Practice question

Poriferan free-swimming larvae include amphiblastula hollow blastula with anterior hemisphere flagellated smaller micromeres and posterior hemisphere larger unflagellated macromeres characteristic of calcareous syconoid sponges, after inversion settles and flagellated cells become choanocytes. Parenchymella also called parenchymula or stereogastrula typical of demosponges solid structure with outer flagellated columnar epithelium surrounding inner mass of amoeboid cells. Both lecithotrophic planktonic dispersal forms. Planula belongs to cnidarians, trochophore to lophotrochozoans, veliger molluscan, bipinnaria echinoderm, nauplius and zoea crustacean decapod larvae not sponge. This concept holds high importance for NEET, CBSE board, CUET and competitive examinations focusing on comparative morphology