Unit U: Parasitology

Unit U: Background Information

Unit U: Parasitology

Reading Integration:

Complete the Pre- and Post-Vocabulary Assessment.


Stump the Teacher: Students and the instructor should read about parasitology

to themselves. Next, students should try to think of questions to try to stump the

instructor. Their questions should be about the content and not along the lines of

“What is the fourth word on page 2?”

Background Information

Parasites are one of the most prolific types of organisms in the world. A parasite is

an organism that lives within or on another organism. The organism that the parasite lives

off of is called the host, and the parasite is dependent on its host. The parasite may harm

the host organism but usually does not kill it. This is a type of symbiotic relationship.

Parasites can include many types of organisms: animals, viruses, bacteria, fungi and plants.

Parasites can infect every living thing on earth, including other parasites. They can cause

significant harm to animals and humans by spreading zoonotic and vector-borne diseases.

Parasites can cause economic losses in the livestock industry, including decreased efficiency,

increased time to market weight, and decreased carcass value.

Kinds of Parasites

Parasites are classified as endoparasites, living inside the animal, or ectoparasites,

living outside the animal. Endoparasites can produce an infection within the host animal and

cause damage by absorbing food intended for the host, drawing blood and lymph fluid,

damaging tissue and causing internal bleeding, creating obstructions in the intestines and

circulatory system, and producing toxins. Ectoparasites produce an infestation on the host

animal that can cause irritation to the skin, restlessness and worry, the transmission of

infectious organisms, and the drawing out of blood.

Parasites can also be classified by their physical characteristics and scientific name.

There are only two kingdoms that have organisms that are true parasites of domestic

animals -- Kingdom Animalia (platyhelminths, nematodes, acanthocephalans, annelids and

arthropods) and Kingdom Protista (protozoans).

Background Background


Endoparasites come from both Kingdom Animalia and Kingdom Protista. Common

endoparasites are roundworms, flatworms, thorny-headed worms, tapeworms and protozoa.

Ectoparasites come only from Kingdom Animalia. Common ectoparasites include mites, ticks,

mosquitoes and flies.

A dichotomous key is a tool used to identify plants or animals through a set of

characteristics. It is also helpful in identifying parasites according to their characteristics.

Each step in the key has two distinct options and directs the user to a new step until the

object is identified. This is a useful tool for scientists, veterinary staff or producers to identify

a parasite that they do not know. It is important to properly identify the parasite, so that the

animal can be treated effectively.

Life Cycles of Parasites

A parasite matures through a set of stages throughout its life, and every parasite has

its own unique life cycle. All parasites have a definitive host, and some parasites may have

more than one definitive host. Many also have an intermediate host or hosts. An

intermediate host can be classified as a paratenic, or transport host, if the parasite is

dormant within that host. The parasite becomes active again only when its definitive host

eats the paratenic host. A parasite that only has a definitive host is said to have a direct life

cycle. A parasite that has one or more intermediate hosts has an indirect life cycle.

Most ectoparasites go through metamorphosis, a series of changes throughout their

life cycles. Some species go through complete metamorphosis which has four stages:

Egg

Larvae

Pupa

Adult.

Other species go through incomplete metamorphosis, which has three stages:

Egg

Nymph

Adult.

Endoparasites also have immature and adult stages to their life cycle. Most

endoparasites develop partially outside of the definitive host before they infect it. There are

four major ways that internal parasites infect definitive hosts:

1) direct ingestion

2) eating an intermediate host

Background


3) penetrating the definitive host

4) maternal transmission.

Controlling Parasites

It is important to have a good understanding of parasite life cycles because some

parasites can only be treated in certain stages of their life cycles with certain specific

treatments. Other parasites are only treated effectively by removing an intermediate host.

Many parasites are specific to one type of animal and are considered homoxenous.

Parasites adapt to be able to affect a specific host. The host and the parasite often evolve

together. The host may develop immunity or adaptations to evade the parasite. In turn, the

parasite will then develop new mechanisms to affect the host. Parasites also have strategies

to evade a host’s defense mechanisms. The host of a parasite that only occasionally affects

another species of animal is called an incidental host.

There are many factors that affect how host specific a parasite is. These include the

following:

The host must share the same environment as the parasite.

The host must be exposed to the parasite as part of its normal behavior.

The host must be recognized by the parasite via secretions, surfaces or

membranes.

The host must be able to meet nutritional requirements of the parasite.

Within a particular host species, a parasite may also have a preferred type of

organism with which it establishes a relationship. Young and old animals; pregnant and

lactating animals; malnourished, stressed or immune-compromised animals are more

susceptible to parasites, due to immature or weakened immune systems. Host animals that

are resistant to the parasite help to strengthen the genetics of the host population.

Just as parasites can be host specific and impact a certain species of animal, they can

also be regionally specific and thrive in a certain environment. A parasite creates a niche or

place in its ecosystem where it can obtain resources and survive. A parasite is considered

endemic if it is continually found within a population of animals in a specific region.

Enzootic is another term for this phenomenon.

There are many reasons why parasites are often limited to certain regions. The

parasite has to be able to complete its life cycle in a certain environment. Parasites may be

able to survive inside of a host or on a host in a particular environment, but if the

Background


conditions are not right for the parasite to complete the part of its life cycle that is not on

or in a host, it will not be able to survive in that environment. Prevalence of parasites in any

given region is dependent on the presence of definitive and intermediate hosts, weather

conditions and climate.

Transmitting Parasites

A vector is a living organism that carries a parasite and transmits it to another

organism. A vector can be strictly mechanical and just transmit the parasite, or if it serves as

a true intermediate host, it may be a necessary part of the parasite’s life cycle. A vehicle is a

non-living thing that spreads a parasite. Ectoparasites serve as vectors for many other

parasites, bacteria, viruses and fungi. Common vehicles that spread parasites include food,

water, feces and blood. Another type of vehicle is called a fomite. A fomite is an inanimate

object that a parasite can live on until it is picked up by a host. Even clothing and bedding

that may be contaminated with infectious organisms can serve as fomites in the

transmission of parasites.

Internal parasites often need some sort of vector or vehicle within their life cycle to

spread their infective stage to new hosts. The adult stage of the internal parasite does not

typically survive outside of the host. One strategy that is used by parasites is transmission in

a predator-prey situation. The parasite is released into the environment and ingested by a

prey animal that is a herbivore. This prey animal is a reservoir host or an intermediate host.

When the predator eats a prey animal that is infected, the parasite is transferred to the

definitive host.

An additional way that a vector can transmit a parasite is through blood contact.

When an animal, such as a mosquito, feeds on blood, it becomes an intermediate host and

transmits a parasite from one host to the next. Sometimes the parasite can live inside this

intermediate host for a period of time before being transmitted to the next definitive host.


Complete the Inquiry Chart about parasites.

1. Reference the Inquiry Chart found at the end of Background Information.

Students will be given sources or instructed to research them.

a. There are questions in columns across the top.

b. Each row corresponds with a particular source.

c. The last row is a general summary of each question.

Background


2. After reading the Critical Questions in the header row, students should assess

what they already know about each question.

3. Then students explore the topics through questions in the columns. For each

source or text, they answer questions based on the source or text.

4. At the bottom, students compile all they have discovered into a coherent

summary statement to answer each question for the topic in general.

Controlling Parasites

Animals are treated with antiparasitic drugs to control parasite infections and

infestations. Antiparasitic resistance is the ability of parasites to survive a treatment of an

antiparasitic drug to which they had been susceptible in the past. This ability is genetic and

can be a problem when a large percentage of parasites affecting the animal carry the

resistant gene. These parasites can then survive a treatment that was previously effective.

When an animal is treated with antiparasitic drugs, a certain percentage of the

parasites will survive the treatment because they are genetically resistant to the drug. The

resistant parasites then breed with each other and pass on those resistant genes to their

offspring. If there are not a lot of susceptible parasites left, then the population will become

more resistant and will no longer respond to the antiparasitic drug.

When animals are treated for parasites, there is a certain percentage of the

population of that parasite that is not affected. This could be parasites that are living in or

on untreated animals, eggs and larva that are in the environment, or life stages of the

parasite that are not affected by the treatment drug. These parasites are called refugia or

parasites that are not selected for treatment. These unaffected parasites have not developed

resistance, because they were not exposed to the antiparasitic drug.

There are many things that increase antiparasitic resistance. The genetics of the

parasite, how it lives, and its pathogenicity can increase resistance. The immune status of the

host, frequency of treatment, mechanism of action of the drug, and overall animal

management factors can also have an effect.

Internal parasites often have to be identified by examining a fecal sample using a

microscope. There are several methods for preparing a fecal sample for diagnosis. They

include the following:

Direct smear, in which a small amount of feces is placed on a slide and examined

under a microscope

Background


Fecal flotation, a procedure that uses specific gravity to allow parasite eggs, cysts,

and larvae to float to the top of a solution

Fecal sedimentation, which separates out parasite eggs that have so high a

specific gravity that it would be difficult to make them float.

Blood samples and skin scraping can also serve as diagnostic tools.

Parasites have a symbiotic relationship with their hosts. These species have co-

evolved over time and the hosts must develop new strategies to prevent the parasites from

impacting them. Parasites must get past the host’s defense systems in order to be able to

feed. Each time a new host defense strategy evolves, the parasite develops a strategy to

counter it. Over time these animals have developed a complex relationship of attack and

defense mechanisms.

Innate defenses are host defenses that naturally occur and prevent any harmful

organism from entering their systems. Hosts have a large variety of innate defenses that are

utilized to protect themselves against parasites and keep parasite levels in check. These

include the following:

Beneficial bacteria

Low pH is specific areas of the body (i.e. stomach)

Enzymes in saliva

Peristalsis in the intestines that keep substances constantly moving

Keratin, a protein particle in skin, that prevents parasites from entering

Sebum, produced by sebaceous glands and is toxic to some invaders

Mucus membranes

Macrophages, cells in the lungs that engulf and destroy microorganisms

It is acceptable for some animals to have a small number of parasites or worms living

in their body symbiotically. However, if the defenses of an animal’s body are worn down, or

if the animal is immune compromised or unhealthy for any reason, a parasite may increase

in numbers. If the parasite load becomes too high, the animal will begin to show negative

effects of the parasite invasion. Treatment to eliminate or reduce the parasite load should

occur immediately if parasites are negatively impacting the animal.

Background


Name_____________________________________

Pre/Post Vocabulary Assessment for Parasitology

For each term listed below, first complete the “Pre” column. If you have never heard of the

word or concept, write a – (minus) in the column. If you have heard of the word or concept,

write a (check) in the column. If you have heard of the word or concept and could carry

on a quasi-expert conversation using it, write a + (plus) in the column.

Pre Term Post

Parasite

Host

Zoonotic disease

Endoparasite

Ectoparasite

Metamorphosis

Homoxenous

Vector

After the lesson, you will reassess your knowledge of these important terms related to

parasitology by using the same marking system. This time, mark the “Post” column.

Background


Name_____________________________________

Parasites Inquiry Chart Critical Question #1:

What are some of the best

methods of controlling

parasites?

Critical Question #2:

When is the appropriate

time to apply medicine to

control parasites?

Critical Question #3:

What is the role of

sanitation in parasite

control?

What I think

I know

Source #1

Source #2

Source #3

Summary of

Information

Background

Unit U: Answer Keys

Unit U Answer Keys:

Lesson Post-test Answers

U.1.1 1. C 2. B 3. A 4. D 5. A

Answer Keys

U.1.1: Instructor

U.1.1 Parasite Sleuth

Pre-Lesson Preparation:

U.1.1 PowerPoint® Presentation: Parasite Identification (Blank-NOT the Answer

Key) needs to be printed in color for students to utilize. Slides can be cut into cards

or used full size. Students may complete this on a computer to save paper.

Materials:

U.1.1 Student Activity Directions

U.1.1 Student Handout 1: PowerPoint® Notes: Parasite Identification

U.1.1 Student Handout 2: Endoparasite Dichotomous Key

U.1.1 Student Handout 3: Ectoparasite Dichotomous Key

U.1.1 Student Handout 4: Parasite Sleuth

U.1.1 Evaluation: Parasite Sleuth

U.1.1 Post-test Questions: Parasite Sleuth

U.1.1 PowerPoint® Presentation: Parasite Identification

*This item needs to be printed in color for students to utilize. Slides can be cut into

cards or used full size. Additionally, students may complete this on a computer to

save paper and colored ink.

U.1.1 PowerPoint® Presentation: Parasite Identification Answer Key

Pencil one per student

Goals:

Skill: Use a dichotomous key to identify parasites.

Content: Identify common parasites of animals.

Terminology:

Classification: the organization of things based upon shared characteristics

Key Point:

Parasites can be identified by their physical

characteristics.

Instructor

U.1.1: Instructor

Dichotomous key: a tool for identification that involves a series of choices a user

works through until the object is identified

Ectoparasite: a parasite that lives on the outside of a host

Endoparasite: a parasite that lives within a host

Host: an organism that a parasite is dependent on; a plant or animal that a parasitic

or commensal organism lives on or in; an organism that provides nourishment

and/or shelter for a parasite

Parasite: an organism that lives in or on another organism and benefits at the

expense of the host organism

Parasite infection: disease caused by protozoan parasites

Parasite infestation: disease caused by arthropods and worms

Taxonomy: the science of classifying organisms

Zoonotic: describing a disease that can be passed from animals to humans

Question to Consider:

What traits are used to help differentiate parasites from one another?

Procedure:

1. The instructor will present the Question to Consider for writing or discussion.

2. Direct students to U.1.1 Student Handout 1: PowerPoint® Notes: Parasite

Identification.

3. The instructor will present U.1.1 PowerPoint®: Parasite Identification while students

follow along and complete U.1.1 Student Handout 1: PowerPoint® Notes: Parasite

Identification.

4. Direct students to U.1.1 Student Handout 2: Endoparasite Dichotomous Key, U.1.1

Student Handout 3: Ectoparasite Dichotomous Key, and U.1.1 Student Handout 4:

Parasite Sleuth.

Instructor

U.1.1: Instructor

5. Students should work in pairs to complete the U.1.1 Student Handout 4: Parasite

Sleuth activity. Each pair should be given a set of U.1.1 Parasite Identification slides

or cards that have been printed or copied ahead of time (U.1.1 PowerPoint®:

Parasite Identification cards printed from slides.)

6. Instructor will utilize U.1.1 PowerPoint® Presentation: Parasite Identification Answer

Key to review answers.

Assessments:


U.1.1 Post-test Questions: Parasite Sleuth

Additional Resources:

Local veterinary offices may have preserved parasite specimens for students to

view and identify. Specimen slides or mounts for endoparasites and ectoparasites

may also be purchased from Ward’s Science or another science supply company and

utilized in place of the pictures.

An extension to the above activity would be to allow students to create their

own dichotomous keys for parasites.

For additional information, see Laboratory Identification of Parasitic Diseases

of Public Health Concern at http://www.cdc.gov/dpdx/az.html

References:

Hendrix, C. M. (1998). Diagnostic Veterinary Parasitology. St. Louis, MO: Mosby Inc.

National FFA Organization. (2013). Veterinary Science Career Development Event

Manual. Retrieved from

https://www.ffa.org/SiteCollectionDocuments/cde_vetscience.pdf

Parasites of Dogs, Cats, Horses and Livestock: Biology and Control. (n.d.). Retrieved

Sept. & Oct., 2016, from http://parasitipedia.net/index.php?option=com_

content &view=article&id=2391&Itemid=2654

Instructor

http://www.cdc.gov/dpdx/az.html

https://www.ffa.org/SiteCollectionDocuments/cde_vetscience.pdf

http://parasitipedia.net/index.php?option=com_

U.1.1: Student Activity

U.1.1 Student Activity: Parasite Sleuth

Purpose:

Parasites affect all types of animals, and they are found all over the world.

Identifying parasites is the first step to controlling them. A dichotomous key is a

helpful tool in identifying common parasites of domestic animals.

Know and Do:

Use a dichotomous key to identify parasites.

Identify common parasites of animals.

Terminology:

Classification: the organization of things based upon shared characteristics

Dichotomous key: a tool for identification that involves a series of choices a user

works through until the object is identified

Ectoparasite: a parasite that lives on the outside of a host

Endoparasite: a parasite that lives within a host

Host: an organism that a parasite is dependent on; a plant or animal that a parasitic

or commensal organism lives on or in; an organism that provides nourishment

and/or shelter for a parasite

Parasite: an organism that lives in or on another organism and benefits at the

expense of the host organism

Parasite infection: disease caused by protozoan parasites

Parasite infestation: disease caused by arthropods and worms

Taxonomy: the science of classifying organisms

Zoonotic: describing a disease that can be passed from animals to humans

Student

Key Point:

Parasites can be identified by their physical

characteristics.

U.1.1: Student Activity Directions

Materials:

U.1.1 PowerPoint® Presentation: Parasite Identification (cards or sheets)

U.1.1 Student Activity Directions

U.1.1 Student Handout 1: PowerPoint® Notes: Parasite Identification

U.1.1 Student Handout 2: Endoparasite Dichotomous Key

U.1.1 Student Handout 3: Ectoparasite Dichotomous Key

U.1.1 Student Handout 4: Parasite Sleuth


Pencil (– one per student)

Procedure:

1. Respond to the Question to Consider as directed by your instructor.

2. Follow along and fill in U.1.1 Student Handout 1: PowerPoint® Notes using

U.1.1 PowerPoint® Presentation: Parasite Identification and PowerPoint®: Parasite

Identification cards or sheets from the slide presentation.

3. The instructor will break students into pairs. Complete the Parasite Sleuth activity

on U.1.1 Student Handout 4: Parasite Sleuth together. You will also need U.1.1

Student Handout 2: Endoparasite Dichotomous Key and U.1.1 Student Handout 3:

Ectoparasite Dichotomous Key.

5. Utilize U.1.1 Student Handout 4: Parasite Sleuth to record your results. The

instructor will provide you with parasite ID slides or cards to identify the parasites.

6. Review the correct identification of the parasites with your instructor utilizing the

PowerPoint®: Parasite Identification Answer Key.

7. Complete U.1.1 Evaluation: Parasite Sleuth if requested by your instructor.

Student

U.1.1: Student Handout 1

U.1.1 Student Handout 1: PowerPoint® Notes

Parasite Sleuth Symbiotic Relationships:

Predator-Prey:

Mutualism:

Commensalism:

Parasitism:

Parasite Scope:

Any living thing can be infected by a ______________, including other _______________.

Parasites are one of the most prolific types of organisms in the world.

Parasites cause huge economic losses to ____________ _____________ each year.

Parasites spread ______________ ______________

Classification: Endoparasites: Exoparasites:

Examples:

Damage: 1)

2)

3)

4)

1)

2)

3)

4)

Student


Classification of Parasites

Common Name versus Scientific Name

Carl Linnaeus

D______________

K_______________

P________________

C________________

O_______________

F________________

G________________

S________________

Classification of Parasites

Two Kingdoms have organisms that are true parasites to domestic animals

Kingdom ____________

Kingdom ____________

Ectoparasites

Kingdom Animalia (mites, _______, mosquitoes, and _______)

Endoparasites

Kingdom Animalia (___________, flatworms, thorny-headed worms, and

_____________)

Kingdom _________ (protozoa)

* Protozoan parasites are __________________

Dichotomous Key:

Student


U.1.1 Student Handout 2: Endoparasite

Dichotomous Key Parasite Sleuth

1. Life Stage

a. Adult/worm like – go to 2

b. Immature (Egg or segment) – go to 13

2. Type

a. Multicellular animal – go to 3

b. Unicellular protozoan – Giardia

3. Body Shape

a. Adult is flattened – go to 4

b. Adult is rounded – go to 6

4. Segmentation

a. Adult is segmented – go to 5

b. Adult is not segmented – Liver Fluke

5. Intermediate Host

a. Rabbit – Taenia Tapeworm

b. Flea – Dipylidium – Flea Tapeworm

6. Preferred Tissue

a. Adult lives in tissue outside of the gastrointestinal tract – go to 7

b. Adult lives in the gastrointestinal tract – go to 9

7. System Specialization

a. Parasite most commonly affects the circulatory system of dogs – go to 8

b. Adult is most often found in terminal bronchioles of the respiratory system

- Lungworm

8. Size and Scale

a. Parasite is found in the right ventricle and arteries – Adult Heartworm

b. Parasite is found throughout the blood in the circulatory system –

Heartworm Microfilaria

9. Digestive Organ Specialization

a. Small intestine – go to 10

b. Other organ – go to 11

Student


10. Mouth Opening

a. Teeth attach the worm to the intestinal wall where it sucks blood –

Hookworm

b. Large lips and small teeth to feed on intestinal contents – Roundworm

11. Egg Laying

a. Adult females lay eggs on exterior of the body – Pinworms

b. Eggs are laid internally and excreted in feces – go to 12

12. Shape and Size

a. Uniformly cylindrical worm – Horse Strongyles

b. Worm with anterior small and filament like with thick posterior –

- Whipworm

13. Egg or Segment

a. Egg – go to 15

b. Segment – go to 14

14. Pores

a. Single lateral pore present – Taenia Tapeworm Segment

b. Double lateral pores present – Flea Tapeworm Segment

15. Group of Eggs

a. Eggs in packets – Flea Tapeworm Egg

b. Eggs single - go to 16

16. Shell

a. Thick walled - go to 17

b. Thin walled - go to 18

17. Round or Oval Thick-walled Egg

a. Small, smooth, striated – Taenia Tapeworm Egg

b. Large and rough – Roundworm Egg

18. Thin-walled Egg

a. Morulated (larvated) embryo – Hookworm Egg

b. Single or double-celled embryo - go to 19

19. Single or Double-celled Embryo and Oval, Thin-walled Shell

a. Bilateral polar plugs, football shaped – Trichuris

b. Small (round to oval) - Coccidia

Student


U.1.1 Student Handout 3: Ectoparasite

Dichotomous Key Parasite Sleuth

A. Adult Body Type

a. Segmented with six legs… go to B

b. Unsegmented with eight legs… go to K

B. Insects

a. Adult… go to C

b. Immature (wormlike)… go to G

C. Adult insects

a. Wingless… go to D

b. With wings… go to F

D. Fleas and Lice

a. Body compressed (flattened) dorsoventrally… go to E

b. Body compressed laterally… Flea

E. Lice

a. Head narrower than body… Sucking Louse

b. Head wider than body… Biting Louse

F. Color and Size

a. Iridescent blue or green body… Blow Fly

b. Very large and beelike, hairy body… Horse Bot

c. Very small with long legs and proboscis… Mosquito

G. Larval Insects – Hair

a. No hair… Blow Fly Maggot

b. Hair… go to H

H. Larval Size

a. Larva .25 cm. to .5 cm… go to I

b. Larva 2.5 cm. or more… go to J

I. Larva Environment

a. Larva found in water… Mosquito Larva

b. Larva found in dry environments where animals live… Flea Larva

Student


J. Larval Color

a. Black and spiny segments… Cat Warble

b. Cream to dark brown and spiny… Cattle Grub

K. Arachnids

a. < 1 mm… go to L

b. > 1 mm… Ticks

L. Mites

a. Round or oval… Go to M

b. Cigar-shaped with short legs… Demodectic Mite

M. Mites

a. Oval with short legs and long pedicels… Sarcoptic Mite

b. Oval with long legs and short pedicels… Ear Mite

Student


U.1.1 Student Handout 4: Parasite Sleuth Parasite Descriptions

Name:

Directions: Work with your partner to identify the parasite pictures using the

dichotomous keys given to you. After you have identified the parasite, list some

descriptive characteristics of the parasite in the second box.

Number: Parasite Name: Description:

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

Parasite ID


Name:

Number: Parasite Name: Description:

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

Parasite ID

U.1.1: Evaluation

U.1.1 Evaluation: Parasite Identification Parasite Sleuth

Name:

Identify the parasites below:

1.

2.

3.

Evaluation

U.1.1: Evaluation

Name:

4.

5.

6.

7.

Evaluation

U.1.1: Evaluation

Name:

8.

9.

10.

Evaluation

U.1.1: Post-test

U.1.1 Post-test: Parasite Sleuth Name:

1. Giardia, a parasite that is a protozoan, is classified in which Kingdom?

A. Kingdom Plantae

B. Kingdom Animalia

C. Kingdom Protista

D. Kingdom Fungi

2. A type of parasite (e.g., tapeworm, roundworm) that causes infection inside an

animal is considered a/an ___?___.

A. Insect

B. Endoparasite

C. Ectoparasite

D. Vector

3. Which of the choices is an example of an ectoparasite?

A. Mites

B. Hookworm

C. Pinworm

D. Tapeworm

4. The level of classification that is the most specific in our system of taxonomy

is ___?___.

A. Kingdom

B. Phylum

C. Class

D. Species

5. A parasite that draws blood, irritates the skin, and causes restlessness is most

likely a/an

A. Ectoparasite

B. Endoparasite

C. Helminth

D. Vector

Post-test

U.1.1: Additional Instructor Resources

U.1.1 Additional Instructor Resources: Key

Parasite Sleuth Student Assessment Key:

1. Cat Warble

2. Mosquito Larvae

3. Taenia Tapeworm Egg

4. Whipworm Adult

5. Hookworm Egg

6. Giardia

7. Heartworm Adult

8. Fleas Adult

9. Blowfly

10. Hookworm Adult

Instructor

Unit U: Parasitology

Documents

Transcript of Unit U: Parasitology