Tentaculocysts in Obelia are meant for
locomotion
balancing
swimming
reproduction
Correct Answer :
B. balancing
Related Questions
Ephyra is the larval form of
Sea anemone
Aurelia
Obelia
Hydra
Among coelenterates medusoid individuals are absent in members of the class
hydrozoa
scyphozoa
anthozoa
all the three
If nematocysts are absent in Hydra, which is affected
Locomotion
Predation
Both (a) and (b)
Reproduction
What structures in Hydra functionally correspond to the pseudopodia of Aamoeba ?
Endodermal cells
Mouth
Nematocysts
Tentacles
Tentaculocysts in Obelia are meant for
locomotion
balancing
swimming
reproduction
Hydra responds to a strong mechanical stimulus such as agitating the surface of water by
somersaulting
contracting a part or whole of its body
walking away
looping
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
In Hydra, the gastrodermis is composed of
musculo-epithelial cells
musculo-nutritive cells
sensory cells
cniboblasts
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)
Nematocysts of Hydra are important for
cataching prey
paralysing prey
testing the food
testing the water
The body of Hydra is
asymmetrical
bilaterally symmetrical
radially symmetrical
irregular
In jelly fishes, the adult is always
polypoid
medusoid
polymorphic
hydroid
Rhopalia are the sense organs in medusa belonging to the class
hydrozoa
scyphozoa
actinozoa
all of these
Hydra is negatively chemotropic because it
prefers weak light
moves away from strong light
avoids chlorinated water
moves to water of low temperature
Polymorphism is found in
Hydra
Aleyonium
Aurelia
Physalia
The tentacles of Hydra are
pinnate
hollow
solid
frilled
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
Most favourite food of Hydra is
bacteria
water fleas
tadpoles
fishes
The nematocysts which are mainly used for defense and offense and which tightly coil around the prey are
steptoline or atrichous
streptoline or holotrichous
volvent or desmonemes
penetrant or stenoteles
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
Musculo-glandular cells are found in hydra
on the tentacles
on the hypostome
on the basal disc
in the gastrodermis
Hydra is
marine, radial, symmetrical and diploblastic
fresh water, biradial, symmetrical and triploblastic
fresh water, radial, symmetrical and diploblastic
marine, radial, symmetrical and triploblastic
Hydra reproduces by budding when
plenty of food is present
pond is going dry
Hydra is alone
water becomes muddy
The body wall of Hydra consists of
ecotderm and endoderm
ectoderm and mesoderm
ectoderm, mesoderm and endoderm
epidermis, mesoglea and endoderm
Enteron is divided by mesentries in
Aurelia
Sea anemone
Obelia
Hydra
A Hydra usually possess
single testis and many ovaries
single ovary and many testes
one testis and one ovary
many testes and many ovaries
Hydra prevents self fertilization by being
protogynous
hermaphrodite
monoecious
protandrous
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
Digestion in Hydra is
intracellular
extracellular
first extracellular, then intracellular
first intracellular, then extracellular
Strobilization is the characteristic feature of
Aurelia
Hydra
Metridium
Physalia