Deck 23: Eukaryal Microbe Pathogenesis

Question 1

What do humans ingest in food or water in in order to contact Giardia lamblia?

A)trophozoites
B)gametocytes
C)sporozoites
D)schizonts
E)cysts

Answer 1

E

Question 2

How do spores of the causative agent of Dutch elm disease,Ophiostoma novo-ulmi,spread from a dead infected tree to a non-infected tree?

A)an airborne route of transmission
B)woodpeckers
C)an elm beetle
D)squirrels that live in the dead tree
E)mosquitos

Answer 2

C

Question 3

How do trypanosomes evade host defense mechanisms to cause disease?

A)By killing phagocytic cells.
B)By avoiding phagocytosis through capsule production.
C)By replicating inside white-blood cells.
D)By binding the Fc region of immunoglobulins.
E)By an antigenic variation mechanism.

Answer 3

E

Question 4

How do many phytopathogenic fungi obtain nutrients from plant host cells?

A)By excreting enzymes to breakdown plant cell walls.
B)By excreting exotoxins to kill plant cells.
C)By stimulating the host cells to excrete sugars.
D)By stimulating the plant to increase photosynthesis.
E)By producing proteins to scavenge nutrients away from the plant.

Question 5

How does the fungus Amanita cause disease?

A)From the ingestion of a potent toxin it produces.
B)Through the invasion of the intestinal mucosa.
C)By inhalation of fungal spores that germinate in the lungs to cause pneumonia.
D)By invading the neuronal tissue and causing disease.
E)Through the invasion of muscle cells.

Question 6

Trypanosoma brucei gambiense is the causative agent of what disease?

A)malaria
B)African sleeping sickness
C)yellow fever
D)diarrheal disease
E)dengue fever

Question 7

The toxin α-amanitin specifically inhibits this.

A)DNA polymerase.
B)RNA polymerase II.
C)cell membrane synthesis.
D)ribosomal function.
E)DNA helicase.

Question 8

Which of these is an example of an opportunistic disease-causing protozoan in AIDS patients?

A)Plasmodium vivax
B)Trypanosoma brucei
C)Giardia lamblia
D)Entamoeba histolytica
E)Toxoplasma gondii

Question 9

What is the key mechanism in establishing giardial diarrhea?

A)The excretion of an enterotoxin by Giardia.
B)The destruction of intestinal epithelial cells by Giardia.
C)The attachment of Giardia trophozoites to intestinal epithelia.
D)The invasion of Giardia into the intestinal epithelial cells.
E)The production of a cytolytic exotoxin by Giardia.

Question 10

AIDS patients are more susceptible to developing pneumonia caused by ___________ than individuals with a normal functioning immune system.

A)Streptococcus pneumoniae
B)Staphylococcus aureus
C)Haemophilus influenza
D)Pneumocystis jiroveci
E)Klebsiella pneumoniae

Question 11

The "definitive host" for Plasmodium falciparum is the host in which it:

A)causes malaria.
B)completes its sexual life cycle.
C)replicates asexually.
D)goes through its complete life cycle.
E)causes a mild form of malaria.

Question 12

How is Trypanosoma brucei gambiense,transmitted to humans?

A)By a water-borne route.
B)By an aerosol route.
C)Through the bite of a tsetse fly.
D)By direct contact.
E)Through sexual contact.

Question 13

A predator likely to be affected by saxitoxin in the wild is:

A)Alexandrium minutum
B)Acartia tonsa
C)Amanita phalloides
D)Amanita muscaria
E)Trypanosoma brucei

Question 14

The plant pathogen Magnaporthe grisea produces specialized cell structures called ____________ that penetrate the plant cuticle to allow the fungi to invade the plant.

A)hyphae
B)conidia
C)ascospores
D)appressoria
E)cysts

Question 15

Why are trypanosomes not endemic to the United States?

A)Because of an active vaccination program.
B)Because the insect vector is absent.
C)Because the weather is too cold.
D)Because antibiotics keep the disease in check.
E)Because of rigorous water treatment standards.

Question 16

Candida albicans frequently causes the disease ___________ in AIDS patients,which is characterized by thick white lesions in the mouth.

A)cankers
B)thrush
C)leishmaniasis
D)chancre
E)impetigo

Question 17

Humans typically come into contact with saxitoxin through the ingestion of:

A)seawater contaminated with red-tide algae
B)raw shellfish.
C)contaminated drinking water.
D)inadequately treated sewage water
E)raw beef.

Question 18

What is the causative agent of malaria?

A)a fungus
B)a virus
C)a bacterium
D)a protozoan
E)a helminth

Question 19

By which route is Giardia lamblia transmitted from infected host to susceptible host?

A)aerosol
B)direct contact
C)vector-borne
D)fecal-oral
E)blood-borne

Question 20

Which of these may result in Candida albicans causing disease in immunocompetent people?

A)A change in the microflora because of antibiotic therapy.
B)A change in the antigenicity of the fungus.
C)The production of a potent exotoxin by the fungus.
D)Consumption of contaminated water containing the fungus.
E)Sexual transmission of the fungus.

Question 21

How does transmission of Ascaris lumbricoides occur?

A)By eating improperly cooked pork.
B)Through a respiratory route.
C)By consuming fecal-contaminated food or water.
D)Through a blood-borne route.
E)Via an arthropod vector.

Question 22

Select the incorrect statement:

A)Parasitophorous vacuoles are found within cytostomes
B)Cytostomes are found within Parasitophorous vacuoles
C)Elisa tests are routinely used to diagnose malaria
D)Microscopic Plasmodium species identification will require specially trained individuals
E)All are incorrect statements

Question 23

A species which uses HC toxin as a virulence factor is:

A)Alexandrium minutum
B)Acartia tonsa
C)Amanita phalloides
D)Cochliobolus carbonum
E)Trypanosoma brucei

Question 24

Malaria was eradicated in the United States by 1951.This was primarily accomplished by:

A)successful vaccine development.
B)the use of preventative drugs.
C)successful antibiotic therapy.
D)reduction of the mosquito population.
E)the quarantine of infected individuals.

Question 25

What resulted from the deletion of the merozoite surface protein 7 gene (msp7)in a strain of Plasmodium falciparum?

A)Poor replication of the pathogen in the liver.
B)Poor attachment to and invasion of red blood cells.
C)Poor differentiation of merozoite into gametocytes.
D)The disruption of the life cycle in the mosquito.
E)Increased destruction of red blood cells.

Question 26

Most of the clinical symptoms observed in an individual with malaria result from this activity.

A)Sporozoite infection of the liver.
B)Sporozoite infection of muscle.
C)Lysis of red blood cells by merozoites.
D)Lysis of red blood cells by sporozoites.
E)Parasite infection of the brain cells.

Question 27

Which of these is used in the most reliable test for the diagnosis of malaria in an individual?

A)An ELISA-based test of a serum sample.
B)Microscopic examination of a stained blood smear.
C)A biopsy of liver tissue.
D)Antibody-coated latex beads to test a blood sample.
E)Tissue culture techniques for growth of the pathogen from a blood sample.

Question 28

50% inhibition of RNA pol II occurs in humans exposed to 10-25 ng/ml of α-amanitin but it takes only 7 ng/ml of α-amanitin to achieve the same result in nematodes.Can you suggest a possible explanation for this observation?

A)Worms are more closely related to the fungus that humans are
B)Humans are more closely related to the fungus that worms are
C)Fungal hyphae and nematodes may naturally compete for soil nutrients
D)Humans have evolved resistance to the toxin
E)Worms have evolved resistance to the toxin

Question 29

Hemozoin is produced:

A)Within the ookinete of Plasmodium
B)Within the mosquito salivart gland
C)As a product of MSP7 catalysis
D)Within the parasitophorous vaculole
E)In pesticide resistant mosquitoes only

Question 30

The merozoite form of Plasmodium species specializes in the digestion and use of _____________ as its primary nutrient source.

A)DNA
B)RNA
C)membrane lipids
D)mitochondria
E)hemoglobin

Question 31

When an Anopheles mosquito feeds on a person with malaria,it ingests the ___________ form of the parasite.

A)gametocyte
B)sporozoite
C)merozoite
D)oocyst
E)zygote

Question 32

Sandflies are vectors for:

A)Malaria
B)Acute African sleeping sickness
C)Chronic African sleeping sickness
D)Leishmaniasis
E)Chagas disease

Question 33

Virulence mechanisms possessed by Plasmodium species include the ability:

A)To facilitate pyrimidine nucleoside precursor uptake
B)To facilitate purine nucleoside precursor uptake
C)To add acetyl groups to histone proteins
D)To inhibit the action of RNA polymerase II
E)To remove acetyl groups present on histone proteins

Question 34

A species which uses saxitoxin as a defense is:

A)Alexandrium minutum
B)Acartia tonsa
C)Amanita phalloides
D)Amanita muscaria
E)Trypanosoma brucei

Question 35

What is Ascaris lumbricoides,a helminth that causes ascariasis,commonly called?

A)hookworm
B)roundworm
C)tapeworm
D)pinworm
E)whipworm

Question 36

The anti-malarial drug chloroquine was used for years to prevent malaria.This drug worked by inhibiting the formation of hemozoin in the parasite,which resulted in:

A)destabilization of the parasitic cytoplasmic membrane.
B)the inhibition of transcriptional processes in the parasite.
C)the inhibition of translational processes in the parasite.
D)accumulation of toxic metabolic products in the parasite.
E)destabilization of the endoplasmic reticulum in the parasite.

Question 37

Plasmodium falciparum uses this protein to steal nutrients from host cells:

A)HC toxin
B)α-amanitin
C)PfNT1
D)Saxitoxin
E)None is a correct choice

Question 38

Select the correct statement:

A)Parasitophorous vacuoles are found within cytostomes
B)Cytostomes are found within Parasitophorous vacuoles
C)PCR is routinely used to diagnose malaria
D)Microscopic Plasmodium species identification does not require specially trained individuals
E)All are correct statements

Question 39

Name for the infective stage of the malarial parasite in the mosquito.

A)gametocyte
B)sporozoite
C)merozoite
D)oocyst
E)zygote

Question 40

HC toxin's mechanism of action appears to be:

A)To facilitate pyrimidine nucleoside precursor uptake
B)To facilitate purine nucleoside precursor uptake
C)To add acetyl groups to histone proteins
D)To inhibit the action of RNA polymerase II
E)To remove acetyl groups present on histone proteins

Question 41

α-amanitin has influenced fruit fly evolution because it has contributed to the development of ______________.

A)increased competition for fungal food
B)lowered numbers of parasites infecting the flies
C)immunity to the toxin in organisms that feed on fruit flies
D)lower populations of fruit flies
E)increased mutations in fruit fly genomes

Question 42

Which of these may contribute to Toxoplasma gondii causing severe disease in individuals? (Select all that apply)

A)A change in the microflora because of antibiotic therapy.
B)Immunosuppression nattural to pregnancy
C)Altered immune status due to administration of immunosuppressive drugs
D)Consumption of contaminated water containing the fungus.
E)Altered immune status of the individual due to HIV

Question 43

The parasite contributing most significantly to amphibian disease throughout the world is:

A)D)falleni
B)D)recens
C)H)aoronymphium
D)B)dendrobatidis
E)X)laevis

Question 44

Malaria has influenced human evolution because it has contributed to the development of ______________ in humans.

A)asthma
B)hemochromatosis
C)sickle cell disease
D)diabetes mellitus
E)myasthenia gravis

Question 45

The parasite which is less likely to infect α-amanitin-resistant fruit fly species is:

A)D)falleni
B)D)recens
C)H)aoronymphium
D)B)dendrobatidis
E)X)laevis

Question 46

Which factors have made it difficult to acchieve world eradication of malaria? (Select all that apply)

A)Mosquito pesticide resistance
B)Plasmodium drug resistance
C)Human drug resistance
D)Climatic conditions such as drought
E)Climatic conditions such as monsoonal weather

Question 47

Which of these worms causes the mildest syndrome?

A)Hookworms
B)Roundworms
C)Whipworms
D)Pinworms
E)Schistosomes

Question 48

Which of these worms causes anemia? (Select all that apply)

A)Hookworms
B)Roundworms
C)Whipworms
D)Pinworms
E)Schistosomes

Question 49

The fungus Pyrenophora tritici-repentis causes disease in wheat.Only strains of P.tritici-repentis that contain the ToxA gene are able to cause disease;other strains are avirulent.The appearance of the toxin gene is recent;how does research indicate this gene was acquired?

A)It is the result of mutation in a pigment gene in the fungus.
B)It is the result of a mutation that up-regulated the expression of the previously non-expressed gene.
C)It was transferred from a pathogenic bacterium to P.tritici-repentis.
D)It was transferred from another pathogenic fungus to P.tritici-repentis.
E)It was acquired through the rearrangement of two other genes in P.tritici-repentis.

Question 50

ELISA tests performed to diagnose malaria are designed to detect: (Select all that apply0

A)Plasmodium lactate dehydrogenase
B)MSP-7
C)Histone deacetylase
D)Hemozoin
E)Surface protein II

Question 51

Which of these may contribute to Candida albicans causing severe disease in individuals? (Select all that apply)

A)A change in the microflora because of antibiotic therapy.
B)A change in the antigenicity of the fungus.
C)Altered immune status due to administration of chemotherapeutic drugs
D)Consumption of contaminated water containing the fungus.
E)Altered immune status of the individual due to HIV

Question 52

Why are individuals who are heterozygous for the sickle cell trait partially protected from developing malaria?

A)They make antibody against the malarial pathogen.
B)Their infected red blood cells become sickled and are destroyed.
C)They develop a strong cell-mediated response against the malarial pathogen.
D)Their red blood cells cannot be infected by the malarial pathogen.
E)Their red blood cells contain very little hemoglobin.

Question 53

The most recent hope that amphibian extinctions may be slowed comes from the discovery of: (Select all that apply)

A)B)dendrobatidis colonization of frogs which appear healthy
B)Bacteria such as J.lividum which produce potent antifungal factors
C)B)dendrobatidis colonization of frogs as long ago as the 1930s
D)Ways to drastically and rapidly reduce climate change
E)New antifungal drugs to treat affected amphidians

Question 54

Identify all forms of Plasmodium which can be isolated from humans: (Select all that apply)

A)Merozoite
B)Gametocyte
C)Sporozoite
D)Ookinete
E)Oocyst

Question 55

What can result from an Ascaris infection in children?

A)Poor nutrient absorption and growth.
B)Damage to the liver.
C)Damage to the heart.
D)Rashes.
E)Damage to the bladder.

Question 56

What is the intermediate host in the life cycle of Schistosoma?

A)mosquito
B)tick
C)body louse
D)freshwater snail
E)cat

Question 57

Which of these worms can damage a wide range of organs and tissues?

A)Hookworms
B)Roundworms
C)Whipworms
D)Pinworms
E)Schistosomes

Question 58

Identify all forms of Plasmodium which can be isolated from mosquitoes: (Select all that apply)

A)Merozoite
B)Gametocyte
C)Sporozoite
D)Ookinete
E)Oocyst

Question 59

Which of these worms infects the most individuals worldwide?

A)Hookworms
B)Roundworms
C)Whipworms
D)Pinworms
E)Schistosomes

Question 60

Which of these conditions will likely ensure an immunocompromised host? (Select all that apply)

A)A change in the microflora because of antibiotic therapy.
B)Immunosuppression natural to pregnancy
C)Altered immune status due to administration of immunosuppressive drugs
D)an individual who is very elderly
E)Altered immune status of the individual due to HIV

Question 61

The life cycle form of the malaria parasite Plasmodium falciparum that is transferred from the mosquito to a human is called a(n)_____________________.

Question 62

The malarial parasite obtains nutrients by digesting ___________ from host red blood cells.

Question 63

Factors which have likely affected the decimation of amphibian species in recent years include:

A)Exposure to novel fungal pathogens
B)Stress because of climate change
C)Overhunting by pet store staff
D)Distribution of frogs to new geographic areas
E)Bacteria such as J.lividum

Question 64

The form of the Plasmodium parasite that infects the red blood cells is called a merozoite.

Question 65

The fusing of gametes of the Plasmodium parasite is completed in the human host.

Question 66

Some eukaryal pathogens have influenced the evolution of their human host.