See __
Experiment:
Name:
_
Ascaris An Example of Nematoda
(B. Science 10-1-27)
Purpose:
To observe some specializations of the
Ascaris, a more complex worm belonging to the
'phylum Nematoda (Roundworms).
microscope
:Materials: Ascaris
prepared slides of Ascaris (Ine 101 - 102)
i Trichinella
spiralis section in muscle
Methods:
1. There is just one class of Nematoda. Some
examples are the hookworm, trichina worm,
....
.
.
._
-pinworm, shipworm, and Ascaris.
The Ascaris is a large roundworm that may live in the intestine of pigs, horses, and
sometimes people.
2. Observe the Ascaris . What is the differences in sizes of the the male and female
Ascaris?
3. Label the following parts of the female adult Ascaris (include the cross -section):
anus, uterus, ovary, oviduct, vagina, female pore, excretory duct, intestine, esophagus,
excretory pore, lips, mouth. On cross-section include nerve cord, cuticle.
4. Examine a prepared whole - mount slide of a trichina worm (Trichinella) larva
encysted in muscle tissue under low power of microscope. Sketch and then label
trichina worm larva, cyst, and muscle tissue.
Results:
3.
2. male is:
This is a longitudinal
section of the internal
anatomy of a femaJe
Ascaris.
4. Trichinella
See: __
Name:
_
Conclusions:
1. What form of the Ascaris worm gets into the person "the host" by contaminated
food?
2. Once they get into the stomach they enter into the small intestines and what
happens to the eggs there?
3. After the larvae form how do they get from the intestine to the blood stream?
4. Once they are in the blood stream where do they go first?
5. Once they reach the lungs how do they get back into the digestive tube?
6. Now that they are in the digestive tube again, and they mature for 2 1/2 months
what form of the worm are they now?
7. The male adult fertilizes the egg of the female, how do these eggs reach water
supplies to contaminate them?
8. How many eggs could be laid in one day?
9. What is the best way to stop the infection of humans by Ascaris ?
Discussion:
1. The Nematoda is the first of the simple animals that has a 'tube within a tube'. This
is a digestive track within the body tube. What is the name of the two openings of this
tube within a tube?
a.
b.
2. Are Ascaris hermaphroditic?
3. Briefly describe how humans can get infected with:
hookworm:
I Trichinella:
I
I
I
I
I
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4. Deut. 14: 3 - 8. Give a scientific reason why God commanded us to not eat pig
(pork) ?