The structure shown in the given diagram is characteristically seen in the Phylum:

1. Porifera

2. Ctenophora

3. Cnidaria

4. Molluska

Metagenesis refers to

1. the presence of different morphic forms

2. alternation of generation between asexual and sexual phases of an organism

3. occurance of a drastic change in form during post embryonic development

4. the presence of a segmented body and parthenogenetic mode of reproduction

Stinging capsules (nematocysts) are found in

(1) wasp and honeybee

(2) scorpion and cobra

(3) sea pen and sea fan

(4) cactus and Venus flytrap

The digestive system in Meandrina is

(1) Digestion is extracellular only

(2) Digestion is intracellular only

(3) Digestion is both extracellular and intracellular

(4) Digestion absent as it is a parasite

Both polyp and medusa life forms are present in the life cycle of

(1) Obelia

(2) Physalia

(3) Aurelia

(4) Adamsia

The skeleton of corals is made up of

(1) Calcium silicate

(2) Calcium phosphate

(3) Hydroxyapatite

(4) Calcium carbonate

Which of the following group consists exclusively of cnidarians?

(1) Aplysia, Gorgonia, Spongilla, Hydra

(2) Hydra, pennatula, obelia, Echinus

(3) Hydra, obelia, adamsia, physalia

(4) Scypha, Hydra, adamsia, physalia

Nematocytes are present in

(1) Adamsia

(2) Hirudinaria

(3) Sycon

(4) Echinus

A sessile, cylindrical and radial symmetrical life form is found in

1. Hydra

2. Obelia

3. Adamsia

4. all of the above

Physalia is a coelenterate which is also known as

(1) sea pen

(2) sea fan

(3) Portuguese man of war

(4) sea anemone