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
Correct Answer :
D. Both havb a jelly like mesoglea with no cells
Related Questions
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
Which of the following animals has a nervous system but no brain ?
Earthworm
Hydra
Amoeba
Cockroach
In Hydra, the nematocysts are abundant on
upper part
middle part
tentacles
lower part
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
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
Coral reef formation is mainly related to
sponges
anthozoans
molluscs
hydrozoans
The mesoglea in Hydra is traversed by
sensory cells
nerve cells
interstitial cells
all of these
The body of Hydra is
asymmetrical
bilaterally symmetrical
radially symmetrical
irregular
Polymorphic coelentrates are the members of the class
hydrozoa
scyphozoa
actinozoa
all of these
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
Among coelenterates medusoid individuals are absent in members of the class
hydrozoa
scyphozoa
anthozoa
all the three
Digestion in Hydra is
intracellular
extracellular
first extracellular, then intracellular
first intracellular, then extracellular
The body wall of Hydra consists of
ecotderm and endoderm
ectoderm and mesoderm
ectoderm, mesoderm and endoderm
epidermis, mesoglea and endoderm
Nematocytes are the specialised cells found in the members of the phylum
porifera
coelentrata
annelida
platyhelminthes
Hydra reproduces by gemmation (budding) when
Plenty of food is present
Pond dries up
Water becomes muddy
Hydra is alone
Ephyra is the larval form of
Sea anemone
Aurelia
Obelia
Hydra
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
The flagella of food-absorbing cells in hydra aid in
stirring up the digestive fluid in the digestive cavity
engulfing food particles
engulfing semi-digested particles inside food- absorbing cells
none of these
"Portuguese Man of War" is the common name for
Aurelia
Metridium
Physalia
Tubipora
The tentacles of Hydra are
pinnate
hollow
solid
frilled
Hydra is negatively chemotropic because it
prefers weak light
moves away from strong light
avoids chlorinated water
moves to water of low temperature
The nematocysts develop from
musculo-epithelial cells
interstitial cells
digestive cells
nerve cell
If nematocysts are absent in Hydra, which is affected
Locomotion
Predation
Both (a) and (b)
Reproduction
Tentaculocysts in Obelia are meant for
locomotion
balancing
swimming
reproduction
Hydra is put under phylum coelentrata because it has
tentacles
cnidoblasts
hypostome
interstitial cells
In jelly fishes, the adult is always
polypoid
medusoid
polymorphic
hydroid
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
Tentacles of Hydra help in
locomotion
food capturing
locomotion and food capturing
respiration
What structures in Hydra functionally correspond to the pseudopodia of Aamoeba ?
Endodermal cells
Mouth
Nematocysts
Tentacles
A hydranth is
Blastostyle of Obelia
Gonad of Hydra
Medusa of Obelia
Polyp of Obelia