C4

Question 1

Cellular microbes

Answer 1

(bacteria, archaea, algae, protozoa, and
fungi)

Question 2

acellular microbes or infectious particles

Answer 2

(viruses, viroids,
and prions)

Question 3

four categories of viruses

Answer 3

*Double-stranded DNA viruses
*Single-stranded RNA viruses
*Single-stranded DNA viruses
*Double-stranded RNA viruses

Question 3

Some viruses cause specific types of cancer

Answer 3

oncogenic viruses or oncoviruses

Question 4

A typical virion consists of a genome of either DNA or
RNA, surrounded by a capsid (protein coat), which is
composed of protein units called

Answer 4

capsomeres

Question 5

Viruses that infect bacteria are known as

Answer 5

bacteriophages
or simply phages

Question 6

There are two categories of bacteriophages

Answer 6

virulent bacteriophages and temperate bacteriophages.

Question 7

always cause what is known as
the lytic cycle, which ends with the destruction of the
bacterial cell

Answer 7

Virulent bacteriophages

Question 8

The five steps in the lytic cycle

Answer 8

attachment,
penetration,
biosynthesis,
assembly,
release.

Question 9

Steps in the multiplication of animal viruses are

Answer 9

• Attachment
• Penetration
• Uncoating
• Biosynthesis
• Assembly

Question 10

Viral infections in which the virus is able to hide from a host’s immune system by entering cells and remaining dormant.

– Herpes viral infections are examples.

Answer 10

Latent virus infections

Question 11

are drugs that are used to treat
viral infections.

Answer 11

Antiviral agents

Question 12

This virus causes acquired immunodeficiency syndrome
(AIDS).

– It is an enveloped, single-stranded RNA virus

Answer 12

Human immunodeficiency virus (HIV)

Question 13

These viruses cause cancer.

Answer 13

Oncogenic viruses or oncoviruses

Question 14

are short, naked fragments of single stranded RNA, which can interfere with the metabolism of plant cells

Answer 14

Viroids

Question 15

are small infectious proteins that
cause fatal neurologic diseases in animals and humans (e.g., Scrapie, bovine spongiform encephalopathy [mad cow disease], and Creutzfeldt–Jacob disease)

Answer 15

Prions

Question 16

Bacteria are divided into three major phenotypic categories

Answer 16

– Those that are Gram-negative and have a cell wall

– Those that are Gram-positive and have a cell wall

– Those that lack a cell wall (Mycoplasma spp.)

Question 17

There are three basic categories of bacteria based on
shape:

Answer 17

– Cocci (round bacteria)

– Bacilli (rod-shaped bacteria

– Curved and spiral-shaped bacteria

Question 18

They are often referred to as rods; they may be short or long, thick or thin, and pointed or with curved or blunt
ends.

– They may occur singly, in pairs (diplobacilli), in chains
(streptobacilli), in long filaments, or branched.

Answer 18

Bacilli

Question 19

Examples of medically important bacilli:

Answer 19

Escherichia, Klebsiella, Proteus,
Pseudomonas, Haemophilus, and Bacillus spp.

Question 20

Extremely short bacilli are called

Answer 20

coccobacilli

Question 21

not a standardized
technique; excess heat will distort bacterial morphology

Answer 21

Heat fixation

Question 22

a standardized
technique; the preferred method

Answer 22

Methanol fixation

Question 23

are often identified using the acid
fast stain

Answer 23

Mycobacterium spp

Question 23

With respect to O2, bacterial isolates can be classified as

Answer 23

– Obligate aerobes
– Microaerophilic aerobes
– Facultative anaerobes
– Aerotolerant anaerobes
– Obligate anaerobe

Question 23

is the red dye that is driven through the bacterial cell wall using heat

Answer 23

Carbol fuchsin

Question 23

Curved and spiral-shaped bacteria example

Answer 23

*Vibrio spp.
*Campylobacter spp.
*Helicobacter spp.

Question 24

Examples of spiral-shaped bacteria

Answer 24

*Treponema spp.
*Borrelia spp

Question 25

are bacteria, but they do not possess all the attributes of
typical bacterial cells.

Answer 25

Rickettsias, chlamydias, and mycoplasmas

Question 26

– They are the smallest of the cellular microbes.

– They lack a cell wall and therefore assume many shapes
(i.e., pleomorphic).

– cause primary atypical pneumonia and genitourinary infections.

– Because they have no cell wall, they are resistant to drugs
like penicillin that attack cell walls.

– They produce tiny “fried egg” colonies on artificial media

Answer 26

Mycoplasmas

Question 27

were discovered in
1977; they are prokaryotic organisms.

Answer 27

Archaea (meaning “ancient”)

Question 28

Organisms with especially demanding nutritional
requirements are said to be

Answer 28

fastidious (“fussy”)

Question 29

Examples of some common pathogenic bacteria

Answer 29

Neisseria meningitidis,
Salmonella typhi,
Shigella spp.,
Vibrio cholerae,
Yersina pestis,
and Treponema pallidum

Question 30

Photosynthesis that does not produce oxygen is called

Answer 30

anoxygenic photosynthesis