CHAPTER 10

Question 1

is the
study of the numerous
interrelationships
between microorganisms
and the world around
them.

Answer 1

Microbial ecology

Question 2

defined as the living to-
gether or close association of two dissimilar organisms

Answer 2

Symbiosis, or a symbiotic relation-
ship,

Question 3

used to describe a symbiotic rela-
tionship in which neither symbiont is affected by the relationship.

Answer 3

neutralism

Question 4

The organisms that live together in such a relationship are referred
to as

Answer 4

symbionts.

Question 5

symbiotic relationship that is beneficial to one sym-
biont and of no consequence

Answer 5

Commensalism

Question 6

is a symbiotic rela-
tionship that is beneficial to both symbionts

Answer 6

Mutualism

Question 7

a symbiotic rela-
tionship that is beneficial to one symbiont (the parasite) and detrimental to the other sym-
biont (the host).

Answer 7

Parasitism

Question 8

these parasites kill their hosts;
then they must either find a new host or die.

Answer 8

DUMB PARASITES

Question 9

parasites that do not cause disease,

Answer 9

smart parasites

Question 10

referred to as “normal

flora”) includes all of the mi-
crobes (bacteria, fungi, proto-
zoa, and viruses) that reside

on and within that person

Answer 10

indigenous microflora
or indigenous microbiota

Question 11

Bacteria and yeasts
that are ingested to
reestablish and stabilize
the microbial balance
within our bodies are

Answer 11

biotherapeutic
agents or probiotics.

Question 12

microbes are
often organized into
complex and persistant
communities of
assorted organisms called

Answer 12

biofilms.

Question 13

The bacteria grow in tiny clusters—called
—that are separated by a network of water
channels.

Answer 13

microcolonies

Question 14

two (or more) microorganisms may “team up” to produce a disease that neither could cause by itself. This is referred to as

Answer 14

synergism or a syner-
gistic relationship.

Question 15

nitrogen-containing animal waste products
(such as urea in urine) are converted by certain bacteria to ammonia by a process known as

Answer 15

ammonification.

Question 16

A symbiont could be a(n):
a. commensal.
b. opportunist.
c. parasite.
d. all of the above

Answer 16

d

Question 17

The greatest number and variety of indigenous
microflora of the human body live in or on the:
a. colon.
b. genitourinary tract.
c. mouth.
d. skin.

Answer 17

a

Question 18

3. Escherichia coli living in the human colon can be considered to be a(n):

a. endosymbiont.
b. opportunist.
c. symbiont in a mutualistic relationship.
d. all of the above

Answer 18

d

Question 19

Which of the following sites of the human body
does not have indigenous microflora?
a. bloodstream
b. colon
c. distal urethra
d. vagina

Answer 19

a

Question 20

Which of the following would be present in highest
numbers in the indigenous microflora of the human
mouth?
a. -hemolytic streptococci
b. -hemolytic streptococci
c. Candida albicans
d. Staphylococcus aureus

Answer 20

a

Question 21

Which of the following would be present in highest numbers in the indigenous microflora of the skin?
a. C. albicans
b. coagulase-negative staphylococci
c. Enterococcus spp.
d. E. coli

Answer 21

b

Question 22

7. The indigenous microflora of the external ear canal is most like the indigenous microflora of the:
   a. colon.
   b. mouth.
   c. skin.
   d. distal urethra.

Answer 22

c

Question 23

8. Which of the following are least likely to play a role in the nitrogen cycle?
   a. indigenous microflora
   b. nitrifying and denitrifying bacteria
   c. nitrogen-fixing bacteria
   d. bacteria living in the root nodules of legumes

Answer 23

a

Question 24

9. Microorganisms are used in which of the following
   industries?
   a. antibiotic
   b. chemical
   c. food, beer, and wine
   d. all of the above

Answer 24

d

Question 25

The term that best describes a symbiotic relation-ship in which two different microorganisms occupy the same ecologic niche, but have absolutely no effect on each other is:

Answer 25

neutralism