Intro To Microbiology

Question 1

Size of bacterial cell is measured by

Answer 1

Micron

Question 2

The smallest bacterium know is

Answer 2

Serratia marcescens

Question 3

The shpe of staphylococci is

Answer 3

Cocci = spherical

Question 4

The shape of diphtheria bacilli is

Answer 4

Bacilli = cylindrical

Question 5

The shpe of vibrio is

Answer 5

Spiral, one curve

Question 6

The shape of spirochates

Answer 6

Spiral, more than one curve

Question 7

Emxaples of parasitic habitat

Answer 7

Bacteria flora

Pathologenic bacteria

Question 8

TB is stained by

Answer 8

Ziehl neelsen stain

Question 9

What stains did gram use for his experiment

Answer 9

Crystal violet
Gram’s iodine
Acetone-alcohol
Diluted carbol fuchsin

Question 10

Enumerate surface structures of bacterial cell

Answer 10

Capsule
Cell wall
Cytoplasmic membrane

Question 11

Enumerate the internal structures of bacterial cell

Answer 11

Flagella 
Fimbria
Ribosomes
Inclusion body
Nuclear body
Mesosome

Question 12

Define cell wall

Answer 12

The layer that lies outside the cytoplasmic membrane

Question 13

Bacterial cell wall is composed of

Answer 13

Mucopeptide

Question 14

What’re the components of mucopeptide

Answer 14

Backbone of N acetyl glucosamine alternating with N acetyl muramic.
Side chains
Peptidoglycan layer

Question 15

Periplasmic space contains

Answer 15

Hydrolytic enzymes

Pencillinase

Question 16

Enumerate functions of cell wall

Answer 16

Preservation of cell wall’s shape.
Protection against high internal osmotic pressure.
Antigenic characters.
Toxicity.
Staining reaction.
Permeability of the cell.
Target action of antibiotics.
Plays a role in cell division.

Question 17

Characters of cytoplasmic membrane are

Answer 17

Very thin elastic that lies under the cell wall

Question 18

Functions of cytoplasmic membrane

Answer 18

Transport & permeability function.
Biosynthetic function.
Electron transport & oxidative phosphorylation.
Excretion of hydrolytic enzymes & toxins.

Question 19

Mention functions of capsule

Answer 19

Protect cell wall against attack
Protect call against phagocytosis
Antigenic
Determine virulence of an organism

Question 20

Answer the following concerning flagella:

Definition, structure, types

Answer 20

Def.: long thread-like helical filament
Structure: flagellin
Types: monotrichous, amphitrichous, lophotrichous, peritrichous

Question 21

Functions of flagella

Answer 21

Organ of motility

Highly antigenic

Question 22

Why is motility beneficial

Answer 22

It’s used in:
Movement toward optimal nutrients.
Movement toward optimal O2 concentrations.
Choosing suitable location for colonization.
Assist pathogenic bacteria in penetration.

Question 23

How is fimbria different from flagella

Answer 23

Fimbria doesn’t originate from cytoplasm.
Fimbria is thinner & shorter.
Fimbria is more or less straight, while flagella is spiral.
More numerous.
Occur in motile & non-motile bacteria.