Microbiology

Chapter 4

1. What organisms are thought to be the first cells to appear on earth?

A) Bacteria

B) Insects

C) Archae

D) Reptiles

E) Fungi

2. Which component is not found in the cytoplasm of the majority of procaryotes?

A) Capsule

B) Ribosomes

C) Granules

D) DNA

E) Nucleoid

3. What term refers to the fine, hairlike bristles that aid in adhesion in procaryotic organisms?

A) Flagella

B) Pili

C) Ribosomes

D) Fimbriae

E) Glycocalyx

4. In a peritrichous arrangement of flagella, how are the flagella distributed over the organism?

A) Multiple flagella attached to one end of the cell

B) Multiple flagella attached to both ends of the cell

C) A single flagellum at both ends of the cell

D) A single flagellum at one end of the cell

E) Multiple flagella randomly dispersed over the cell surface

5. Why is the flagellum effective in guiding bacteria through the environment?

A) The axial filaments act as sensors

B) The system for chemical detection is linked to the mechanisms that drive the flagellum

C) The flagellum moves via the expenditure of ATP

D) Biofilms aid in the detection of chemicals for the flagellum

E) Flagella themselves act as environmental sensors

6. In motile bacteria the presence of attractant molecules causes an increase in what?

A) The number of flagella

B) The number of tumbles

C) The length of runs

D) The length of flagella

E) The length of tumbles

7. What type of organisms possesses axial filaments?

A) Gram positives

B) Cocci

C) Bacilli

D) Spirochetes

E) Fungi

8. What type of appendage may be responsible for the formation of biofilms?

A) Pili

B) Fimbria

C) Flagella

D) Axial filaments

E) Glycocalyx

9. Pili, elongated tubular structures composed of pilin, are only found on what type of organisms?

A) Spirochetes

B) Fungi

C) Encapsulated organisms

D) Gram negatives

E) Gram positives

10.

Which of the following is not an example of a biofilm?

A) A single bacterial cell growing on an agar surface

B) Human normal flora

C) Toilet bowl scum

D) Organisms that colonize indwelling medical devices

E) Dental plaque

11. Why are encapsulated bacteria generally more pathogenic than unencapsulated strains?

A) Because the capsule stimulates a potent immune response in the host

B) Because phagocytes do not recognize a capsule as foreign

C) Because the capsule helps prevent phagocyte attachment to the organism

D) Because the capsule causes the phagocyte to mutate

E) Because the capsule allows the organism to hide in the body of the host

12. Which of the following is incorrect regarding the bacterial cell wall?

A) It is a target of certain antibiotics

B) It determines the shape of a bacterium

C) It prevents a bacterium from bursting due to changes in osmotic pressure

D) Its composition varies among the major bacterial groups

E) It is composed of a repeating framework of lipids

13. What is the key differentiating step in the Gram stain procedure?

A) Application of the primary stain

B) Application of the mordant

C) The decolorization step

D) Application of the counterstain

E) Rinsing the smear with water

14. The outermost layer of the outer membrane is composed of what?

A) Teichoic acid

B) Glycerol polymers

C) Lipopolysaccharide

D) Porins

E) Periplasm

15. Which statement describes why Gram negative organisms are more sensitive to lysis than Gram positive organisms?

A) They have an outer membrane

B) Porins form holes in the envelope

C) Gram negatives have a well-developed periplasmic space

D) Gram negatives have endotoxin

E) The peptidoglycan layer of the cell while is quite thin

16. The acid fast stain is used to identify organisms containing what chemical in their cell walls?

A) Lipoteichoic acids

B) Lipopolysaccharide

C) Porin proteins

D) Peptidoglycan

E) Mycolic acid

17. What is not a function of the bacterial cytoplasmic membrane?

A) Storage of nutrient reserves

B) Regulation of transport

C) Secretion of various products

D) Synthesis of structural macromolecules

E) Respiration and ATP synthesis

18. How many chromosomes do bacteria possess?

A) Zero

B) One

C) Six

D) Ten

E) 23 pairs

19.

Which of the following is incorrect regarding plasmids?

A) They are extra-chromosomal

B) They can become integrated into the bacterial chromosome

C) They can confer protective traits

D) They are essential for bacterial growth and survival

E) They are important in genetic engineering techniques

20. Under what conditions can endospores form?

A) When carbon and nitrogen sources become depleted

B) When the cell forms inclusion bodies

C) When the cell reproduces

D) When the cell germinates

E) When the vegetative cells are dormant

21. What is not one of the three general shapes possessed by bacteria?

A) Rods

B) Cocci

C) Bacilli

D) Curved forms

E) Pleomorphic

22. The style of bacterial grouping, or arrangement, is based on what factor?

A) The shape of the organisms in the group

B) The number of planes in which the bacteria divide

C) The size of the individual cells in the group

D) The number of flagella present

E) The speed at which the organisms in the group divide

23. Identification of bacteria requires a study of all but which of the following?

A) Microscopic and macroscopic morphology

B) Bacterial physiology

C) Quantitative analysis

D) Serological analysis

E) Genetic and molecular analysis

24. Current strategies for determining evolutionary relatedness between organisms rely upon what?

A) rRNA sequence analysis

B) Macroscopic morphology

C) Rigid classification systems

D) Studies of ecological habitats

E) Recognition by the immune system

25. What type of bacteria naturally lacks a cell wall?

A) Photosynthetic bacteria

B) Those that are obligate intracellular parasites

C) The appendaged bacteria

D) The Mycoplasmas

E) The Archae