Remark: • Operculum (gill cover) is a feature of Osteichthyes (bony fishes). • Parapodia are lateral appendages in Annelida (e.g., Nereis). • The mantle cavity, containing gills, is found in Mollusca. • Pinnae (external ears) are present in Mammalia.
Q325.
List-I (Body Form)
List-II (Example)
(a) Dorso-ventrally flattened body
i) Ascaris
(b) Circular body in cross-section
ii) Taenia
(c) Umbrella-shaped body (Medusa)
iii) Adamsia
(d) Cylindrical body (Polyp)
iv) Aurelia
[Animal-Kingdom] [class-xi]
A) a-iv, b-iii, c-i, d-ii
B) a-iii, b-ii, c-iv, d-i
C) a-ii, b-i, c-iii, d-iv
D) a-ii, b-i, c-iv, d-iii
Correct Option: D [ D ]
Remark: • Taenia (tapeworm) is dorso-ventrally flattened. • Ascaris (roundworm) is circular in cross-section. • Aurelia (jellyfish) exhibits the umbrella-shaped medusa form. • Adamsia (sea anemone) has a cylindrical polyp form.
Remark: • Dioecious: sexes are separate. • Monoecious (hermaphrodite): sexes not separate. • Indirect development: involves a larval stage distinct from adult. • Direct development: young resemble the adult.
Remark: • Pseudocoelom: found in Aschelminthes. • True coelom first appears in Annelida. • Platyhelminthes are acoelomate. • Post-anal tail: a fundamental characteristic of Chordata.
