20 Top BACTERIA Questions and Answers

1. All the bacteria fix nitrogen except
A. Rhizobium
B. E.coli
C. Azotobacter
D. cyanobacteria

2. Differential staining of bacteria on Gram staining is due to
A. difference in the cell wall layer components of Gram positive and Gram negative bacteria
B. difference in the cell structure of Gram positive and Gram negative bacteria
C. difference in the mode of nutrition of Gram positive and Gram negative bacteria
D. none of the above

3. The iodine used in Gram staining serves as a
A. chelator
B. catalyst
C. mordant
D. cofactor

4. Which among the following is called as filamentous bacteria
A. Mycoplasmas
B. Spirochetes
C. Actinomycetes
D. Vibrios

5. Which of the following group of bacteria is considered as a link between bacteria and virus
A. Mycoplasmas
B. Spirochaetes
C. Actinomycetes
D. Vibrios

6. Cork-screw shaped forms of bacteria are
A. bacilli
B. stalked bacteria
C. spirochaetes
D. actinomycetes

7. The ability of bacteria to change their morphological form frequently is termed as
A. lysogeny
B. pleomorphism
C. alteromorphism
D. none of these

8. Bacterial cell wall is made up of

A. chitin
B. cellulose
C. dextran
D. peptidoglycan

9. Bacterial flagella is made up of
A. microtubules
B. tubulin
C. flagellin
D. spinin

10. Surface appendage of bacteria meant for cell-cell attachment during conjugation is
A. pili
B. flagella
C. spinae
D. cilia

BACTERIA Questions and Answers ::

11. Spinae is rigid tubular appendages in
A. Gram positive bacteria
B. Gram negative bacteria
C. both a and b
D. actinomycetes

12. The region where bacterial genome resides is termed as
A. nucleus
B. cytoplasm
C. nucleoid
D. ribosome free region

13. Bacterial chromosome is
A. single stranded and circular
B. double stranded and circular
C. single stranded and linear
D. double stranded and linear

14. Extra chromosomal, circular, double stranded, self-replicating DNA molecule in bacteria is called
A. cosmid
B. plasmid
C. phagemid
D. phasmid

15. Membraneous infolding in bacteria that initiate DNA replication is
A. mesosomes
B. carboxysome
C. magnetosome
D. nulcleosome

Answers

1-b
2-a
3-c
4-c
5-a
6-c
7-b
8-d
9-c
10-a
11-a
12-c
13-b
14-b
15-a

16. Which of the following is/are not a gram-positive bacteria?

A. Streptococci
B. Pseudomonas
C. Mycobacteria
D. None of these

ANSWER: B

17. Gram-positive bacteria, responsible for food poisoning, is/are

A. Mycoplasmas
B. Pseudomonas
C. Clostridia
D. all of these

ANSWER: C

18. The gram-positive bacteria lack __________ structure/component?

A. outer membrane
B. murein
C. teichoic acid
D. plasma membrane

ANSWER: A

19. Which of the following gram-positive bacteria causes pharyngitis (sore throat)?

A. Neisseria
B. Streptococcus
C. Staphylococcus
D. Mycobacterium

ANSWER: B

20. Which of the following gram-negative bacteria is/are not aerobic?

A. Pseudomonas
B. Neisseria
C. Escherichia
D. None of these

ANSWER: C