| Assertion (A): | Hemichordata was earlier considered as a sub-phylum under phylum Chordata but now it is placed as a separate phylum under non-chordata. |
| Reason (R): | Hemichordates have a rudimentary structure in the collar region called stomochord, a structure analogous to notochord. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
In which of the following animals, the body is cylindrical and is composed of an anterior proboscis, a collar and a long trunk?
| 1. | Hemichordates | 2. | Urochordates |
| 3. | Cephalochordates | 4. | Vertebrate chordates |
The number of correct statements regarding hemichordates from the given is:
| I: | A stomochord is present in the collar region |
| II: | Circulation is of open type |
| III: | Excretory organ is proboscis gland |
| IV: | Development is indirect |
| 1. | 1 | 2. | 2 |
| 3. | 3 | 4. | 4 |
| 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 |
| 1. | Urochordates | 2. | Cephalochordates |
| 3. | Hemichordates | 4. | Vertebrate chordates |