Which of the following organisms belongs to Coelenterata (Cnidaria)?
- A.Planaria and liverfluke
- B.Sea urchin and sea cucumber
- C.Hydra and sea anemone
- D.Euplectella and sycon
Correct answer
Explanation
The correct answer is C, Hydra and sea anemone. Both are cnidarians, simple aquatic animals with stinging cells.
Members of phylum Coelenterata (Cnidaria) have radial symmetry, two body layers, a single opening that works as both mouth and anus, and stinging cells called cnidoblasts on their tentacles, used to catch prey and for defence. Hydra lives in fresh water, while sea anemones, jellyfish, corals and Physalia (Portuguese man-of-war) live in the sea. Many show two body forms, the fixed polyp and the free-swimming medusa.
A is wrong: Planaria and the liver fluke are flatworms of phylum Platyhelminthes.
B is wrong: sea urchins and sea cucumbers are spiny-skinned marine animals of phylum Echinodermata.
D is wrong: Euplectella (Venus's flower basket) and Sycon are sponges of phylum Porifera.
Exam tip: Porifera = Sycon, Spongilla, Euplectella; Cnidaria = Hydra, Aurelia, sea anemone, corals; Platyhelminthes = Planaria, Fasciola, Taenia; Echinodermata = starfish, sea urchin, sea cucumber.
Practice Questions
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- A.Hg
- B.Si
- C.Ti
- D.Sn
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Quartz is silicon dioxide (SiO 2 ), so it contains silicon and oxygen. Quartz is one of the most common minerals in the Earth's crust and the main part of sand.
Read the full explanation →Epidermal cells of plant roots increase their absorption surface by having
- A.Scales
- B.Root hairs
- C.Endodermis
- D.Stomata
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Read the full explanation →Bending of shoot of a plant towards light can be referred to as
- A.photonasty
- B.positive phototropism
- C.negative phototropism
- D.photoperiodism
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Read the full explanation →Recently, there was a growing awareness in our country about the importance of Himalayan nettle (Girardinia diversifolia) because it is found to be a sustainable source of
- A.anti-malarial drug
- B.biodiesel
- C.pulp for paper industry
- D.textile fibre
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Read the full explanation →Which of the following statements are correct regarding the general difference between plant and animal cells ? 1. Plant cells have cellulose cell walls whilst animal cells do not. 2. Plant cells do not have plasma membrane unlike animal cells which do. 3. Mature plant cell has one large vacuole whilst animal cell has many small vacuoles. Select the correct answer using the code given below:
- A.1 and 2 only
- B.2 and 3 only
- C.1 and 3 only
- D.1,2 and 3
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Read the full explanation →