Q. No.Identify the incorrect statement regarding Mollusca:
1.
It is the second largest animal Phylum after Phylum Arthropoda.
2.
It includes animals that are bilaterally symmetrical, triploblastic, and coelomate.
3.
Body is covered with a calcareous shell and is metamerically segmented with a distinct head, muscular foot, and visceral hump.
4.
Gills are present in the mantle cavity, a space between the mantle and the hump.
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| 1. | Pinctada | Pearl Oyster |
| 2. | Aplysia | Sea hare |
| 3. | Dentalium | Tusk shell |
| 4. | Loligo | Devil fish |
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| 1. | They have bilateral symmetry as adults and radial symmetry as larvae. |
| 2. | They are triploblastic and coelomates. |
| 3. | They possess a well-developed excretory system. |
| 4. | They have an incomplete digestive system. |
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| 1. | Sea Urchin | 2. | Sea lily |
| 3. | Brittle star | 4. | Brain coral |
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| Statement 1: | Hemichordates were earlier considered as a sub-phylum under Phylum Chordata but are now placed separately in a phylum under non-Chordata. |
| Statement 2: | Hemichordates have a rudimentary structure in the collar region called stomochord, a structure homologous to the notochord. |
| 1. | Both Statement 1 and Statement 2 are correct but Statement 2 does not explain Statement 1. |
| 2. | Statement 1 is correct and Statement 2 is incorrect. |
| 3. | Both Statement 1 and Statement 2 are incorrect. |
| 4. | Both Statement 1 and Statement 2 are correct and Statement 2 explains Statement 1. |
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| 1. | Circulatory system is a closed type |
| 2. | Proboscis gland is a digestive gland that secretes a large number of hydrolytic enzymes |
| 3. | Respiration takes place through the gills |
| 4. | Sexes are not separate, fertilization is internal and development is direct |
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| (a) | A notochord |
| (b) | Ventral, solid, and double central nervous system |
| (c) | Pharynx perforated by gill slits |
| (d) | Ventral heart |
| (e) | Terminal anus and a lack of post-anal tail |
| 1. | (a), (c), and (d) only | 2. | (a), (b) and (e) only |
| 3. | (a) and (c) only | 4. | (b), (c) and (d) only |
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| Statement I: | In Urochordata, notochord is present only in larval tail. |
| Statement II: | In Cephalochordata, notochord extends from head to tail region and is persistent throughout their life. |
| Statement III: | Both Urochordates and Cephalochordates are exclusively marine. |
1. Only Statement I and Statement II
2. Only Statement I and Statement III
3. Only Statement II and Statement III
4. Statement I, Statement II, and Statement III
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| Statement I: | All vertebrates are chordates but all chordates are not vertebrates. |
| Statement II: | Besides the basic chordate features, all vertebrates have at least a three-chambered heart and paired appendages. |
| 1. | Both Statement I and Statement II are correct but Statement II does not explain Statement I. |
| 2. | Statement I is correct and Statement II is incorrect. |
| 3. | Both Statement I and Statement II are incorrect. |
| 4. | Both Statement I and Statement II are correct and Statement II explains Statement I. |
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| A | B | C | D | |
| 1. | Phylum | Cephalochordata | Urochordata | Protochordata |
| 2. | Division | Agnatha | Super-Class | Pisces |
| 3. | Phylum | Protochordata | Infra-class | Jawless fishes |
| 4. | Division | Agnatha | Sub-division | Pisces |
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