5.2.5. Nematoda

Question 1

Second largest animal phylum
Largest Nematode measured 9 meters long and 2.5 cm in diameter, found as parasite in a Sperm Whale’s placenta.
Most exhibit Separate Sexes (Dioecious) and all have a Complete Gut.

Answer 1

PHYLUM : NEMATODA

Question 2

___- fluid-filled body cavity; false cavity is completely enclosed but it is NOT completely enclosed by mesodermal tissue.

Answer 2

Pseudo- coelom

Question 3

___- are relatively large nematodes found in a wide variety of aquatic and terrestrial vertebrates, mostly in Tropical and Subtropical Regions

Answer 3

Ascaridida

Question 4

A human intestinal parasite (male=30 cm; fem=40cm)
They produce about 200,000 eggs per DAY !!!!!
May live for many years in the human intestine.
Most damage is done when they migrate around bodily tissues then return to the gut to reach maturity.
Anti-Helminthic Drugs can be used to wipe out the worm infection

Answer 4

Ascaris lumbricoides

Question 5

is very tiny but they reproduce to block lymphatic vessels as a result tissue swelling (Edema) occurs.
Transmitted by mosquitoes, biting flies and ticks.

Answer 5

Filarial Worm

Question 6

the most common intestinal parasite in the U.S./Canada; occur most often in school-age children, but are highly contagious, and can easily spread to the entire family.

Answer 6

Pinworms (Enterobius vermicularis)

Question 7

Pinworm infections are detected by finding the eggs or worms on the ____

Answer 7

perianal skin

Question 8

from mosquito bites
feeds on blood
can grow up to 12 inches in length

Answer 8

Heartworms

Question 9

, can be found in many species of carnivores and omnivores. The larvae mature into adults in the host’s small intestine in a few weeks, and the female worms give birth to larvae.

Answer 9

Trichinella spiralis,

Question 10

is probably best known as a parasite that humans contract from eating raw or undercooked pork.

Answer 10

Trichinosis

Question 11

REPRODUCTION

• The majority of nematodes are ___ ;
that is, the sexes are separate. Some species,
however, some are ___, having both
male and female reproductive organs.

Answer 11

dioecious; hermaphroditic

Question 12

In most nematodes, the third larval stage – after the second molt – is
the ___ stage.

Answer 12

infective

Question 13

In the vertebrate retina, the light-sensitive cells convert light into electrical impulses by means of proteins called ____ ion channels

Answer 13

cyclic nucleotide-gated (CNG)