Communication between the enteron and exterior in coelentrates is through
mouth only
mouth and anus
large number of pores in the body wall
both (b) and (c)
Correct Answer :
A. mouth only
Related Questions
In Hydra, buds always arise at
the hypostome
the junction of hypostome and stomach
in junction of stomach and stalk
the stomach
The scientific name of organ pipe coral is
Tubipora
Astrangia
Meandra
Aeropora
Hydra is negatively chemotropic because it
prefers weak light
moves away from strong light
avoids chlorinated water
moves to water of low temperature
A hydranth is
Blastostyle of Obelia
Gonad of Hydra
Medusa of Obelia
Polyp of Obelia
Among coelenterates medusoid individuals are absent in members of the class
hydrozoa
scyphozoa
anthozoa
all the three
Division of labour on morphological basis is well exemplified by
Hydra
Obelia
Monkey
Elephant
"Portuguese Man of War" is the common name for
Aurelia
Metridium
Physalia
Tubipora
Enteron is divided by mesentries in
Aurelia
Sea anemone
Obelia
Hydra
Strobilization is the characteristic feature of
Aurelia
Hydra
Metridium
Physalia
In Hydra, the nematocysts are abundant on
upper part
middle part
tentacles
lower part
The mesoglea present in Hydra in between epidermis and gastrodermis is
non-cellular and jelly like material
cellular jelly like material containing sensory cells
cellular jelly like material containing nerve cells
both (a) and (c)
Polymorphism is found in
Hydra
Aleyonium
Aurelia
Physalia
A piece of Hydra will regenerate into a full Hydra if it contains a part of
epidermis alone
gastrodermis alone
both (a) and (b)
(a), (b) and tentacles
Coelenteron in Hydra serves the purpose of
digestion and circulation
digestion and storage
excretion and digestion
circulation and storage
In Hydra, the gastrodermis is composed of
musculo-epithelial cells
musculo-nutritive cells
sensory cells
cniboblasts
If nematocysts are absent in Hydra, which is affected
Locomotion
Predation
Both (a) and (b)
Reproduction
The mesoglea in Hydra is traversed by
sensory cells
nerve cells
interstitial cells
all of these
Hydra prevents self fertilization by being
protogynous
hermaphrodite
monoecious
protandrous
Ctenophores differ form cnidorians in one important aspect, that is
absence of musculoepithelial cells in the body wall
absence of nematocysts
absence of sensory cells
absence of sexual reproduction
If a Hydra is cut into two pieces, it is noted that
both parts die
both parts make up the loss and form two new individuals
both parts live independently as they are
none of these
Rhopalia are the sense organs in medusa belonging to the class
hydrozoa
scyphozoa
actinozoa
all of these
The mouth opens into a large single cavity in Hydra
coelom
enterocoel
pseudocoel
coelenteron
In Hydra, the physiological division of labour is exhibited by
cellular layers
tissues
cell differentiation
organs
Which of the following animals has a nervous system but no brain ?
Earthworm
Hydra
Amoeba
Cockroach
In jelly fishes, the adult is always
polypoid
medusoid
polymorphic
hydroid
Tentacles of Hydra help in
locomotion
food capturing
locomotion and food capturing
respiration
Six septa or six mesenteries are characteristic of
Aurelia
Sea anemone
Obelia
Hydra
The tentacles of Hydra are
pinnate
hollow
solid
frilled
Hydra respires through
mesoglea
general surface
pellicle
gastrodermis
Musculo-glandular cells are found in hydra
on the tentacles
on the hypostome
on the basal disc
in the gastrodermis