Deck 11: Eukaryotic Microbes and Invertebrate Infectious Agents

Question 1

Which of the following would be considered "true" microbes?

A) nematode
B) cestodes
C) trematodes
D) fungi

Answer 1

D

Question 2

Fungal filaments associated with the root systems of trees that expand the trees' access to water and nutrients are known as

A) mycorrhizae.
B) molds.
C) chitin.
D) saprophytes.

Answer 2

A

Question 3

The group of organisms that includes ciliates,dinoflagellates,and apicomplexans is known as

A) fungi.
B) amebas.
C) trypanosomes.
D) alveolates.

Answer 3

D

Question 4

The cell shown is best described as a

A) gamete.
B) prokaryote.
C) diploid cell.
D) haploid cell.

Question 5

Fungi that form spore-dispersing asci are known as

A) basidiomycetes.
B) zygomycetes.
C) microsporidia.
D) ascomycetes.

Question 6

The fungal structure shown is best described as a

A) hyphapseudopod.
B) mycelium.
C) mushroom.
D) fruiting body.

Question 7

How do filamentous fungi grow in length?

A) Their hyphae undergo mitosis without cell division.
B) Their hyphae undergo meiosis to produce new cells.
C) They produce asci by mitosis without cell division.
D) They produce asci by meiosis without cell division.

Question 8

When comparing sexual reproduction to asexual reproduction,which of the following is an advantage of sexual reproduction?

A) Sexual reproduction generates fewer diverse cell surface proteins and is less likely to activate an immune response.
B) Sexual reproduction requires fewer resources that may be useful when nutrients are depleted.
C) Sexual reproduction produces haploid vegetative cells, which are smaller than diploid vegetative cells.
D) Sexual reproduction increases genetic diversity, which may be useful in a changing environment.

Question 9

The ability of fungi to digest lignin is important in the

A) production of bread.
B) production of beer.
C) decomposition of wood.
D) decomposition of animal bodies.

Question 10

Why is it frequently more difficult to treat fungal infections in humans than it is to treat bacterial infections?

A) The cells found in fungi and humans are more similar than cells of bacteria and humans.
B) Humans have not developed medications capable of targeting fungi.
C) Fungi normally grow in and on humans, and treating fungal infections would cause death of the human.
D) Fungi undergo evolution at a much faster rate than bacteria do.

Question 11

On an evolutionary timeline,which of the following organisms appeared first?

A) cyanobacteria
B) proto-algae
C) algae
D) plants

Question 12

When comparing invertebrate parasites to "true" microbes,which of the following is found in invertebrate parasites only?

A) fully differentiated organ systems
B) cells with mitochondria
C) macroscopic forms
D) cells with nuclei

Question 13

Which of the following would be considered invertebrate parasites?

A) helminths
B) amebas
C) metamonads
D) algae

Question 14

A major group of microbial eukaryotes that contains chloroplasts related to those of plants and is found as a single cell or sheet is

A) fungi.
B) algae.
C) alveolates.
D) trypanosomes.

Question 15

Cyanobacteria engulfed by an ancient proto-alga lead to the development of ________ in both algae and plants.

A) mitochondria
B) a nucleus
C) ribosomes
D) chloroplasts

Question 16

One drug target for antifungals is the membrane lipid

A) chitin.
B) hyphae.
C) triazole.
D) ergosterol.

Question 17

Which of the following occurs during gamete formation but NOT during asexual reproduction?

A) replication of all chromosomes
B) paired chromosomes condensing into short rods
C) separation of pairs of homologs
D) formation of nuclear membranes around groups of chromosomes

Question 18

Which of the following best describes how fungi obtain nutrition?

A) Fungi use chloroplasts for photosynthesis.
B) Fungi secrete digestive enzymes and absorb broken-down molecules.
C) Fungi use phagocytosis to transport large molecules across their cell membrane.
D) Fungi harness cyanobacteria to receive carbon and other nutrients.

Question 19

The parasite that causes malaria has a complex life cycle involving both a definitive and an intermediate host.This parasitic protist also contains an elaborate cortex.This parasite is best categorized as a(n)

A) fungus.
B) trypanosome.
C) alveolate.
D) alga.

Question 20

Aspergillus and histoplasmosis infections are both caused by

A) opportunistic skin contact with fungi.
B) smoking tobacco contaminated with fungal spores.
C) swimming in contaminated water.
D) inhalation of fungal spores.

Question 21

On an evolutionary timeline,which of the following organisms appeared last?

A) cyanobacteria
B) proto-algae
C) algae
D) plants

Question 22

In the illustrated life cycle of the trypanosome,which of the following forms is nondividing?

A) slender
B) stumpy
C) procyclic
D) epimastigote

Question 23

Which of the following organisms lacks the ability to use aerobic cellular respiration?

A) Giardia lamblia
B) Caenorhabditis elegans
C) Toxoplasma gondii
D) Taenia solium

Question 24

On a trip to a region of Asia where snails commonly ingest trematode eggs,Rebecca refuses to eat escargot,cooked snails,offered by her roommate.Instead,Rebecca goes fishing because she feels it would be safer to eat fresh fish.Unfortunately,she undercooks the fish and develops a trematode infection.What is the most likely explanation for her infection?

A) Free-swimming larvae released by snails in the water developed into a secondary form within the fish.
B) The flesh of the fish she ate contained trematode eggs that developed into larvae within her intestine.
C) Her fish dinner was most likely contaminated by fecal matter in the water because trematode transmission is through a fecal-oral route.
D) There were dormant trematodes encysted within the flesh of the fish she ate.

Question 25

In the illustrated life cycle of the trypanosome,which of the following forms proliferates within the definitive host?

A) slender
B) stumpy
C) procyclic
D) epimastigote

Question 26

A free-living soil ameba may contaminate contact lens solutions and cause amebic keratitis.What is the genus name of one common causative agent of amebic keratitis?

A) Acanthamoeba
B) Entamoeba
C) Babesia
D) Toxoplasma

Question 27

The image shown indicates two paramecia of opposite mating types during one stage of conjugation in which haploid micronuclei are exchanged.Which of the following statements accurately describes the two cells after this stage is complete?

A) Both cells are haploid.
B) Both cells are diploid.
C) One cell is haploid and the other is diploid.
D) Both cells become gametes.

Question 28

The organism shown in this figure is a(n)

A) nematode.
B) cestode.
C) trematode.
D) arthropod.

Question 29

Trypanosoma brucei,the parasite that causes African sleeping sickness,is carried by

A) deer ticks.
B) Anopheles mosquitoes.
C) tsetse flies.
D) bedbugs.

Question 30

Filamentous amebas

A) form inorganic shells made of calcium carbonate.
B) contain large, bulky pseudopods.
C) move using cytoplasmic streaming.
D) utilize chloroplasts for photosynthesis.

Question 31

What is the function of the apical complex on a merozoite form of Plasmodium falciparum?

A) The apical complex is used for aerobic cellular respiration.
B) The apical complex is used to allow a merozoite to enter a red blood cell.
C) The apical complex is used to allow asexual reproduction.
D) The apical complex is used to provide energy for flagella.

Question 32

Giardia lamblia and Trichomonas vaginalis are both metamonads.One similarity between the two species is

A) the presence of cilia.
B) the presence of flagella.
C) the production of cysts.
D) their ability to cross the placenta.

Question 33

Which of the following would be most likely to stop transmission of Plasmodium falciparum and P.vivax to humans?

A) ensure access to clean drinking water
B) provide mosquito netting for beds
C) check for ticks after walking in wooded areas
D) eliminate bedbugs from sleeping quarters

Question 34

The organism shown is designed for living

A) within the small intestine.
B) on the outer surface of the body.
C) within red blood cells.
D) on the outer surface of the liver.

Question 35

What is the function of the process shown in the life cycle of Entamoeba histolytica?

A) This process forms a cyst that leaves the host and remains viable in water supplies for weeks.
B) This process forms a trophozoite that leaves the host and remains viable in water supplies for weeks.
C) This process allows an ingested amebic trophozoite to develop into a cyst that can feed on red blood cells.
D) This process allows an ingested amebic cyst to develop into a trophozoite that can feed on red blood cells.

Question 36

Amoeba proteus,a lobed ameba,most likely moves by using

A) flagella.
B) cilia.
C) cytoplasmic streaming.
D) needlelike pseudopods.

Question 37

Which of the following is a characteristic shared by mites,ticks,and lice?

A) Mites, ticks, and lice are all insects.
B) Mites, ticks, and lice are all vectors for serious disease agents.
C) Mites, ticks, and lice are all ectoparasites.
D) Mites, ticks, and lice all deposit eggs within the skin.

Question 38

Blood and fecal samples are collected from a man with dysentery to determine the causative agent and appropriate treatment.Which of the following would most clearly indicate amebic infection?

A) immunological tests indicating the presence of Shigella
B) a Wheatley's trichrome stain indicating a protozoa with ingested red blood cells
C) a Gram stain indicating the presence of Gram-negative bacteria
D) an endospore stain indicating the presence of endospores

Question 39

Which of the following is unique to ciliates?

A) presence of cilia
B) ability to use endocytosis
C) microtubules within cytoplasm
D) maintenance of two types of nuclei

Question 40

Why is perianal itching significant in the life cycle of pinworms?

A) When a host scratches the anus, pinworm larvae enter the bloodstream.
B) Eggs are trapped under fingernails and transferred to new hosts.
C) Scratching allows mature worms to break through the surface of the skin.
D) Transmission of pinworms ends when the host scratches the anus.

Question 41

The major group of alveolates that possesses two whiplike flagella and includes species that cause "red tide" is known as ________.

Question 42

Obligate parasites with a single flagellum,a complex life cycle,and unique organelles called "kinetoplasts" are known specifically as ________.

Question 43

CASE HISTORY
Brianna,a 22-year-old college student,had returned recently from spring break at the beach in Acapulco,Mexico.She presented at the college clinic complaining of severe abdominal cramps and fever.She also had nausea and bloody diarrhea with mucus.The nurse practitioner collected stool samples and sent them to the laboratory for analysis.Cultures were negative for bacterial pathogens.A trichrome stain was performed,revealing amebas of the trophozoite (active feeding)stage.The stained amebas contained ingested red blood cells.The appearance of the amebas was characteristic of Entamoeba histolytica,the cause of amebic dysentery (bloody diarrhea),or intestinal amebiasis.Brianna was treated with paromomycin (an aminoglycoside that inhibits protein synthesis)for seven days,and her symptoms resolved.
Stained amebas isolated from Brianna's fecal sample indicated amebas in the trophozoite stage.At what life cycle stage did she likely ingest the parasite? Why are other forms less likely?

Question 44

Describe the shared evolutionary event that led to chloroplasts in both algae and plants.

Question 45

CASE HISTORY
Frank,a 45-year-old man,visited the hospital with respiratory distress and a high fever.Frank had diabetes mellitus and had smoked for 25 years.His white blood cell count was 24,000/ml and his c-reactive protein was 24 mg/ml,both signs that his immune system was fighting an infection.His chest X-ray showed an abnormal shadow,and his chest computed tomography (CT scan)showed thickened bronchial walls.He was coughing up black sputum.The physician prescribed an antibiotic,cefotiam hydrochloride,but Frank's condition worsened.By the tenth day,he was producing 100 ml of sputum a day,and the CT scan of his lung showed multiple lesions (clouded regions).Since antibacterial antibiotics had failed,Frank was tested for fungi.A culture of his sputum and PCR amplification of fungal DNA revealed the fungus Aspergillus fumigatus.Frank was treated with the antifungal agents itraconazole,meropenem trihydrate,and amphotericin b,but he died on the 25th day.
What is the most likely cause of Frank's deterioration following the use of an antibiotic agent?

A) Frank was allergic to the antibiotic used.
B) The infection would have progressed at the same rate regardless of the use of this antibiotic.
C) Killing of the fungal cells causing the infection induced a severe immune response.
D) Frank acquired a secondary bacterial infection.

Question 46

What distinguishing characteristic places helminths and arthropods under the category of "eukaryotic microbiology" and outside of the category of "true" microbes?

Question 47

Describe two positive impacts fungi have on our environment.

Question 48

Giardias and trichomonads are both examples of ________.

Question 49

You are looking at a group of unicellular organisms under a microscope and are asked to determine whether the organisms are fungi or algae.Name one visible feature that would allow you to make this determination and explain the significance of that feature in the lifestyle of the organism.

Question 50

Lung diseases caused by filamentous fungi such as Aspergillus fumigatus occur when ________ germinate and grow into fuzzy colonies within tissues.

Question 51

Isolda travels from her home in Texas to Mexico to visit extended family.During her trip she becomes ill with amebic dysentery after drinking contaminated water.Contrast the form of ameba cell she most likely ingested with the form of ameba cell found within her intestine.

Question 52

How is the development of a hookworm larva different from the development of a pinworm larva?

Question 53

Arthropods that attach to the surface of a human or other vertebrate are referred to as ________.

Question 54

A single-celled eukaryotic microbe proliferating by mitosis is undergoing ________ reproduction.

Question 55

Branching tufts of filamentous fungal hyphae form structures known as ________.

Question 56

CASE HISTORY
Dotty was the two-year-old daughter of a Texas petroleum executive.The family included four children and three dogs.Dotty played outdoors with the other children and ranch animals.She developed a habit of scratching herself on her bottom.Her nanny tried to discourage the habit but did not check further.Within a month,Dotty's mother,an attorney for the petroleum firm,noticed that other members of the family had developed a similar habit,which they ascribed to discomfort with the humid summer.One evening when the nanny was out,Dotty's mother changed her daughter's diaper and noticed white threadlike worms a few millimeters long.A trip to the pediatrician revealed pinworms as well as pinworm eggs.The eggs were observed on a "tape test," a piece of tape that was pressed to Dotty's anus and then placed on a slide for light microscopy.The physician prescribed mebendazole (a microtubule inhibitor)for the entire family,including the nanny and the maid who served dinner.Dotty's mother asked about the dogs;she was told that dogs do not carry pinworms,although they do carry other worms transmissible to humans.Since the drug mebendazole affects only mature worms,further treatment two weeks later was required to attack the eggs and immature worms that had grown in that time.Ultimately,it took six months of treatments to eliminate the infection from the household.
How could Dotty's pinworm infection have been transmitted to other members of the family? Give specific examples of potential transmission in a household.

Question 57

Lobed amebas and filamentous amebas are differentiated by the form of their ________.

Question 58

Describe how the parasites that cause malaria are able to evade an immune response during an infection.