MIC 201 Exam 2 2009

Which of the following does not apply to plasmids?
a) they are essential for the growth of the cell
b) they are composed of DNA
c) they multiply independently of the chromosome
d) they may pass from cell to cell in recombinations
e) the fertility factor is a plasmid

Genes existing on plasmids may include those for:
a) DNA synthesis and induction of lysogeny
b) sexduction and capsule production
c) restriction enzymes and ligases
d) antibiotic resistance and toxin production
e) Kreb's cycle enzymes

Okazaki fragments form most often during:
a) the process of sexduction
b) lysogeny of bacteriophage
c) lysogeny of protozoa by viruses
d) the movement of insertion sequences
e) replication of the bacterial chromosome

The rolling circle mechanism of DNA replication takes place:
a) during lysogeny
b) as transposons move about
c) after the mesosome detaches from the cell membrane
d) during bacterial conjugation
e) at the latter stage of viral replication

The deletion or insertion of extra nucleotides during chromosomal replication can lead to:
a) the loss of competence by a bacterium
b) the inability of a bacterium to unite with a virus
c) an overlapping gene situation
d) the formation of sticky ends for genetic engineering experiments
e) mutation due to a shift in the reading frame

[T or F]
In specialized transduction, genes are removed from the bacterial chromosome at the point where the virus is attached.

All of the following biochemicals or structures are essential to the process of genetic engineering except:
a) DNA ligase
b) mitochondria
c) plasmids
d) restriction enzymes
e) live bacteria

A normal flora may be found in all of the following environments except:
a) the stomach and blood
b) the blood and pharynx
c) the pharynx and vagina
d) the vagina and stomach
e) the intestine and nose

The virulence of an organism may be enhanced by all of the following except:
a) its ability to produce exotoxins
b) its ability to overcome body defense
c) its ability to spread through tissues
d) its ability to grow on artificial laboratory media
e) its ability to produce endotoxins

Invasiveness refers to the ability of a parasite to:
a) produce aggressive factors
b) add to its virulence by transduction
c) penetrate tissues and cause structural damage
d) multiply only within anaerobic environments
e) convert toxins to toxoids

In the period of prodromal symptoms:
a) the disease is at its height
b) the individual may experience nausea, fever, and headache
c) the disease has begun to disappear
d) the individual is infected but shows no signs of the disease
e) specific symptoms are present

Which of the following would be considered as a secondary bacterial disease:
a) cholera
b) pneumonia
c) tuberculosis
d) dysentery
e) tetanus

The degree to which an organism is able to cause disease is referred to as its:
a) virulence
b) pathogenicity
c) communicability
d) defervescence

Endotoxins shock may be observed to follow when:
a) the removal of acetylcholine from the the synapse
b) interruption of the metabolism of Gram positive bacteria
c) injection of antitoxins to the body
d) antibiotic treatment of a disease due to Gram negative bacteria
e) interactions between enterotoxins and neurotoxins

Opsonins may be described as:
a) types of white blood cells
b) antibodies that enhance the efficiency of phagocytosis
c) types of endotoxins produced by bacteria
d) cellular organelles in which antibodies are produced
e) types of bacterial exotoxins

The movement of genetic segments is believed to influence:
a) the type of lymphokines that evolve in cellular immunity
b) the variety of antibodies that B lymphocytes produce
c) the interaction between phagocyte and immune cells at the lymph nodes
d) the formation of memory B lymphocytes from plasma cells
e) the formation of memory T lymphocytes

The nonspecific inhibitor lysozyme acts on bacteria by:
a) inhibiting protein synthesis in all bacteria
b) stimulating interferon production
c) destroying the cell wall of Gram positive bacteria
d) interfering with the mobility of bacteria
e) inhibiting the activity of the Kreb's cycle enzymes

The cell surface receptor of a B lymphocyte is a:
a) molecule of polysaccharide
b) cluster of CMI antigens
c) set of genes similar to transposons
d) antibody molecule
e) molecule of nucleic acid similar to DNA

The phagocyte-binding site of an antibody molecule is part of the:
a) fab fragment
b) variable domain
c) light chain
d) Fc fragment

Humans do not contract hog cholera, and hogs do not contract polio. These are examples of:
a) racial immunity
b) autoimmunity
c) heterophile immunity
d) species immunity

[T or F]
The polymorphonuclear cells, monocytes, and RES cells are primarily concerned with phagocytosis.

An individual generally acquires natural active immunity after:
a) an injection of IgG
b) an infusion of T lymphocytes
c) treatment with an oral vaccine
d) suffering an illness
e) an injection of IgA

Antibodies produced against bacterial pili would inhibit:
a) capsular polysaccharide production
b) penetration of the bacteria through human tissues
c) destruction of human red blood cells
d) bacterial motion
e) attachment of bacteria to human tissues

Lattice formation is a characteristic of:
a) the enzyme-linked immunoassay
b) precipitation reactions
c) the fluorescent antibody technique
d) the complement fixation test
e) agglutination reactions such as the Widal test

[T or F]
Booster immunizations raise the level of antibodies in a recipient by stimulating the memory cells to bring about the secondary anamnestic response.

[T or F]
Our bodies are protected from producing antibodies against our own antigens by specific immune tolerance which continually removes those lymphocytes that would produce a response to our own antigens.

The titer of antibodies reflects all of the following except:
a) the amount of antibodies present in the serum
b) the progress of a disease
c) the level of immunity in a patient
d) the degree of activity of T lymphocytes
e) the activity of B lymphocytes

The most abundant component of serum complement is one that produces a small fragment upon activation that is involved with chemotaxis and anaphylaxis is:
a) C1
b) C2
c) C3
d) C4
e) C9

Drying of the skin with erythema and scaling after an exposure to formaldehyde may be the result of:
a) contact dermatitis
b) anaphylactic hypersensitivity
c) allergy to penicillin
d) an autoimmune disease
e) serum sickness

[T or F]
The graft-vs-host rejection is observed in bone marrow transplants when immune cells in the marrow form immune products against host cells, following suppression of the host's immune system.

All of the following are associated with type IV hypersensitivity reactions except:
a) an induration
b) accumulation of T lymphocytes at the antigen site
c) IgE
d) release of lymphokines
e) infection allergy

Tumor cells may be identified by:
a) their possession of antigens not in surrounding cells
b) their usually low rate of mitosis
c) their inability to secrete interferon
d) their production of all five types of antibodies
e) their display of contact inhibition

[T or F]
Hemolytic disease of the newborn will generally not occur during a woman's first pregnancy because her initial exposure to Rh antigens occurs during the birth of her first child.

[T or F]
The antigens in RhoGAM unite with antibodies entering the fetal circulation and prevent development of hemolytic disease of the newborn.

Edema is a condition in which:
a) a rash consisting of both wheals and flares is present
b) wheezing and stressed breathing are symptoms
c) the skin becomes swollen about the eyes, wrists, and ankles
d) IgG forms complexes with antigens near the site of the latter's entry into the body

The exotoxin Corynebacterium diphtheriae:
a) destroys Kreb's cycle enzymes in tissues
b) interferes with ATP production in infected tissues
c) links together adjacent adenine molecules in DNA
d) interferes with membrane transport in human cells only
e) interrupts proteins synthesis in epithelial cells

Mycobacterium tuberculosis is unique because it:
a) must be lysogenized before it can cause disease
b) is acid-fast
c) forms a capsule
d) has no cell wall

Streptococcus pyogenes is a(n):
a) alpha-hemolytic streptococcus
b) beta-hemolytic streptococcus
c) gamma-hemolytic streptococcus
d) delta-hemolytic streptococcus

Cases of Legionnaire's disease have been linked to bacteria which:
a) are present in the urine
b) accumulate in standing water
c) appear as staphylococci
d) cannot be cultivated in the laboratory
e) have a cell wall but no cell membrane

[T or F]
Although Haemophilus influenzae does not cause influenza, it often causes a secondary infection in patients who have influenza.

Cases of diphtheria are characterized by:
a) pseudomembrane formation in the respiratory tract
b) kidney failure
c) destruciton of the tissues of the alveolar sacs
d) formation of deep ulcers of the gastrointestinal tract
e) none of these

A child suffering from repeated bouts of a violent, high-pitched cough is brought to her physician's office. The physician is likely to diagnose an infection of:
a) Bordetella pertussis
b) Streptococcus pneumonia
c) Mycobacterium tuberculosis
d) Haemophilus influenzae

A distinguishing feature of disease caused by Brucella species is the:
a) extensive diarrhea
b) paralysis of the lower body trunk
c) alternating periods of fever and relief
d) rose spots on the skin surface
e) slow development of arthritis in the joints

The following are assocaited with botulism except:
a) bacterial endospores
b) potent neurotoxin
c) home-canned food
d) blurred vision
e) muscle spasms

[T or F]
Shellfish may be a source of cholera because they filter bacteria out of the water and concentrate the bacteria in their tissues.

Antibiotics are of no value in treating botulism because:
a) the person is intoxicated rather than infected
b) the bacteria are generally resistant to antibiotics
c) antibiotics cannot reach the toxins in the nerve endings
d) the intestine rapidly eliminates the antibiotic before it can function
e) no anti-botulism antibiotic has been found yet

The important consideration in treating patients who have bacterial dysentery is:
a) replacement of lost fluids
b) a blood transfusion to relieve the anemia
c) removal of coronary thromboses
d) prevention of the spread of the disease through respiratory secretions
e) removal oft he affected limb by amputation

The staphylococcal enterotoxins:
a) is composed solely of carbohydrates
b) is among the most heat-resistant exotoxins
c) can be destroyed by placing food in the refrigerator
d) is produced in the human intestine
e) is more potent than the botulism toxin

[T or F]
Poultry products are important sources of food infections because Salmonella serotypes cause a significant number of infections in chickens and turkeys.

[T or F]
Cases of infantile traveler's diarrhea are generally linked to species of Clostridium that contaminate water supplies.

Extra:
How is environmental genomics contributing to a better world?