Microbiology Chapter 10

The most common organisms within the indigenous microflora of the mouth are various species of ________

(alpha)-hemolytic streptococci

Most frequent causes of urethral infections include _____

Chlamydia trachomatis, Neisseria gonorrhoea, and mycoplasmas.

The systematic study of the interrelationships that exist between organisms and the environment

Ecology

Includes all the microbes (bacteria, fungi, protozoa, and viruses) that reside on and within a person

Indigenous microflora (normal flora)

Defined as two dissimilar organisms living together in a close association

Symbiosis

_____ take up temporary residence on and within humans.

Transient microflora

True or False A change in conditions can cause one type of symbiotic relationship to shift to another type.

True

True or False As many as 100 trillion microorganisms could live on and in us at a time.

True

True or False Biofilms are very resistant to antibiotics and disinfectants.

True

True or False Blood, lymph, spinal fluid, and most internal tissues are normally free or microorganism.

True

True or False Destruction of resident microflora disturbs the delicate balance between host and microorganisms.

True

True or False Humans derive benefits from their indigenous microflora.

True

True or False Kidney, ureters, and urinary bladder are usually sterile.

True

True or False Lower respiratory tract is usually free of microbes.

True

True or False Many organisms in the indigenous microflora of humans are considered to be commensals.

True

True or False Middle ear and inner ear are usually sterile.

True

True or False Most relationships between humans and microbes are beneficial, rather than harmful.

True

True or False Outer ear and auditory canal contain the same microorganisms as on the skin.

True

True or False The colon is anaerobic.

True

True or False The male and female reproductive systems are usually sterile, with the exception of the vagina.

True

True or False The parasite may or may not cause disease in the host.

True

True or False Upper respiratory tract has an abundance of microorganisms. Many are harmless, some are opportunistic.

True

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

a. alpha-hemolytic streptococci

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

a. bloodstream

The greatest number and variety of indigenous microbiota of the human body live in or on the _____

a. colon

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

a. indigenous microbiota

Number and variety of microorganisms depend on _______

amount of moisture present, pH, temperature, salinity, and presence of chemical wastes and other microbes.

The delicate balance of the indigenous microflora can be upset by _______

antibiotics, other types of chemotherapy, and changes in pH

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

b. coagulase-negative staphylococci

The distal urethra and its external opening harbor many microbes including ______

bacteria, yeasts, and viruses.

How many species are indigenous microflora composed of?

between 500 and 1000 different species

Bacteria and yeasts used to stabilize the microbial balance are called _____

biotheapeutic agent or probiotics

Indigenous microflora are not found in the _______.

bloodstream

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

c. skin

The _____ (large intestine) contains the largest number and variety of microorganisms of any colonized area of the body.

colon

The greatest number and variety of indigenous microflora of the human body live in the _____

colon

Symbionts are classified as _____

commensal, opportunistic, parasitic

A symbiotic relationship that is beneficial to one symbiont and of no consequence to the other

commensalism

________ is a symbiotic relationship of benefit to one of the symbionts but neither beneficial nor harmful to the other.

commensalism

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

d. all of the above

Escherichia coli living in the human colon can be considered to be a(n): a. endosymbiont b. opportunist c. symbiont d. all of the above

d. all of the above

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

d. all of the above

In the nitrogen cycle, soil organisms called_______ convert the nitrogen in nitrates to nitrogen gas in the atmosphere.

denitrifying bacteria.

Careless dental hygiene may cause:

dental caries, gingivitis, periodontitis

The GI tract is designed for _______

digestion of food, absorption of nutrients, and elimination of undigester materials.

Bacteria found within other microorganisms are known as ______

endosymbionts

A _____ is a living organism that harbors another living organism.

host

Microorganisms are present both on and in our bodies; collectively, they are referred to as our _______

indigenous microflora

The GU tract consists of the _____

kidneys, ureters, urinary bladder, urethra, and parts of the female/male reproductive systems.

Lower respiratory tract

larynx, trachea, bronchi, and lungs

Microbial antagonism means_____

microbes versus microbes

The study of the numerous interrelationships between microbes and the world around them

microbial ecology

A lichen is a classic example of ________

mutualism

A symbiotic relationship that is beneficial to both symbionts

mutualism

Upper respiratory tract

nasal passages and throat

Refers to a symbiotic relationship in which neither symbiont is affected by the relationship

neutralism

The term that best describes a symbiotic relationship in which two different microorganisms occupy the same ecologic niche but have absolutely no effect on the other is _________

neutralism

When two microorganisms occupying the same environment niche have absolutely no effect on each other, it is known as ______

neutralism

In the nitrogen cycle, soil organisms called ________ convert ammonia into nitrates, and nitrites into nitrates.

nitrifying bacteria

Microorganisms play an important role in the cycling of nutrients and elements like _____

nitrogen, carbon, oxygen, sulfur, and phosphorus.

In the nitrogen cycle, bacteria called ________ convert atmospheric nitrogen gas into ammonia in the soil

nitrogen-fixing bacteria

_______ live in the root nodules of legumes such as alfalfa and clover.

nitrogen-fixing bacteria

Bacteria in the colon are mostly ______

obligate aerotolerant and facultative anaerobes.

Many of the microflora of the colon are ______

opportunistic

A symbiotic relationship that is beneficial to one symbiont (the parasite) and detrimental to the other symbiont (the host)

parasitism

________ is a symbiotic relationship of benefit to one of the symbionts, and detrimental to the other.

parasitism

_______ are capable of converting the nitrogen within a dead plant or animal into ammonia in the soil.

saprophytes

Eye is lubricated and cleansed by tears, mucus, and _____

sebum

The organisms in the relationship are referred to as ______

symbionts

Bacterial vaginosis is an example of ________

synergism