Question 1

Which of the following fungi causes Valley fever in semi-arid regions of North American?

Accepted Answer

Coccidioides immitis is the fungus that causes Valley fever, also known as coccidioidomycosis, in semi-arid regions of North America. Blastomyces dermatitidis causes blastomycosis, Cryptococcus neoformans causes cryptococcosis, and Histoplasma capsulatum causes histoplasmosis.

Question 2

Which of the following is not caused by a protozoan?

Accepted Answer

Cryptococcosis is caused by a fungus (Cryptococcus neoformans), not a protozoan. The other options (cryptosporidiosis, African sleeping sickness) are caused by protozoans.

Question 3

Most individuals with histoplasmosis exhibit a hypersensitive state that can be demonstrated by the histoplasmin skin test.

Accepted Answer

Histoplasmin skin test is used to diagnose histoplasmosis and is based on the principle of delayed hypersensitivity. Most individuals with histoplasmosis show a positive reaction to the test, indicating a hypersensitive response to the pathogen.

Question 4

Which of the following is not true with respect to the organism causing histoplasmosis?

Accepted Answer

The mold form of the organism causing histoplasmosis is not found in humans, but rather in the environment where it grows as a filamentous fungus. In humans, it exists as a yeast phase that can grow intracellularly as a facultative parasite. It is found worldwide in soils that contain bird or bat droppings and produces both microconidia and macroconidia as a part of its life cycle.

Question 5

In the malarial life cycle, the male gamete is called

Accepted Answer

The male gamete in the malarial life cycle is called a microgametocyte. The female gamete is called a macrogametocyte. An oocyst is a stage in the life cycle where the zygote develops into a cyst, while an ookinete is a stage where the zygote develops into a motile form.

Question 6

Blastomyces dermatitidis causes

Accepted Answer

Blastomyces dermatitidis causes Blastomycosis, a serious fungal infection that can affect the lungs and other parts of the body.

Question 7

All species of Leishmania utilize sand flies as intermediate hosts.

Accepted Answer

All species of Leishmania require a sand fly as an intermediate host in order to complete their life cycle.

Question 8

Which of the following is known to use tsetse flies as intermediate hosts?

Accepted Answer

Trypanosoma brucei gambiense is known to use tsetse flies as intermediate hosts, while the other options listed do not involve tsetse flies in their life cycle.

Question 9

African sleeping sickness is caused by

Accepted Answer

African sleeping sickness is caused by Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense.

Question 10

Dried pigeon droppings are a potential source of infection with

Accepted Answer

Cryptococcus neoformans is a fungus commonly found in bird droppings, particularly those of pigeons. Exposure to dried pigeon droppings can lead to infection with this organism, which can cause a serious lung infection in humans, especially in those with compromised immune systems. Choice A (Coccidioides immitis) and B (Blastomyces dermatitidis) are not typically associated with bird droppings, while choice D (Malassezia furfur) is a species of yeast that is not commonly found in bird droppings.

Question 11

Vaccines are not effective against trypanosomiasis because

Accepted Answer

Trypanosomes are able to change their surface antigens, or VSGs, by a process called antigenic variation. This allows them to evade the host immune response, rendering vaccines ineffective.

Question 12

In humans, Cryptococcus grows as a

Accepted Answer

Cryptococcus is a yeast form of fungus that causes infections in humans.

Question 13

Once inside an erythrocyte, the Plasmodium begins to enlarge as a uninucleate cell called a __________.

Accepted Answer

Once inside the erythrocyte, Plasmodium enlarges and develops into a trophozoite, which is a uninucleate cell that feeds on hemoglobin.

Question 14

Fungal diseases are usually divided into __________ groups according to the level of infected tissue and the mode of entry into the host.

Accepted Answer

The answer of Fungal diseases are usually divided into __________...

Question 15

Leishmania donovani causes

Accepted Answer

Leishmania donovani causes visceral leishmaniasis, also known as kala-azar. It is a severe form of the disease that affects the internal organs, such as the spleen, liver, and bone marrow. Mucocutaneous leishmaniasis and cutaneous leishmaniasis are caused by other species of Leishmania.

Question 16

Birds carry Histoplasma capsulatum.

Accepted Answer

The answer of Birds carry Histoplasma capsulatum....

Question 17

Most systemic mycoses are acquired from

Accepted Answer

Most systemic mycoses are acquired by inhaling spores, which then germinate in the lungs and become disseminated throughout the body.

Question 18

Some superficial mycoses are called

Accepted Answer

Tineas are a type of superficial mycoses, also known as ringworm, caused by dermatophyte fungi. Sporotrichosis, mycetomas, and dermatophytoses are other types of fungal infections but not specific to superficial mycoses.

Question 19

Diagnosis of the leishmanias is based on finding the parasite within infected

Accepted Answer

The Leishmania parasite resides inside the macrophages of the infected host, making it the primary site for diagnosis.

Question 20

Humans become infected with the malarial parasite when mosquitoes inject __________ into the bloodstream.

Accepted Answer

Humans become infected with the malarial parasite when mosquitoes inject sporozoites into the bloodstream.

Quiz 39: Human Diseases Caused by Fungi and Protists