Aschelminthes Flashcards
name
`nematodes - the round worms
nematode means
pointed ends
general information
bilateral symmetry
triploblastic
pseudocoelom`
unsegmented
body cavity is
pseudocoelom /false coelom
body cavity is
pseudocoelom /false coelom
body cavity is derived from
blastocoel - the fluid filled cavity of blastula
does mesoderm give rise to body cavity
no it doesnt, it give rise to body cavity in coelomates
fluid is present or not
it is present
where
in between body wall and alimentary canal
Digestive system
parasitic round worms- simplifeid digestive system
two openings
which have simplified digestive system
parasitic platyhelminthes and parasitic aschelmenthis
type of digestive system
- tube within a tube-like structure
- anus and a mouth
- anterior mouth and posterior anus
type of digestive system
- tube within a tube-like structure
- anus and a mouth
- anterior mouth and posterior anus
4.
structure of organism
tapering at both ends
type of digestive system
- tube within a tube-like structure
- anus and a mouth
- anterior mouth and posterior anus
4.
do they contain nephridie, metanephridia , protonephridia or none
protonephridia
type of digestive system
- tube within a tube-like structure
- anus and a mouth
- anterior mouth and posterior anus
4.
describe excretory system
two longitudinal canals that join at the anterior end to form a single canal tha opens into exterior through an extrernal opening present on the ventral side of the organism.
they have protonephridia
respiratory system
lack- occurs through body surface
nervous system
- nerve ring
- papillae
- special sensory organs
what is nerve ring
nerve ring of nerve tissue and ganglia is present around the pharynx and give rise to dorsal, lateral, and ventral nerve cords that are connected with transverse cords
are there transverse cords
yes- nbf
are there specialized sense organs in the anterior region of the organism
no, they are present in platyhelmenthis though
specialized sensory organs in the anterior region are presen in which phyla
what are pappillae
they are sense organs present at the lips at the anterior end.
what are papillae in humans
present in tonge
reproduction
- diecious, or separate sexes
- ovaries and testes
female
ovary
males
testes
is there a larval stage
yes
is the larval trochophore larvae
no
where is trochophore larvae preset then
muscular system
- noncontinuous
- four bands of muscles
desrcibe the muscles
four bands of muscles
1. 2 dorsolateral
2. 2 ventrolateral
no circular muscles
are there circular muscles
no
does bending occurs
yes
how
dorsolateral bending only due to absence of circular muscles
are there circular muscles present
no
size range
- moslty are 5cm
- microscopic parasites
- to one meter long
skeleton
hydrostatic skeleton
how is this hydrostatic skeleton obtained
presenve of vacuolated protien rich fluid filled cells.
circulatory system
absent
locomotion
undulating waves of contraction and relaxation of muscless
locomotion
undulating waves of contraction and relaxation of muscless
