Chapter 12

10) In Table 12.1, which of these spores are asexual spores?

A) 1, 4, 5, 6, 7

45) You see acid-fast oocysts in a fecal sample from a patient who has diarrhea. What is the MOST likely cause?

A) Cryptosporidium

5) Which of the following statements regarding lichens is FALSE?

A) Lichens are a mutualistic relationship between a fungus and a protozoan.

1) Which of the following statements regarding fungi is FALSE?

A) Most fungi are pathogenic for humans.

35) Which of the following is a nucleated, unicellular organism that, if you changed the incubation temperature, would form filaments with conidiospores?

A) ascomycete

42) Ringworm is caused by a(n)

A) fungus.

46) A wolf kills a deer that is infected with ________ of Echinococcus granulosis in its liver and eats it. After consuming the deer, the wolf's intestine becomes filled with a number of ________ produced from scoleces. These eventually release eggs into the wolf's intestines, which are released in its feces.

A) hydatid cysts; proglottids

10) Most cases of hookworm infection are acquired by ingestion of adult forms in contaminated food or water.

Answer: FALSE

4) The Platyhelminthes group includes roundworms, tapeworms, and flukes.

Answer: FALSE

7) In helminth life cycles, the organism that harbors the adult sexually reproductive phase of the parasite is called the intermediate host.

Answer: FALSE

9) The insect vectors have six legs and include spiders, ticks, mosquitoes, and lice.

Answer: FALSE

12.2 True/False Questions 1) Plasmogamy, karyogamy, and meiosis are stages of the fungal sexual life cycle.

Answer: TRUE

2) Arthropod vectors are blood-sucking animals such as ticks, lice, and fleas that transmit microbial pathogens.

Answer: TRUE

3) Cercariae, metacercaria, and redia are all life cycle stages of trematodes.

Answer: TRUE

5) Some species of dinoflagellates produce neurotoxins that cause fish kills and red tides.

Answer: TRUE

6) Both the cellular slime molds and the plasmodial slime molds are members of the phylum Amoebozoa.

Answer: TRUE

8) The sporozoite, merozoite, gametocyte, and ring stages are all part of the Plasmodium life cycle.

Answer: TRUE

43) Yeast infections are caused by

B) Candida albicans.

12) Which of the following statements regarding protozoa is FALSE?

B) Nearly all protozoa cause disease.

26) All of the following are characteristic of algae EXCEPT which ONE of the following?

B) They are currently classified as plants.

4) Seventeen patients in ten hospitals had cutaneous infections caused by Rhizopus. In all seventeen patients, Elastoplast bandages were placed over sterile gauze pads to cover wounds. Fourteen of the patients had surgical wounds, two had venous line insertion sites, and one had a bite wound. Lesions present when the bandages were removed ranged from vesiculopustular eruptions to ulcerations and skin necrosis requiring debridement. Fungi are more likely than bacteria to contaminate bandages because they

B) can tolerate low-moisture conditions.

33) You observe a mass of amoeba-like cells that swarm together, form a stalk, and produce spores. This is a(n)

B) cellular slime mold.

13) In mid-December, a woman with insulin-dependent diabetes who had been on prednisone fell and received an abrasion on the dorsal side of her right hand. She was placed on penicillin. By the end of January, the ulcer had not healed, and she was referred to a plastic surgeon. On January 30, a swab of the wound was cultured at 35°C on blood agar. On the same day, a smear was made for Gram staining. The Gram stain showed large (10 µm) cells. Brownish, waxy colonies grew on the blood agar. Slide cultures set up on February 1 and incubated at 25°C showed septate hyphae and single conidia. The most likely cause of the infection is a

B) dimorphic fungus.

21) Three weeks after a river rafting trip, three family members experienced symptoms of coughing, fever, and chest pain. During the rafting trip, the family had consumed crayfish that they caught along the river banks. An examination of the patients' sputum revealed helminth eggs, and serum samples were positive for antibodies to Paragonimus. All of the family members recovered following treatment with praziquantel. In the Paragonimus life cycle,

B) humans are the definitive host and crayfish are the intermediate host.

49) Infecting more than 2 billion people worldwide, ________ are the most common causes of chronic infectious diseases.

B) intestinal roundworms

29) Giardia and Trichomonas are unusual eukaryotes because they

B) lack mitochondria.

47) When we say that a human is a dead end host for a parasite, we mean

B) the infected human is highly unlikely to transmit the infection to another organism.

39) The cells of plasmodial slime molds can grow to several centimeters in diameter because

B) they distribute nutrients by cytoplasmic streaming.

16) Which of the following pairs are mismatched? 1. arthroconidium - formed by fragmentation 2. sporangiospore - formed within hyphae 3. conidiospore - formed in a chain 4. blastoconidium - formed from a bud 5. chlamydoconidium - formed in a sac

C) 2 and 5

Table 12.1 1-Arthroconidium 5-Chlamydoconidium 2-Ascospore 6-Conidiospore 3-Basidiospore 7-Sporangiospore 4-Blastoconidium 8-Zygospore 7) In Table 12.1, which of these spores are characteristic of Penicillium?

C) 2 and 6

9) In Table 12.1, which is a thick-walled spore formed as a segment within a hypha?

C) 5

36) Which of the following organisms is photoautotrophic protozoan?

C) Euglena

27) A definitive host harbors which stage of a parasite?

C) adult

30) The life cycle of the fish tapeworm is similar to that of the beef tapeworm. Which of the following is the most effective preventive measure to avoid human infection?

C) cooking fish before eating

22) The encysted larva of the beef tapeworm is called a

C) cysticercus.

31) Which of the following is the most effective control for malaria?

C) eliminate Anopheles mosquitoes

18) Helminthic diseases are usually transmitted to humans by

C) gastrointestinal route.

38) Which of the following groups of algae does NOT produce compounds that are toxic to humans?

C) green algae

19) All of the following are characteristic of the Platyhelminthes EXCEPT that they

C) have highly developed digestive and nervous systems.

23) Which of the following arthropods does NOT transmit diseases by sucking blood from a human host?

C) houseflies

41) If a larva of Echinococcus granulosus is found in humans, humans are the

C) intermediate host.

40) Assume you have isolated a multicellular heterotrophic organism that produces coenocytic hyphae, motile zoospores, and cellulose cell walls. It is most likely a(n)

C) oomycote alga.

14) Which of the following tends to be more complex in a parasitic helminth than in free-living helminths?

C) reproductive system

50) The head of a tapeworm intestinal parasite is known as the ________.

C) scolex

2) Which of the following statements about helminths is FALSE?

D) All are parasites.

24) Which of the following statements about algae is FALSE?

D) All are unicellular.

15) Which of the following statements is FALSE?

D) Fungal spores are highly resistant to heat and chemical agents.

3) Which of the following statements about the oomycote algae is FALSE?

D) They have chlorophyll.

28) What do tapeworms eat?

D) intestinal contents

37) Which of the following pairs is mismatched?

D) mosquito - Pneumocystis

25) Below are paired items referring to the heartworm Dirofilaria immitis. Which of the pairs is mismatched?

D) mosquito - definitive host

48) In the roundworms, the females have 1-2 hardened ________ on their posterior ends

D) spicules

44) All of the following are characteristic of lichens EXCEPT

D) they are a symbiotic relationship between a fungus and a protozoan.

8) In Table 12.1, which of these spores are characteristic of Rhizopus?

E) 7 and 8

6) Which of the following pairs is mismatched?

E) anamorphs - lack spores

34) Which of the following pairs is mismatched?

E) cestodes - all are free-living

11) Which of the following pairs is mismatched?

E) coenocytic hyphae - hyphae with cross-walls

17) Which of the following pairs is mismatched? A) dinoflagellates - paralytic shellfish poisoning B) brown algae - algin C) red algae - agar D) diatoms - petroleum E) green algae - prokaryotic

E) green algae - prokaryotic

20) In the malaria parasite life cycle, humans are the ________ host, while mosquitoes are the ________ host as well as the vector.

E) intermediate; definitive

32) In the microscope, you observe multinucleated amoeboid cells with sporangia that form spores. This is a(n)

E) plasmodial slime mold.