Q.Choose the correct statements.

Option (a) is the incorrectly matched pair — Veliger is the larva of Mollusca, not Ctenophora (whose larva is the cydippid larva); the other three pairs are all correct.

Many invertebrate phyla are identified in exams by their characteristic larval stage:

• Porifera → Parenchymula (and also amphiblastula in some sponges) — a ciliated larva.
• Cnidaria → Planula — a ciliated, free-swimming larva.
• Annelida (and Mollusca) → Trochophore — a top-shaped ciliated larva; in Annelida it is the trochophore larva, correctly paired here.
• Ctenophora → Cydippid larva — NOT the veliger. The veliger is specifically the larva of Mollusca (following the trochophore stage), where it develops a shell, foot, and velum. …

Statements (i) and (iii) are correct — a single left ovary is a genuine flight adaptation in female pigeons, and frogs do respire through their skin during aestivation/hibernation; statements (ii) and (iv) are factually incorrect.

Evaluating each statement:

1. TRUE — In female birds like the pigeon, only the left ovary and oviduct are functional; the right ovary regresses during development. This reduces body weight, an adaptation that supports efficient flight.
2. FALSE — The major flight muscles of the pigeon are the pectoralis major (depresses the wing, the main downstroke muscle) and the pectoralis minor/supracoracoideus (elevates the wing via a pulley-like tendon). Coracobrachialis is a minor muscle, not the major flight muscle. …