Entities of phylum coelenterata are typically found secured to the rocks at the bottom of the sea. Coelenterates are multicellular entities that can be occurring in solitude or in colonies and are the most uncomplicated group of invertebrates. The mouth of such entities is engirdled by short and thin tentacles. Explore MCQs on coelenterates here.
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These aquatic entities have a body structure that is radially symmetric and are diploblastic and lacks coelom. Their body has a hypostome – a single opening, which is bordered by sensory tentacles supplied with colloblasts or nematocysts in order to trap planktonic prey. The tentacles are girdled by the gastrovascular cavity or the coelenteron which is a spacious cavity. Digestion in coelenterates is both through extracellular and intracellular means while simple diffusion is the means by which excretion and respiration is carried out.
1. Pick the most suitable terminology to designate life cycle of Obelia
(a) Metamorphosis
(b) Neoteny
(c) Metagenesis
(d) None of the above
Answer: (c)
2. This group is commonly known as ‘sea stick’
(a) Porifera
(b) Coelenterata
(c) Arthropoda
(d) Echinodermata
Answer: (b)
3. This does not belong to Phylum Coelenterata
(a) Sea cucumber
(b) Sea feather
(c) Sea pen
(d) Sea fan
Answer: (a)
4. A coelenterate that is commonly referred to as ‘fresh water polyp’ is
(a) Obelia
(b) Physalia
(c) Hydra
(d) Aurelia
Answer: (c)
5. This is a special character of coelenterata occurring only in them
(a) Flame cells
(b) Hermaphroditism
(c) Nematocysts
(d) Polymorphism
Answer: (c)
6. The characteristic larva in coelenterates is
(a) Oncosphere
(b) Rhabditiform
(c) Planula
(d) Cysticercus
Answer: (c)
7. Oxygen in coelenterates is supplied to different tissues by
(a) Plasma
(b) Diffuses through integuments
(c) Blood pigment
(d) Tracheal tubes
Answer: (b)
8. The class of coelenterata in which the medusa and polyp both are found in one animal is
(a) Anthozoa
(b) Hydrozoa
(c) Scyphozoa
(d) None of the above
Answer: (b)
9. This phylum shows the presence of nerve cells and absence of nerves
(a) Coelenterata
(b) Porifera
(c) Nemathelminthes
(d) Platyhelminthes
Answer: (a)
10. This is a characteristic feature of coelenterata
(a) Polyp
(b) Gastrovascular cavity
(c) All are marine
(d) Presence of tentacles around mouth
Answer: (b)
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