TOP 100+ Bacteria MCQ and Answers with FREE PDF

Bacteria MCQ and Answers: How well do you know about bacteria? Take this set of MCQs on the topic of bacteria and try to figure out what’s right or wrong. This MCQs & answers sheet on Bacteriology and Microbiology was designed for students preparing for NEET (National Eligibility Entrance Test). The questions were based on the Bacteria chapter from NCERT science textbook class XI by the CBSE board.

Bacteria MCQ and Answers

1. What is sarcinae?

a) Cocci group of bacteria

b) Chainlike group of bacteria

c) Cubelike group of bacteria

d) Grapelike cluster of bacteria

Answer: Cubelike group of bacteria

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

Answer: difference in the cell wall layer components of Gram positive and Gram negative bacteria

3. The iodine used in Gram staining serves as a

a) chelator

b) catalyst

c) mordant

d) cofactor

Answer: mordant

4. Which among the following is called filamentous bacteria

a) Mycoplasmas

b) Spirochetes

c) Actinomycetes

d) Vibrios

Answer: Actinomycetes

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

Answer: Mycoplasmas

6. Cork-screw shaped forms of bacteria are

a) bacilli

b) stalked bacteria

c) spirochaetes

d) actinomycetes

Answer: spirochaetes

7. The ability of bacteria to change their morphological form frequently is termed as

a) lysogeny

b) pleomorphism

c) alteromorphism

d) none of these

Answer: pleomorphism

8. Bacterial cell wall is made up of

a) chitin

b) cellulose

c) dextran

d) peptidoglycan

Answer: peptidoglycan

9. Bacterial flagella are made up of

a) microtubules

b) tubulin

c) flagellin

d) spinin

Answer: flagellin

10. Surface appendage of bacteria meant for cell-cell attachment during conjugation is

a) pili

b) flagella

c) spinae

d) cilia

Answer: pili

11. Spinae is rigid tubular appendages in

a) Gram positive bacteria

b) Gram negative bacteria

c) both a and b

d) actinomycetes

Answer: Gram positive bacteria

12. The region where bacterial genome resides is termed as

a) nucleus

b) cytoplasm

c) nucleoid

d) ribosome free region

Answer: nucleoid

13. Bacterial chromosome is

a) single stranded and circular

b) double stranded and circular

c) single stranded and linear

d) double stranded and linear

Answer: double stranded and circular

14. Extra chromosomal, circular, double stranded, self-replicating DNA molecule in bacteria is called

a) cosmid

b) plasmid

c) phagemid

d) phasmid

Answer: plasmid

15. Membraneous infolding in bacteria that initiate DNA replication is

a) mesosomes

b) carboxysome

c) magnetosome

d) nulcleosome

Answer: mesosomes

16. Mark the common feature between eukaryotes and prokaryotes.

a) Shape of DNA

b) Number of chromosomes

c) A prokaryotic cell is similar to a eukaryotic organelle

d) Cell wall

Answer: A prokaryotic cell is similar to a eukaryotic organelle

17. Which of the following gene deduced the evolutionary relationship between the taxonomic


a) 16S rRNA

b) 23S rRNA

c) 5S rRNA

d) 18S rRNA

Answer: 16S rRNA

18. Name the scientist who proposed the phylogenetic tree for living things.

a) Carlo Urbani

b) Louis Pasteur

c) Robert Koch

d) Carl Woese

Answer: Carl Woese

19. The largest bacteria which can be visible by the unaided eye is_______

a) Thiomargarita namibiensis

b) Lactobacillus

c) Mycoplasma

d) Pseudomonas

Answer: Thiomargarita namibiensis

20. Which of the following is NOT the basic shape of the bacteria?

a) Rod shape

b) Square shape

c) Comma shape

d) Spiral shape

Answer: Square shape

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