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 |
1. | 3 | 2. | 4 |
3. | 5 | 4. | 6 |
I: | They are marine but migrate for spawning to fresh water. |
II: | After spawning, within a few days, they die. |
III: | Their larvae, after metamorphosis, return to the ocean. |
1. | Petromyzon, Myxine |
2. | Ascidia, Salpa |
3. | Pristis, Doliolum |
4. | Branchiostoma, Balanoglossus |