Hydra reproduces by gemmation (budding) when
Plenty of food is present
Pond dries up
Water becomes muddy
Hydra is alone
Correct Answer :
A. Plenty of food is present
Related Questions
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
The scientific name of organ pipe coral is
Tubipora
Astrangia
Meandra
Aeropora
The number of tentacles in Hydra is
24
610
1040
4050
In Hydra, the physiological division of labour is exhibited by
cellular layers
tissues
cell differentiation
organs
Among coelenterates medusoid individuals are absent in members of the class
hydrozoa
scyphozoa
anthozoa
all the three
The mesoglea in Hydra is traversed by
sensory cells
nerve cells
interstitial cells
all of these
Nematocysts of Hydra are important for
cataching prey
paralysing prey
testing the food
testing the water
Hydra reproduces by budding when
plenty of food is present
pond is going dry
Hydra is alone
water becomes muddy
Hydra has no special structure for
attachment
respiration
food capturing
offense
Polymorphic coelentrates are the members of the class
hydrozoa
scyphozoa
actinozoa
all of these
In Hydra, buds always arise at
the hypostome
the junction of hypostome and stomach
in junction of stomach and stalk
the stomach
A Hydra usually possess
single testis and many ovaries
single ovary and many testes
one testis and one ovary
many testes and many ovaries
Brain coral is
Fungia
Hydra
Meandria
Tubipora
A hydranth is
Blastostyle of Obelia
Gonad of Hydra
Medusa of Obelia
Polyp of Obelia
The body wall of Hydra consists of
ecotderm and endoderm
ectoderm and mesoderm
ectoderm, mesoderm and endoderm
epidermis, mesoglea and endoderm
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
Which of the following tissue is absent in Hydra ?
Connective tissue
Epithelial tissue
Muscular tissue
Nervous tissue
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
Strobilization is the characteristic feature of
Aurelia
Hydra
Metridium
Physalia
Green Hydra is
Hydra vulgaris
Chlorohydra viridisma
Hydra oligaetis
None of these
In jelly fishes, the adult is always
polypoid
medusoid
polymorphic
hydroid
Which one is found in Hydra
Metabolism
Metamerism
Melting
Metamorphosis
Coelenteron in Hydra serves the purpose of
digestion and circulation
digestion and storage
excretion and digestion
circulation and storage
If nematocysts are absent in Hydra, which is affected
Locomotion
Predation
Both (a) and (b)
Reproduction
Most favourite food of Hydra is
bacteria
water fleas
tadpoles
fishes
The poisonous fluid present in the nematocysts of Hydra is
toxin
venom
hypnotoxin
haematin
Cindom is a
battery of nematocysts
group of nematocysts
armed thread
none of these
A chitinous material is present in the
coenosarc of Obelia
perisarc of Obelia
body wall of Sea anemone
umbrella of Aurelia
The tentacles of Hydra are
pinnate
hollow
solid
frilled
In Hydra, the gastrodermis is composed of
musculo-epithelial cells
musculo-nutritive cells
sensory cells
cniboblasts