Introduction to Microbiology

Question 1

What is microbiology?

Answer 1

Science that studies microorganisms.

Question 2

What is a microorganism?

Answer 2

Living organisms that are too small to be seen with the naked eye.

Question 3

What is bacteriology?

Answer 3

The study of bacteria.

Question 4

What is mycology?

Answer 4

The study of fungi.

Question 5

What is protozoology?

Answer 5

The study of protozoans.

Question 6

What is algae biology?

Answer 6

The study of algae.

Question 7

What is virology?

Answer 7

The study of viruses.

Question 8

What is parasitology?

Answer 8

The study of parasites.

Question 9

What are the normal flora?

Answer 9

Collection of microorganisms that colonize the body without causing any disease.

Question 10

What are the two types of normal flora?

Answer 10

Resident and transient flora.

Question 11

What is the difference between resident and transient flora?

Answer 11

Resident is relatively fixed or permanent, regrow if distributed, located in eye, nose, throat, mouth, skin, etc. Transient is derived from local environment, stay for days, weeks, or months, then disappear depending on host conditions.

Question 12

What are the two factors that determine whether a person will contract a disease?

Answer 12

Disease causing properties of microorganisms and the body’s defence or the host’s resistance.

Question 13

What measurements do we primarily deal in for microorganisms?

Answer 13

Micrometers and nanometers.

Question 14

What are the two sets of lenses in a microscope?

Answer 14

Ocular (eyepiece) and objective, visible light is the source of illumination.

Question 15

What magnification is the ocular lens?

Answer 15

10 X.

Question 16

What magnification is the objective lens?

Answer 16

There is multiple, 4 X (scan), 10 X (low power), 40 X, 43 X, 45 X (high dry power), and 100 X (oil immersion or high power.

Question 17

What is the total magnification calculated?

Answer 17

Multiplying magnification of ocular lens with magnification of objective lens.

Question 18

What are stains?

Answer 18

Salts composed of a positively charged ion and a negatively charged ion, the colour of basic dyes is in the cation, while the colour of acidic dyes is in the anion.

Question 19

What is an example of how staining works?

Answer 19

Bacteria are slightly negatively charged, so basic dye will stain bacterial cells, while acidic dye will stain the background of bacterial smear (negative staining).

Question 20

What is a gram stain?

Answer 20

A procedure to to divide bacteria into two large groups, gram-positive and gram-negative.

Question 21

How does gram staining work?

Answer 21

Heat-fixed smear -> basic dye (crystal violet) applied as primary stain shows purple -> washed off -> iodine added -> alcohol (decolorization) -> rinsed off -> basic dye used as counterstain -> washed off -> blotted dry -> gram positive shows purple and gram negative shows pink.

Question 22

What is an acid-fast stain?

Answer 22

Binds strongly to bacteria that have a waxy material in their cell walls.

Question 23

What are acid-fast stains and gram stains?

Answer 23

Differential stains.

Question 24

What is an example of a special stain?

Answer 24

Negative staining for capsules.

Question 25

What is negative staining for capsules?

Answer 25

This procedure stains the cell capsules as they are hard to stain, this creates a halo effect around the cells to show the capsules on a dark background, the capsule determines virulence.

Question 26

What is an endospore?

Answer 26

Special, resistant, dormant structures formed within certain bacterial cells, protect bacteria from adverse environmental conditions.

Question 27

What is spore staining?

Answer 27

Stains endospores.

Question 28

What is a TEM?

Answer 28

Transmission electron microscope.

Question 29

What is a SEM?

Answer 29

Scanning electron microscope.

Question 30

How is a TEM different from a SEM?

Answer 30

A TEM is for looking at thin cross sectioned slices of specimen while a SEM is for 3D views of intact organisms to see the whole thing.

Question 31

What is a prokaryotic cell?

Answer 31

Primitive cells, such as bacteria, lack membrane-bound nucleus or organelles.

Question 32

What is a eukaryotic cell?

Answer 32

Advanced cells, such as plant and animal cells, have membrane-bound nucleus and organelles, grow by mitosis, and reproduce by meiosis.

Question 33

What are the basic cell shapes?

Answer 33

Spherical (coccus), rod-shaped (bacillus), and twisted (spiral).

Question 34

What are the cocci cell arrangements?

Answer 34

Diplococci (in pairs), streptococci (chainlike paterns), and staphylococci (grape like clusters).

Question 35

What are the bacilli cell arrangements?

Answer 35

Diplobacilli (in pairs), streptobacilli (in chains), coccobacilli (like cocci) but mostly are single rods.

Question 36

What are the spiral cell arrangements?

Answer 36

One or more twists, never straight, including vibrio (like comma), spirillum (like corkscrew), with flagella, and spirochete (helical and flexible) without flagella.

Question 37

What is a glycocalyx?

Answer 37

A structure external to the cell wall, gelatinous polysaccharide or polypeptide covering, can be capsule or slime layer.

Question 38

What is a capsule?

Answer 38

Firmly attached to the cell wall, determined by negative staining and contribute to bacterial virulence.

Question 39

What is a slime layer?

Answer 39

Loosely attached to the cell wall with adhesive property.

Question 40

What is the flagella?

Answer 40

Long threadlike appendages that propel bacteria.

Question 41

What is the plasma membrane?

Answer 41

Encloses the cytoplasm, is a phospholipid bilayer with proteins embedded, shows selective permeability, carries enzymes for metabolic activities, and can be destroyed by alcohols.

Question 42

What is the cytoplasm?

Answer 42

Fluid component inside the plasma membrane.

Question 43

What is the nuclear area or nucleoid region?

Answer 43

Contains DNA of the bacterial chromosome (single, long, circular, and double stranded).

Question 44

What are plasmids?

Answer 44

Extrachromosomal genetic elements (small, circular, and double stranded DNA).