Transcript Honors Biology: Roundworms (continued) Feeding, Respiration

HONORS BIOLOGY: ROUNDWORMS
(CONTINUED)
FEEDING, RESPIRATION,
CIRCULATION, EXCRETION, RESPONSE,
MOVEMENT, REPRODUCTION & TYPES
Mr. Gibson Room 213
w/o May 9th
ROUNDWORMS: CONTINUED
Review of structure
(physiology)

They have a
“hydrostatic
skeleton” (water – not
moving) due to a fluid
filled gastrovascular
cavity that contains
NO complex
digestive organs, but
DOES have two
openings – mouth &
anus.
ROUNDWORMS: CONTINUED
Review of structure
(physiology)

The “hydrostatic
skeleton” is caused by
the fluid inside the
endoderm lined
gastrovascular cavity
pushing outward (like
a water balloon does
as is fills up). This
outward force (by the
fluid) is called tugor
pressure.
ROUNDWORMS: CONTINUED
Review of structure
(physiology)
•
In summary: The
“hydrostatic skeleton”
caused by the fluid
filled endoderm lined
gastrovascular cavity
pushing outward as
tugor pressure …
[…] classifies
roundworms as
pseudocoelomates.
(“pseudo” = “like”)
ROUNDWORMS: CONTINUED
Review of structure
(physiology)

The roundworm’s
outer body (ectoderm)
is “unsegmented”…
which means it is
smooth & without any
rings or segments.
ROUNDWORMS: CONTINUED
•
Reproduction
•
•
•
The roundworms are
“male” and “female”
(NOT hermaphrodites).
They rely on sexual
reproduction.
More specifically,
internal sexual
reproduction (means
the male’s sperm
fertilized the female’s
egg INSIDE her body).
ROUNDWORMS: CONTINUED
•
Feeding
•
•
The roundworms’
mouth has “grasping
mouth pieces” which
means they can grip
and hold onto their
prey (host) as they
feed off of them.
This also makes them
parasitic
heterotrophic
carnivores.
ROUNDWORMS: CONTINUED
•
Respiration, circulation,
& excretion:
•
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Like flatworms…
roundworms use
diffusion through their
body walls [to] move
gases & materials
into/out of their cells.
They have no internal
transport system
(digestive system, blood
circulatory system, or
breathing system)
ROUNDWORMS: CONTINUED
•
Response:
•
•
Roundworms… like
flatworms have a simple
nervous system
consisting of the same:
a) ganglia (nerve ring)
b) ventral nerve chords
(that run the length of
the body)
c) transverse nerves
They also have chemical
& vibratory sensors for
locating prey &
predators.
ROUNDWORMS: CONTINUED

Movement:
http://animal.discovery.com/videos/monstersinside-me-the-baylisascaris-parasite.html
Roundworms have
muscles that run the
length of their bodies.
 The fluid in the
pseudocoelom
combined with the
muscles serve to
expand & contract
thus “move” the
animal by “pushing”
or “pulling”
themselves along.

ROUNDWORMS: CONTINUED

Four major types of
roundworms:
•
1.
Roundworms are
classified as being:
Trichinosis-causing;
2.
Filarial;
3.
Ascarid;
4.
Hook.