A. Yeast have cellulose cell walls, while mold has chitin cell walls.
B. Yeast is colonial, while mold is multicellular.
C. Yeast is unicellular, while mold is multicellular.
D. Yeast is a fungus, while mold is an alga.
A. Inject the organism into a lab animal. If it does not cause disease, it is an alga.
B. Determine if the organism is unicellular by microscopy. If it is unicellular, it is an alga.
C. Perform a biochemical test for the presence of chitin.
D. Place the sample in a clear container filled with media containing no sugars, and leave it in a sunny window. After a few weeks, look for growth of the organism.
A. a chemical that inhibits the Krebs cycle
B. a chemical that inhibits formation of the membrane around the nucleus
C. a chemical that inhibits the formation of cell walls
D. a chemical that inhibits cell division
Apicomplexa contains many species that cause disease, including the Plasmodium species that cause Malaria.
A. Amoebozoa
B. ciliates
C. Apicomplexa
D. Euglenozoa
A. mites and ticks
B. fleas
C. mosquitoes
D. sucking lice
A. Karyogamy refers to a part of the sexual reproduction cycle in which two haploid nuclei fuse to form a diploid zygote.
B. Conidiospores are spores that are enclosed in a specialized sac-like structure.
C. Most fungi reproduce only asexually.
D. Fungi are usually identified using biochemical tests.
Dinoflagellates are a type of unicellular algae. During red tide, high levels of a neurotoxin produced by Alexandrium (a dinoflagellate) are found in shellfish. Consumption of these shellfish leads to a foodborne disease called paralytic shellfish poisoning.
A. protozoa; dysentery
B. algae; paralytic shellfish poisoning (PSP)
C. fungus; potato blight
D. tapeworm; cysticercosis
A. When conditions become harsh, some protozoa can form a protective capsule, which is called a cyst.
B. Some protozoa reproduce by schizogony, a process that is virtually identical to the budding process that happens in some yeast.
C. Most protozoa are photosynthetic.
D. All protozoa can undergo sexual reproduction.
A. They are always dioecious, which means that one individual has both male and female reproductive organs.
B. Helminths usually possess specialized organ systems, including circulatory, nervous, and reproductive systems.
C. They are unicellular.
D. The life cycle of helminths is always very simple, and they usually infect only one host.
A. It has an undulating membrane, infects the vagina, and is frequently transmitted by sexual contact.
B. It is usually found in drinking water and is associated with fecal contamination.
C. It is a photosynthetic organism that lives in fresh water.
D. It infects Anopheles mosquitoes and can be transmitted by a bite.
A. Taenia solium; roundworm
B. Echinococcus granulosus; tapeworm
C. Plasmodium; cestode
D. Taenia saginata; tapeworm
The life cycle of Plasmodium species requires two hosts, one of which is a mosquito.
A. Necator americanus
B. Ascaris lumbricoides
C. Enterobius vermicularis
D. Plasmodium species
Dermatophytes (Greek for “skin plants”) is a common label for a group of three types of fungi that cause skin disease in humans and other animals.
A. cutaneous mycoses
B. systemic mycoses
C. opportunistic infections
D. subcutaneous mycoses
A. gram-negative bacterium.
B. dimorphic fungus.
C. parasitic alga.
D. yeast.
E. protozoan.
A. nematode.
B. fungus.
C. protozoan.
D. cestode.
E. trematode.
A. Candida albicans.
B. Aspergillus.
C. Penicillium.
D. Histoplasma.
E. Saccharomyces cerevisiae.
A. The fungal partner provides a means of attachment and protects the algal partner from desiccation.
B. Lichens are very tolerant to pollution.
C. Lichens represent a mutualistic relationship between a fungus and an alga.
D. The algal partner produces carbohydrates that are absorbed by the fungal partner.
E. Lichens are often the first life form to colonize rock or soil.
A. They produce oxygen from hydrolysis of water.
B. They use CO2 as their carbon source.
C. Some are capable of sexual reproduction.
D. All are unicellular.
E. They use light as their energy source.
A. most are photoautotrophs.
B. some produce harmful toxins.
C. they may be unicellular or multicellular.
D. they mostly live in aquatic habitats.
E. they are classified as plants.
True
False
A. lack nuclei.
B. are motile.
C. lack mitochondria.
D. do not produce cysts.
E. do produce cysts.
A. eliminate the intermediate host
B. vaccination
C. treating patients
D. eliminate Anopheles
E. None of these is an effective control.
A. Giardia
B. Cryptosporidium
C. diatoms
D. Entamoeba
E. Taenia
A. Euglenozoa.
B. cellular slime mold.
C. plasmodial slime mold.
D. tapeworm.
E. ascomycete.
A. they form spores.
B. they distribute nutrients by cytoplasmic streaming.
C. they have a mouth to ingest nutrients.
D. they have organelles.
E. the large surface can absorb nutrients.
True
False
A. They are heterotrophic.
B. Some have male and female reproductive organs in one animal.
C. They are multicellular animals.
D. All are parasites.
E. They have eukaryotic cells.
A. digestive system
B. nervous system
C. reproductive system
D. digestive and nervous systems
E. digestive, reproductive, and nervous systems
A. aerosols.
B. respiratory route.
C. gastrointestinal route.
D. vectors.
E. genitourinary route.
A. humans are the definitive host and crayfish are the intermediate host.
B. both humans and crayfish are definitive hosts.
C. the crayfish are the definitive host and humans are the intermediate host.
D. the source of the infection was the river water.
both humans and crayfish are intermediate hosts.
A. redia.
B. metacercaria.
C. cercaria.
D. cysticercus.
E. proglottid.
A. cyst
B. larva
C. miracidium
D. adult
E. All of the answers are correct.
A. host tissues
B. plant matter
C. intestinal bacteria
D. intestinal contents
E. red blood cells
A. dog – sexual reproduction
B. dog – definitive host
C. mosquito – vector
D. mosquito – definitive host
E. None of the pairs is mismatched.
A. wearing gloves while handling fish
B. not swimming in fish-infested waters
C. refrigerating stored fish
D. cooking fish before eating
E. salting fish before eating
A. definitive host.
B. infected host.
C. reservoir.
D. intermediate host.
E. None of the answers is correct.
True
False
True
False
True
False
A. humans are the intermediate host.
B. mosquitoes are the definitive host.
C. mosquitoes are the vector.
D. humans are the intermediate host and mosquitos are the definitive host.
E. humans are the intermediate host and mosquitoes are both the definitive host and the vector.
A. fleas
B. houseflies
C. mosquitoes
D. kissing bugs
E. lice
True
False
Diagnosis of a yeast infection usually involves patient history, observation of yeast cells via microscopy, and growth of a culture on Sabouraud dextrose agar. Differentiation between yeasts and bacteria is reliant on biochemical characteristics. Differentiation between yeasts and molds is reliant on spore type and function.
A. Gardnerella vaginalis
B. Trichomonas vaginalis
C. Sporothrix schenckii
D. Candida albicans
Tori had undergone treatment with a broad-spectrum antibiotic for her respiratory infection. Antibiotic treatment most likely affected the normal flora in the vagina, resulting in a preferential decrease in bacterial numbers. Yeasts are normal flora in the vagina, but with fewer bacteria present to antagonize their growth, the yeast cells were allowed to flourish beyond their normal levels. The increased numbers of yeast cells led to Tori’s new symptoms. She had developed a yeast infection as a secondary infection to her primary respiratory infection. A secondary infection is defined as an infection caused by an opportunistic microbe after a primary infection has weakened the host’s defenses. Yeast infections are common secondary infections after antibiotic treatment for a primary bacterial infection.
A. The antibiotics that treated Tori’s primary respiratory infection also removed some of her normal bacterial flora, resulting in an overgrowth of other organisms.
B. Tori’s immune system was compromised because of her respiratory infection, and this resulted in a yeast infection.
C. The initial antibiotics were not successful in clearing the respiratory infection, so the organism disseminated to the genitourinary tract.
D. Tori contracted a sexually transmitted infection that was not related to the primary respiratory infection.
– a topical over-the-counter ointment, such as clotrimazole or miconazole
Treatment of a yeast infection includes the application of topical ointments and the use of oral antifungal agents. Nonprescription antifungal creams are among the most commonly purchased over-the-counter medications in the United States.
Select all that apply.
– a single oral dose of fluconazole
– an antiviral medication, such as acyclovir
– a topical over-the-counter ointment, such as clotrimazole or miconazole
– an oral narrow-spectrum antibiotic, such as penicillin G
– fulminating disease
Candida albicans is also the causative agent of oral thrush and fulminating disease. Infants are prone to thrush because they come in contact with the yeast as part of mom’s normal flora when nursing. Fulminating disease, which most often afflicts immunosuppressed individuals, results when the yeast enters the bloodstream and travels throughout the entire body, resulting in a systemic infection. Individuals suffering from AIDS are susceptible to this type of infection.
Select all that apply.
– genital warts
– oral thrush
– fulminating disease
– syphilis
One of the key similarities between a fungus and its human host is that both are eukaryotic. This makes it difficult to develop antifungal drugs, because therapeutic agents that target certain properties of the fungus (e.g., ergosterol in the membrane, DNA replication, protein synthesis) also have the potential to target the host cells. One of the keys to antimicrobial therapy is selective toxicity, which means that the agent will hinder/kill the pathogen without doing much damage to the host. The more similar the agent is to its host, the harder it is to achieve selective toxicity.
A. Fungal cells and human cells have a nucleus, multiple organelles, and 80S ribosomes for protein synthesis.
B. Fungal cells and human host cells both have cell walls made of cellulose.
C. Fungal cells and human cells both reproduce via budding.
D. Fungal cells and human host cells both have flagella for movement.
Blastoconidia and chlamydoconidia are asexual spores used for reproduction. Blastoconidia and chlamydoconidia produce cells that are identical to the parent cells, whereas sexual spores produce offspring that have characteristics of both parents. Endospores are produced by bacteria during harsh conditions.
A. Blastoconidida and chlamydoconidia are identical to endospores.
B. Blastoconidia and chlamydoconidia are spore structures produced by budding in yeasts, whereas bacterial endospores are produced by bacteria under extreme conditions.
C. Blastoconidia and chlamydoconidia are produced only by yeasts in extreme conditions, whereas bacterial endospores are asexual reproductive structures.
D. Blastoconidia and chlamydoconidia are male and female mating structures used for reproduction in yeasts, whereas bacterial endospores are asexual reproductive structures.
Yeasts use the pseudohyphae as a virulence factor to better penetrate the host’s tissues and also to evade phagocytosis. Filamentous fungi use their vegetative hyphae as a means to absorb nutrients from their environment. In optimal conditions, the vegetative hyphae will grow into a substrate to obtain food and will then support the growth of aerial hyphae, which project above the surface of the medium. These aerial hyphae are responsible for producing the reproductive spores of the fungus.
A. Yeasts use pseudohyphae for obtaining nutrients, whereas filamentous fungi use their vegetative hyphae to invade host tissues.
B. Yeasts use pseudohyphae as a means of obtaining nutrients, whereas filamentous fungi use vegetative hyphae as a means of reproduction.
C. Yeasts use pseudohyphae to invade host tissue, whereas filamentous fungi use their vegetative hyphae for obtaining nutrients.
D. Yeasts use pseudohyphae as a means of sexual reproduction, whereas parasitic fungi use their hyphae to invade host tissue.