A chitinous material is present in the
coenosarc of Obelia
perisarc of Obelia
body wall of Sea anemone
umbrella of Aurelia
Correct Answer :
B. perisarc of Obelia
Related Questions
Musculo-glandular cells are found in hydra
on the tentacles
on the hypostome
on the basal disc
in the gastrodermis
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
Brain coral is
Fungia
Hydra
Meandria
Tubipora
The tentacles of Hydra are
pinnate
hollow
solid
frilled
Strobilization is the characteristic feature of
Aurelia
Hydra
Metridium
Physalia
The nematocysts develop from
musculo-epithelial cells
interstitial cells
digestive cells
nerve cell
In Hydra, buds always arise at
the hypostome
the junction of hypostome and stomach
in junction of stomach and stalk
the stomach
In jelly fishes, the adult is always
polypoid
medusoid
polymorphic
hydroid
Cindom is a
battery of nematocysts
group of nematocysts
armed thread
none of these
Hydra is
marine, radial, symmetrical and diploblastic
fresh water, biradial, symmetrical and triploblastic
fresh water, radial, symmetrical and diploblastic
marine, radial, symmetrical and triploblastic
Six septa or six mesenteries are characteristic of
Aurelia
Sea anemone
Obelia
Hydra
Digestion in Hydra is
intracellular
extracellular
first extracellular, then intracellular
first intracellular, then extracellular
The first invertebrates to develop a true nervous system are
sponges
coelenterates
annelids
arthropods
In Hydra, the gastrodermis is composed of
musculo-epithelial cells
musculo-nutritive cells
sensory cells
cniboblasts
Rhopalia are the sense organs in medusa belonging to the class
hydrozoa
scyphozoa
actinozoa
all of these
Polymorphism is best defined as the occurrence of
several types of organ-systems in an individual
different kinds of larval forms in the life history of an animal
different functions performed by a single kind of organism
several different types of individuals in a species
What is common between Hydra and Obelia ?
Both show polymorphism
Both possess a larval stage in their life history called planula
Both are found in fresh water
Both havb a jelly like mesoglea with no cells
Polymorphic coelentrates are the members of the class
hydrozoa
scyphozoa
actinozoa
all of these
Hydra reproduces by gemmation (budding) when
Plenty of food is present
Pond dries up
Water becomes muddy
Hydra is alone
The mouth opens into a large single cavity in Hydra
coelom
enterocoel
pseudocoel
coelenteron
Tentaculocysts in Obelia are meant for
locomotion
balancing
swimming
reproduction
What structures in Hydra functionally correspond to the pseudopodia of Aamoeba ?
Endodermal cells
Mouth
Nematocysts
Tentacles
Division of labour on morphological basis is well exemplified by
Hydra
Obelia
Monkey
Elephant
Tentacles of Hydra help in
locomotion
food capturing
locomotion and food capturing
respiration
Which of the following tissue is absent in Hydra ?
Connective tissue
Epithelial tissue
Muscular tissue
Nervous tissue
Hydra is negatively chemotropic because it
prefers weak light
moves away from strong light
avoids chlorinated water
moves to water of low temperature
Nematocysts of Hydra are important for
cataching prey
paralysing prey
testing the food
testing the water
In Hydra, the nematocysts are abundant on
upper part
middle part
tentacles
lower part
The testes of hydra are located
below the ovaries
below the tentacles
further down the tentacles to occupy central position of the body
anywhere on the body between tentacles and adhesive disc
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