The first invertebrates to develop a true nervous system are
sponges
coelenterates
annelids
arthropods
Correct Answer :
B. coelenterates
Related Questions
If nematocysts are absent in Hydra, which is affected
Locomotion
Predation
Both (a) and (b)
Reproduction
Hydra is
marine, radial, symmetrical and diploblastic
fresh water, biradial, symmetrical and triploblastic
fresh water, radial, symmetrical and diploblastic
marine, radial, symmetrical and triploblastic
A chitinous material is present in the
coenosarc of Obelia
perisarc of Obelia
body wall of Sea anemone
umbrella of Aurelia
The number of tentacles in Hydra is
24
610
1040
4050
Nematocysts of Hydra are important for
cataching prey
paralysing prey
testing the food
testing the water
Enteron is divided by mesentries in
Aurelia
Sea anemone
Obelia
Hydra
The first invertebrates to develop a true nervous system are
sponges
coelenterates
annelids
arthropods
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
Hydra is put under phylum coelentrata because it has
tentacles
cnidoblasts
hypostome
interstitial cells
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
A coelentrate, commonly known as fresh water polyp is
Hydra
Obelia
Physalia
Acerelia
Musculo-glandular cells are found in hydra
on the tentacles
on the hypostome
on the basal disc
in the gastrodermis
In Hydra, the physiological division of labour is exhibited by
cellular layers
tissues
cell differentiation
organs
The nematocysts develop from
musculo-epithelial cells
interstitial cells
digestive cells
nerve cell
Which one is found in Hydra
Metabolism
Metamerism
Melting
Metamorphosis
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
Polymorphic coelentrates are the members of the class
hydrozoa
scyphozoa
actinozoa
all of these
The small green alga that lives inside Hydra is called
Zoochlorella
Chlamydomonas
Euglena
None of these
Nutritionally Hydra is
saprozoic
herbivorous
insectivorous
carnivorous
Among coelenterates medusoid individuals are absent in members of the class
hydrozoa
scyphozoa
anthozoa
all the three
Coelenteron of Hydra serves the double purpose of
digestion and circulation
digestion and storage
excretion and locomotion
circulation and storage
Green Hydra is
Hydra vulgaris
Chlorohydra viridisma
Hydra oligaetis
None of these
Rhopalia are the sense organs in medusa belonging to the class
hydrozoa
scyphozoa
actinozoa
all of these
Coelenteron in Hydra serves the purpose of
digestion and circulation
digestion and storage
excretion and digestion
circulation and storage
In Hydra, the absence of circulatory system is fulfilled by
ectoderm
endoderm
mesoglea
coelenteron
Hydra respires through
mesoglea
general surface
pellicle
gastrodermis
Ctenophores generally exhibit
bilateral symmetry
radial symmetry
asymmetry
spherical symmetry
"Portuguese Man of War" is the common name for
Aurelia
Metridium
Physalia
Tubipora
Which of the following animals has a nervous system but no brain ?
Earthworm
Hydra
Amoeba
Cockroach
The body wall of Hydra consists of
ecotderm and endoderm
ectoderm and mesoderm
ectoderm, mesoderm and endoderm
epidermis, mesoglea and endoderm