(1) Pseudocoelomates

Question 1

Characteristic Pseudocoelomate/tube-within-a-tube

Answer 1

1. Gut surrounded by a second (body) cavity (coelom)
2. but not lined with mesoderm completely
3. Tripoblastic
4. Complete (one-way) digestive system
5. Dioecious (two individuals/ two sexes)

Question 2

Advantages of a coelom (Pseudocoelomates)

Answer 2

1. more space for internal complecity
2. greater surface area to support viscera
3. flexibility
4. hydrostatic support (water skeleton)

Question 3

Phylum Nematoda

Answer 3

Roundworms

Question 4

Characteristics (Phylum Nematoda)

Answer 4

1. Freshwater, marine, soil, endoparasite (internal) = everywhere
2. Carnivores, plant juices, saprophytes, or parasites

Question 5

Unique Support System (Phylum Nematoda)

Answer 5

1. Nonliving, external, elastic, through exterior = cuticle
2. only longitudinal muscles, not circular
3. fluid filled forms a hydrostatic skeleton

Question 6

Hydrostatic Skeleton (Phylum Nematoda)

Answer 6

1. Muscle contraction bends the cuticle on one side (shortening)
2. force is transmitted by the body fluid, stretching the cuticle on another side (lengthening)
3. Muscle on the first side relaxes; worm returns to the original position

*cuticle opposes the longitudinal muscles

Question 7

Life Cycle (Phylum Nematoda)

Answer 7

1. Egg shed with feces
2. Ingested-plants, soil, hands
3. Juveniles burrow from intestine to circulatory system
4. carried to lungs, mature
5. up bronchi/ trachea, swallowed to intestines

Question 8

Symptoms (Phylum Nematoda)

Answer 8

1. Usually none
2. Abdominal pain
3. Intestinal blockage

Question 9

Control/ Prevention (Phylum Nematoda)

Answer 9

clean and cook plants
wash hands

Question 10

Hookworms Life Cycle

Answer 10

1. eggs pass in feces, hatch, feed on soil bacteria, penetrate skin to blood, then lungs, mature, on to intestine via throat
2. rasp inside of large intestine, suck blood

Question 11

Hookworms Symptoms

Answer 11

anemia, fatigue, can cause physical and mental retardation in children

Question 12

Hookworm Prevention

Answer 12

wear shoes

Question 13

Pinworms Life Cycle

Answer 13

1. Adult females migrate from small intestine to anus to lay eggs
2. resultant itch produces scratching and reinfection or infection via eggs on clothing

Question 14

Pinworm Symptom

Answer 14

itching

Question 15

Pinworm Control

Answer 15

Drugs

Question 16

Trichinellas Life Cycle

Answer 16

1. Ingestion of undercooked pork, bear meat
2. larvae released, mature, live in small intestine, produces new larvae
3. larvae eventually form cyst in muscle

Question 17

Trichinellas Symptoms

Answer 17

nausea, vomiting, sweating, diarrhea, more serious complications

Question 18

Trichinellas Prevention

Answer 18

cook meat

Question 19

Filarial Worms

Answer 19

1. Dog heart-worm (mosquito transmit)
2. Elephantiasis (swelling in lymph system)

Question 20

Helminth Worms

Answer 20

General term used to describe worm-like animals that are parasites

Example: tapeworms, flukes, roundworms,
-not segmented worms nor leeches