I: | The most unique characteristic is the presence of mammary glands. |
II: | Skin is unique in possessing hair. |
III: | Heart is unique in being four-chambered. |
IV: | Viviparity is a unique feature. |
I: | are exclusively marine and mostly asymmetrical animals. |
II: | have cellular level of organisation. |
III: | have a water transport or canal system. |
IV: | have extracellular digestion. |
A | B | C | D | |
1 | Nerve cord |
Notochord | Gill slits | Terminal anus |
2 | Notochord | Nerve cord | Gill slits | Post anal tail |
3 | Nerve cord |
Notochord | Gill slits | Post anal tail |
4 | Notochord | Nerve cord | Muscle myotome |
Terminal anus |
Assertion (A): | Aschelminthes are called round worms. |
Reason (R): | The body of the aschelminthes is circular in cross-section. |
1. | (A) is True but (R) is False. |
2. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
3. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
4. | (A) is False but (R) is True. |
A: | Unlike platyhelminthes, annelids have an incomplete digestive system. |
B: | Unlike arthropods, annelids have an open circulatory system. |
C: | Unlike aschelminthes, annelids have a pseudocoelom. |
D: | Unlike chordates, the body of annelids is not metamerically segmented. |
Column I | Column II | ||
A. | Petromyzon and Myxine | P. | Cyclostome |
B. | Amphioxus or Lancelet | Q. | Cephalochordate |
C. | Ascidia and Salpa | R. | Urochordate |
A | B | C | |
1. | P | Q | R |
2. | R | Q | P |
3. | P | R | Q |
4. | R | P | Q |
I: | Digestive system is complete with mouth on the lower (ventral) side and anus on the upper (dorsal) side. |
II: | An excretory system is absent. |