Question 1

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

Accepted Answer

Plants appeared after algae, proto-algae, and cyanobacteria, in the evolutionary timeline.

Question 2

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

Accepted Answer

The stumpy form is nondividing and is specialized for survival in the bloodstream of the mammalian host. The slender form is the proliferative form found in the bloodstream, while the procyclic and epimastigote forms are found in the tsetse fly vector and are also actively dividing.

Question 3

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

Accepted Answer

Giardia lamblia lacks mitochondria and therefore cannot perform aerobic cellular respiration. Instead, it uses anaerobic fermentation.

Question 4

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?

Accepted Answer

In the region of Asia where snails commonly ingest trematode eggs, it is likely that free-swimming larvae released by snails in the water could have developed into a secondary form within the fish. Undercooking the fish would not have killed the larvae, resulting in a trematode infection for Rebecca. The other options are less likely as fecal contamination would not be the typical mode of transmission for trematodes, and trematode eggs do not typically develop into larvae within the flesh of fish.

Question 5

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

Accepted Answer

The answer of In the illustrated life cycle of the...

Question 6

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?

Accepted Answer

Acanthamoeba is a common causative agent of amebic keratitis, a serious eye infection that can lead to vision loss. Acanthamoeba is a free-living soil ameba that can contaminate contact lens solutions, leading to infection in those who wear contact lenses. Entamoeba is a genus of protozoa that causes intestinal infections, not amebic keratitis. Babesia is a genus of parasites that causes babesiosis, a disease transmitted by ticks. Toxoplasma is a genus of parasites that causes toxoplasmosis, a disease usually contracted by eating contaminated meat or by exposure to infected cat feces.

Question 7

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?

Accepted Answer

The answer of The image shown indicates two paramecia of...

Question 8

The organism shown in this figure is a(n)

Accepted Answer

The answer of The organism shown in this figure is...

Question 9

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

Accepted Answer

Trypanosoma brucei is carried by tsetse flies, which are found in sub-Saharan Africa. The parasite is transmitted to humans and animals through the bite of an infected tsetse fly.

Question 10

Filamentous amebas

Accepted Answer

The answer of Filamentous amebas
...

Question 11

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

Accepted Answer

The apical complex on a merozoite of Plasmodium falciparum functions as an invasion organelle that allows the merozoite to enter a red blood cell. It is made up of several proteins that aid in the attachment and penetration of the host cell membrane.

Question 12

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

Accepted Answer

Both Giardia lamblia and Trichomonas vaginalis possess flagella, which are whip-like structures that aid in their movement.

Question 13

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

Accepted Answer

Mosquito netting for beds would be the most effective way of stopping transmission of Plasmodium falciparum and P.vivax to humans as these parasites are transmitted to humans through the bite of infected Anopheles mosquitoes during their blood meal. Providing mosquito netting for beds would prevent human-mosquito contact during sleep, thus reducing the risk of transmission. Ensuring access to clean drinking water, checking for ticks after walking in wooded areas, and eliminating bedbugs from sleeping quarters may improve overall health and reduce the risk of other infections, but would not directly address the transmission of malaria.

Question 14

The organism shown is designed for living

Accepted Answer

The organism shown appears to have flagella and a cell wall, which are characteristics of bacteria that typically live on the outer surface of the body. It is unlikely to be living within the small intestine, red blood cells, or on the outer surface of the liver.

Question 15

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

Accepted Answer

The answer of What is the function of the process...

Question 16

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

Accepted Answer

Amoeba proteus moves by cytoplasmic streaming, which is the movement of cytoplasm within the cell, causing the pseudopods to extend or retract and allowing the amoeba to move in a specific direction. The amoeba does not have flagella, cilia, or needle-like pseudopods.

Question 17

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

Accepted Answer

Mites, ticks, and lice are all ectoparasites, which means they live and feed on the external surface of their host. They are not insects but belong to different classes of arthropods. While some species of ticks and lice can transmit disease agents, it is not a characteristic shared by all of them. Depositing eggs within the skin is also not a universal trait among mites, ticks, and lice, although some species of lice do attach their eggs to individual hairs.

Question 18

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?

Accepted Answer

A Wheatley's trichrome stain is used specifically to identify protozoa, including the causative agent of amebic dysentery, Entamoeba histolytica. It would show the presence of a protozoa with ingested red blood cells. Immunological tests or Gram stains are not specific to revealing amebic infections, and endospore stains are not relevant in this case as amebas do not form endospores.

Question 19

Which of the following is unique to ciliates?

Accepted Answer

Ciliates are unique in maintaining two types of nuclei within their cells: a macronucleus for general cell function and a micronucleus for reproduction. While cilia, endocytosis, and microtubules are all present in various other types of cells, the maintenance of two nuclei is specific to ciliates.

Question 20

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

Accepted Answer

Perianal itching is a common symptom of a pinworm infection. When an infected individual scratches their anus, they may transfer pinworm eggs that are present under their fingernails to new hosts, leading to the continuation of the pinworm life cycle.

Quiz 11: Eukaryotic Microbes and Invertebrate Infectious Agents