Unit V

Question 1

What percentage of known species are thought to be parasitic?

Answer 1

At least 50% of all known species are parasitic.

Question 2

How many different parasites can the human body host?

Answer 2

Over 350 different parasites.

Question 3

What are the two major categories of human parasites?

Answer 3

Protozoa (unicellular) and Helminths (multicellular worms).

Question 4

Are protozoa unicellular or multicellular?

Answer 4

Unicellular.

Question 5

Are helminths unicellular or multicellular?

Answer 5

Multicellular.

Question 6

Name the four major protozoan groups with examples.

Answer 6

Amoeboid (Amoeba), Ciliated (Balantidium), Flagellated (Giardia, Trypanosoma), Apicomplexan (Plasmodium, Toxoplasma).

Question 7

Name the three major helminth groups.

Answer 7

Nematodes (roundworms), Trematodes (flukes), Cestodes (tapeworms).

Question 8

What are the four main components of a parasite transmission cycle?

Answer 8

Infected human, parasite shed from body, infective stage, animal host or arthropod vector.

Question 9

What type of parasite is Toxoplasma gondii?

Answer 9

An apicomplexan protozoan.

Question 10

What structure allows Toxoplasma to invade host cells?

Answer 10

The apical complex.

Question 11

Who is the definitive host of Toxoplasma gondii?

Answer 11

Cats.

Question 12

What is the infective (sexual) stage of Toxoplasma shed by cats?

Answer 12

Oocysts.

Question 13

How do humans commonly acquire Toxoplasma infection?

Answer 13

Ingesting sporulated oocysts from contaminated food/water or ingesting infected undercooked meat.

Question 14

Which form of Toxoplasma rapidly replicates in human tissues?

Answer 14

Asexual Tachyzoites.

Question 15

Which form of Toxoplasma crosses the placenta?

Answer 15

Tachyzoites.

Question 16

What does STORCH represent?

Answer 16

A group of congenital infections: Syphilis, Toxoplasma, Other, Rubella, CMV, Herpes.

Question 17

What lab method can confirm Toxoplasma infection by detecting parasite DNA?

Answer 17

PCR.

Question 18

Why did antibiotics fail in the toxoplasmosis case study?

Answer 18

Because the infection was parasitic, not bacterial.

Question 19

What was unusual about the pneumonic toxoplasmosis case?

Answer 19

It occurred in an immunocompetent person.

Question 20

What are oocysts primarily responsible for in Toxoplasma infection?

Answer 20

Environmental transmission.

Question 21

What are tachyzoites primarily responsible for in Toxoplasma infection?

Answer 21

Acute tissue invasion and dissemination.

Question 22

Which stage is environmentally resistant in Toxoplasma?

Answer 22

Oocysts.

Question 23

Which stage is associated with acute disease symptoms in Toxoplasma?

Answer 23

Tachyzoites.

Question 24

What type of parasite is Taenia solium?

Answer 24

A cestode (tapeworm).

Question 25

What disease results from eating undercooked pork containing cysticerci?

Answer 25

Taeniasis.

Question 26

What disease results from ingesting Taenia solium eggs?

Answer 26

Cysticercosis.

Question 27

Where does taeniasis occur in the body?

Answer 27

In the intestine.

Question 28

Where does cysticercosis occur in the body?

Answer 28

In tissues (brain, muscle, eyes).

Question 29

In taeniasis, when is the human a definitive or intermediate host?

Answer 29

Definitive host after eating undercooked infected meat and adult cestode in intestines intermediate host when ingested eggs leading to larval cycsts in tissues

Question 30

In cysticercosis, is the human the definitive or intermediate host?

Answer 30

Accidental intermediate host.

Question 31

Which condition is more dangerous: taeniasis or cysticercosis?

Answer 31

Cysticercosis.

Question 32

What are proglottids?

Answer 32

Segments of a tapeworm that contain eggs.

Question 33

What are cysticerci?

Answer 33

Larval cyst forms of Taenia found in meat.

Question 34

Which form is ingested to cause taeniasis: eggs or cysticerci?

Answer 34

Cysticerci.

Question 35

Which form is ingested to cause cysticercosis: eggs or cysticerci?

Answer 35

Eggs.

Question 36

Define zoonotic infection.

Answer 36

An infection transmitted from animals to humans.

Question 37

What is the key difference between a definitive and intermediate host?

Answer 37

Sexual reproduction occurs in the definitive host; asexual development occurs in the intermediate host.

Question 38

Why is understanding parasite life cycles critical in medicine?

Answer 38

It explains transmission, symptoms, diagnosis, and treatment.

Question 39

Which helminth group are roundworms?

Answer 39

Nematodes.

Question 40

Which helminth group are flukes?

Answer 40

Trematodes.

Question 41

Which helminth group are tapeworms?

Answer 41

Cestodes.

Question 42

Which protozoan group includes Plasmodium and Toxoplasma?

Answer 42

Apicomplexans.

Question 43

What is the major role of tachyzoites in congenital infection?

Answer 43

They cross the placenta and infect the fetus.

Question 44

What stage of Taenia solium is found in stool that may resemble “tuna fish”?

Answer 44

Proglottids.

Question 45

what is the best way to preserve and protect against microbes

Answer 45

Moist heat under pressure