part 2

Question 1

two organisms live together in a close partnership

Answer 1

Symbiotic

Question 2

obligatory, dependent; both
members benefit

Answer 2

Mutualism

Question 3

commensal member
benefits, other member
neither harmed nor
benefited

Answer 3

Commensalism

Question 4

parasite
is dependent and
benefits; host is harmed

Answer 4

Parasitism

Question 5

organisms
are free-living; relationships
not required for survival

Answer 5

Non-symbiotic

Question 6

members
cooperate to produce a
result that none of them
could do alone

Answer 6

Synergism

Question 7

actions
of one organism affect
the success or survival
of others in the same
community (competition)

Answer 7

Antagonism

Question 8

• Human body is a rich habitat for symbiotic bacteria, fungi, and a few protozoa called

Answer 8

normal microbial flora

Question 9

ecological association that can exist in human body

Answer 9

Commensal, parasitic, and synergistic
relationships

Question 10

result when organisms attach to a
substrate by some form of extracellular matrix
that binds them together in complex organized
layers

Answer 10

Biofilms

Question 11

Communicate and cooperate in the formation
and function of biofilms

Answer 11

quorum sensing

Question 12

Microbial growth occurs at two levels:

Answer 12

1. growth at a cellular level with increase in size
   2.increase in population

Question 13

Division of bacterial cells occurs mainly through

Answer 13

binary fission

Question 14

Parent cell enlarges, duplicates its chromosome, and
forms a central transverse septum dividing the cell
into two daughter cell

Answer 14

binary fission

Question 15

populations typically display a
predictable pattern over time

Answer 15

growth curve

Question 16

stages in the normal growth

Answer 16

1. lag phase
2. log phase
3. stationary phase
4. death phase

Question 17

‘flat” period of adjustment, enlargement;
little growth

Answer 17

Lag phase

Question 18

a period of maximum
growth will continue as long as cells have adequate
nutrients and a favorable environment

Answer 18

log phase

Question 19

rate of cell growth equals rate of cell
death caused by depleted nutrients and O2, excretion of
organic acids and pollutants

Answer 19

Stationary phase

Question 20

as limiting factors intensify, cells die
exponentially

Answer 20

death phase

Question 21

most simple
* Degree of cloudiness, turbidity, reflects the
relative population size (estimate)

Answer 21

turbidometry

Question 22

count all
cells present; automated or
manual

Answer 22

Direct cell count