BIO EXAM 1

Which statement best defines Bilateria within animal diversity?

• Group of deuterostomes that are exclusively coelomate animals

• Clade including most triploblastic animals with bilateral symmetry

• Clade of mainly diploblastic animals with radial symmetry

• Superphylum of molting animals with a protective cuticle

In protostome development, which feature is characteristic?

• Blastopore becomes the anus during gastrulation

• Indeterminate cleavage and radial cleavage dominate

• Coelom forms by enterocoely in all lineages

• Blastopore becomes the mouth during gastrulation

Ecdysozoa is primarily distinguished by which trait?

• Having a water vascular system for locomotion

• Molting a cuticle that serves as an exoskeleton

• Ciliated larvae with trochophore life stages

• Possessing a notochord during early development

Which combination correctly matches a flatworm system with its status?

• Excretory system absent lacking flame cells

• Circulatory system closed with multiple hearts

• Respiratory system absent relying on diffusion

• Digestive system complete with separate anus

Among Platyhelminthes, which class entirely lacks a digestive system?

• Trematoda with multi‑host internal parasites

• Cestoda with tapeworms using a scolex

• Monogenea with external fish parasites

• Turbellaria with free‑living benthic species

Gas exchange in many annelids occurs primarily through which surface?

• Tracheal exchange via spiracle openings

• Book lungs with lamellar chambers

• Gill exchange using ctenidia surfaces

• Cutaneous exchange across moist skin

Which annelid subgroup is defined by a clitellum and includes earthworms and leeches?

• Oligochaeta with dorsal parapodia and cirri

• Hirudinea with parapodia and chitinous jaws

• Clitellata with mucus‑secreting reproductive ring

• Polychaeta with parapodia and many chaetae

Which statement about earthworms (Oligochaeta) is accurate?

• Use anterior jaws to feed as blood parasites

• Lack a coelom and are primarily acoelomate

• Have reduced setae and improve soil structure

• Possess numerous parapodia for rapid swimming

Which trio represents the shared body plan components of most mollusks?

• Foot, visceral mass, and mantle

• Scolex, proglottids, and hooks

• Setae, parapodia, and clitellum

• Book lungs, tracheae, and spiracles

Which statement about molluscan feeding is correct?

• Bivalves and gastropods both lack radulae

• All groups lack radulae and filter feed

• Cephalopods uniquely lack hardened beaks

• Most have a radula for scraping surfaces