Question 1

In producing beer and wine, humans have exploited the microbial ability to ferment sugar to alcohol. The microbes responsible for this process are ______.

Accepted Answer

Fungi, specifically yeast, are the microbes responsible for fermenting sugar to alcohol in the production of beer and wine.

Question 2

Plankton are ﬂoating communities of helminths.

Accepted Answer

Plankton are actually microscopic organisms such as algae and protozoa, and not helminths which are parasitic worms.

Question 3

After returning from a trip to Africa, Tom feels tired and weak and has severe anemia. A blood smear reveals a protozoan in his blood and the health care provider diagnoses malaria. Which of the following could be the causative agent of this disease?

Accepted Answer

Malaria is caused by the Plasmodium species of protozoa, with Plasmodium vivax being one of the species responsible for the disease.

Question 4

Infections caused by fungi are called mycoses.

Accepted Answer

Mycoses is the term used to describe infections caused by fungi.

Question 5

Protozoa are classiﬁed into four groups based on ______.

Accepted Answer

Protozoa are classified into four groups based on how they move, which includes flagellates, ciliates, amoebae, and sporozoans.

Question 6

There are no algae that can cause human disease.

Accepted Answer

Some algae, particularly certain types of cyanobacteria (often referred to as blue-green algae), can produce toxins that are harmful to humans, causing diseases or adverse health effects when people are exposed to or consume contaminated water.

Question 7

A specimen from a patient suffering diarrhea shows a one-celled organism in the microscope. The organism moves very slowly by protruding its cytoplasm. You would predict that the patient has an infection caused by ______.

Accepted Answer

Entamoeba, specifically Entamoeba histolytica, is a one-celled organism that moves by extending its cytoplasm in a process known as amoeboid movement, which is consistent with the description given. It is a common cause of amoebic dysentery, which includes symptoms such as diarrhea.

Question 8

All fungi cause some kind of disease in plants or animals.

Accepted Answer

Not all fungi cause disease. Some fungi have beneficial relationships with plants, such as mycorrhizal fungi that help with nutrient absorption, while others have economic uses such as yeasts for bread-making and beer-brewing.

Question 9

During unfavorable growth conditions, many protozoa can convert to a resistant, dormant stage called a/an ______.

Accepted Answer

During unfavorable growth conditions, many protozoa can convert to a resistant, dormant stage called a cyst. This allows them to survive in harsh environments until conditions improve.

Question 10

Amoebic dysentery is most commonly contracted through _______.

Accepted Answer

Amoebic dysentery, caused by the parasite Entamoeba histolytica, is most commonly contracted through the fecal-oral route, which involves the ingestion of food or water that has been contaminated with fecal matter containing the parasite.

Question 11

Protozoan endoplasm contains ______.

Accepted Answer

Endoplasm, the inner region of a protozoan's cell, typically contains cell organelles such as mitochondria, which are responsible for energy production.

Question 12

Protozoan cysts are _______.

Accepted Answer

The answer of Protozoan cysts are _______.
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Question 13

A protozoan cyst differs from a helminth egg in that _______.

Accepted Answer

Cysts can germinate to form the organism directly, while helminth eggs typically need to be fertilized or undergo further development before becoming the mature organism.

Question 14

A protozoan having a ﬂagellum would be classiﬁed in the genus ______.

Accepted Answer

Trypanosoma is a genus of protozoans that possess a flagellum, which is a whip-like structure used for movement.

Question 15

In humans, fungi can only infect the skin.

Accepted Answer

Fungi can infect various organs and tissues in the human body including the lungs, nails, hair, and internal organs. Some examples of fungal infections in humans include athlete's foot, ringworm, candidiasis, aspergillosis, and histoplasmosis.

Question 16

A group of protozoa that are not motile are the ______.

Accepted Answer

Plasmodium species, which are responsible for malaria, are non-motile protozoa during their asexual life cycle stages in humans. Unlike amoebas, ciliates, and certain trophozoites that exhibit motility, Plasmodium sp. rely on host mechanisms for movement and infection dissemination.

Question 17

Which pair is mismatched?

Accepted Answer

Plasmodium causes malaria, not Chagas disease. Chagas disease is caused by Trypanosoma cruzi.

Question 18

Algae are classiﬁed into divisions based principally on their type of motility.

Accepted Answer

Algae are actually classified based on a combination of factors including their photosynthetic pigments, cell wall composition and life cycle. Motility is not the primary determining factor for algae classification.

Question 19

Protozoan cells do not exhibit ______.

Accepted Answer

Protozoan cells are characterized by the absence of a cell wall, distinguishing them from plant and fungal cells which typically have cell walls. Protozoans are a diverse group of unicellular eukaryotic organisms, many of which are motile, can form cysts for protection, exhibit heterotrophic nutrition, and have cellular structures such as ectoplasm and endoplasm.

Question 20

The motile, feeding stage of protozoa is called the ______.

Accepted Answer

The motile, feeding stage of protozoa is referred to as the trophozoite stage. This is when the protozoan is actively feeding and moving.

Quiz 5: Eukaryotic Cells and Microorganisms