微生物期末英文习题答案

一、CHOICE QUESTIONS：（20 Cent）

1. Catabolism is a form of metabolism in which ___ molecules are converted into ___

molecules.

a. large, small c. amino acid, protein

b. small, large d. food, storage

a. sterilizes

b. inhibits microorganisms

c. is toxic to human cells

d. destroys microorganisms

3. Environmental factors such as temperature and pH exert their effect on the ___ of

microbial cells.

a. membranes c. enzymes

b. DNA d. cell wall

4. In general , fungi derive nutrients through

a. photosynthesis c. digesting organic substrates

b. engulfing bacteria d. parasitism

5. Both flagella and cilia are found primarily in__

a. algae c. fungi

b. protozoa d. both b and c

6. Which of the following is not found in all bacterial cells ?

a. cell membrane c. ribosomes

b. a nucleoid d. capsule

7. Pili are tubular shafts in ___bacteria that serve as a means of ___.

a. gram-positive, genetic exchange

b. gram-positive, attachment

c. gram-negative, genetic exchange

d. gram-negative, protection

a. transport c. support

b. motility d. adhesion

.

a. micrococcus c. tetrad

b. diplococcus d.sarcina

10. Genetic analysis of bacteria would include

a. fermentation testing

b. ability to digest complex nutrients

c. presence of oxidase

d. G+C content

11. In general, if two haploid cells fuse , __will result .

a. a germ cell c. mitosis

b. a diploid zygote d. meiosis

12. What is embedded in rough endoplasmic reticulum ?

a. ribosomes c. chromatin

b. Golgi apparatus d. vesicles

a. photosynthesis c. digesting organic substrates

b. engulfing bacteria d. parasitism

14. An organism that can synthesize all its required organic components from CO2

using energy from the sun is a a. photoautotroph c. chemoautotroph

b. photoheterotroph d. chemoheterotroph

a. pH c. salt

b. temperature d. pressure

16. Catabolism is a form of metabolism in which ___ molecules are converted into

___ molecules.

a. large, small c. amino acid, protein

b. small, large d. food, storage

17. An enzyme

a. becomes part of the final products

b. is nonspecific for substrate

c. is consumed by the reaction

d. is heat and pH labile

18. Many coenzymes are

a. metals c. proteins

b. vitamins d. substrates

a. 100℃ and 4 psi c. 131℃ and 9 psi

b. 121℃ and 15 psi d. 115℃ and 3 psi

a. UV radiation c. beta propiolactone

b. exposure d. filtration

二、Fill a vacancy：（15 Cents）

2. A spore , and a zygospore is

spore .

3. An organic nutrient essential to an organism’s metabolism that cannot be

5. Superoxide ion is toxic to strict anaerobes because they lack 6. During the phase, the rate of new cells being added to the

population has slowed down.

8. Microorganisms have two fundamentally different and and are distributed among several kingdoms or domains.9. developed the techniques required to grow bacteria on solid media and to isolate pure cultures of pathogens.

10.Phototrophs capture radiant energy from the Chemoorganotrophs oxidize to liberate energy, while chemolithotrophs employ

?

spore .

3. An organic nutrient essential to an organism’s metabolism that cannot be

6. During the phase, the rate of new cells being added to the

population has slowed down.

7. Microorganisms have two fundamentally different and and are distributed among several kingdoms or domains.

四、CONCEPT QUESTIONS(55 Cents)

1. Describe Koch’s postulates. why are they important?(10 Cents)

Koch’s postulates and can be summarized as follows:

1. The microorganism must be present in every case of the disease but absent from healthy organisms.

2. The suspected microorganism must be isolated and grown in a pure culture.

3. The same disease must result when the isolated microorganism is inoculated into a healthy host.

4. The same microorganism must be isolated again from the diseased host.

The first direct demonstration of the role of bacteria in causing disease

Koch’s proof that Bacillus anthracis caused anthrax was independently confirmed by Pasteur and his coworkers. They discovered that after burial of dead animals, anthrax spores survived and were brought to the surface by earthworms. Healthy animals then ingested the spores and became ill.

2. Give a simple comparison of transport systems in graph? (10 Cents)

3. Describe how conditions influenced the effectiveness of antimicrobial agent activity? (10 Cents)

Destruction of microorganisms and inhibition of microbial growth are not simple matters because the efficiency of an antimicrobial agent (an agent that kills microorganisms or inhibits their growth) is affected by at least six factors.

(1). Population size. Because an equal fraction of a microbial population is killed during each interval, a larger population requires a longer time to die than a smaller one.

(2). Population composition. The effectiveness of an agent varies greatly with the nature of the organisms being treated because microorganisms differ markedly in suscepti …… 此处隐藏：5699字，全部文档内容请下载后查看。喜欢就下载吧 ……