles are: (1) ________, ________, and ________. (2) ________. (3) assembly and ________

5. Please list 5 viral pathogens that may cause sexually-transmitted infections (STI) __ ____, ____ ____, ____ ____, ________, and ________ .

Part III Answer the following questions briefly (5?5 point=25 pts)

Instruction: (1) Write the answers in the answer sheets. You do not need to rewrite the questions in the answer sheets, just write the answer after the question number. (2) A concise answer to exactly meet the question is preferable, for example, give a list of the key points. You don’t need to write an essay.

1.Staphylociccus aureus produces various virulent factors including enzymes and toxins that cause injuries and diseases in human beings.

Please write at least five of these virulent factors.

2.Tetanus is caused by clostridium tetani when an open deep injury happens.if there is someone with an injury, what should we do to prevent

tetanus?

3.Please analyze the possible mechanisms for influenza virus antigenic shift and the outcomes.

4.Describe the types of hepatitis viruses, transmission routes and the relation with HCC.

5.Depict the common infection characteristics for herpes viruses by examples, please.

Part ⅣCase Questions (7pts+8pts=15pts)

Instruction: (1) Write the answers in the answer sheets. You do not need to rewrite the questions in the answer sheets, just write the answer after the question number. (2) A concise answer to exactly meet the question is preferable.

1.Please describe the differences of attenuated vaccines and killed vaccines in terms of the inoculation methods, inoculation times, protective period, antibody

types, and storage. (7pts)

2.Please explain the clinical significance of HBV serologic markes in patients with hepatitis.(8pts)