1. Sponges | 2. Hydra |
3. Planaria | 4. Earthworm |
I: | This is seen in sponges, cnidarians, ctenophores and larval echinoderms. |
II: | This type of body symmetry is generally seen in animals which move actively in their environment. |
1. | Only I | 2. | Only II |
3. | Both I and II | 4. | Neither I nor II |
1. | Body will be bilaterally symmetrical |
2. | Muscle will be well developed |
3. | A true coelom will be present |
4. | Both will have cells organized into tissues and heterotrophic nutrition |
I: | This type of life cycle is called as metagenesis and it is a sort of alternation of generation. |
II: | Polyps in the life cycle of cnidarians are haploid and medusae are diploid. |
I: | Most sponges work rather like chimneys: they take in water at the bottom and eject it from the osculum ("little mouth") at the top. |
II: | The inner surface is covered with choanocytes where the wave-like motion of the whip-like flagella drives water through the sponge's body. |
1. A sponge | 2. A Cnidarian |
3. A Ctenophore | 4. A flatworm |
A: | I is found in all the molluscs. |
B: | II is a cavity used for egestion, excretion and respiration. |
A | B | C | D | E | F | |
1. | Blood vessel | Nerve cord | Trachea | Spiracles | Crop | Hearts |
2. | Blood vessel | Nerve cord | Trachea | Spiracles | Oesophagus | Hearts |
3. | Nerve cord | Blood vessel | Trachea | Spiracles | Crop | Ostia |
4. | Nerve cord | Blood vessel | Stomo- chord |
Ostia | Oesophagus | Spiracles |