Question

12.11 leeches lack setae but have suckers for attaching and feeding off their hosts. check your progress 4.1 what anatomical similarities do you see among leeches, earthworms, and sandworms? 4.2 do leeches possess setae? how do they move? 4.3 what is the function of the anterior sucker? the posterior sucker? 4.4 in what ways are the movements of leeches and earthworms similar? in what ways do their movements differ?

Explanation:

4.1 All three are annelids. They have segmented bodies, a coelom (body - cavity), and a complete digestive system with a mouth and anus.
4.2 Leeches lack setae. They move by using their anterior and posterior suckers to attach and detach from surfaces, and by contracting their body muscles to crawl or swim.
4.3 The anterior sucker is used for feeding, grasping the host, and sometimes for sensing. The posterior sucker is mainly used for attachment to the substrate or host, providing stability during feeding or movement.
4.4 Similarities: Both use muscle contractions for movement. Differences: Earthworms use setae for locomotion on land, while leeches use suckers; leeches can swim, while earthworms are mainly terrestrial crawlers.

Answer:

4.1 They have segmented bodies, a coelom, and a complete digestive system with a mouth and anus.
4.2 No, they move using anterior and posterior suckers and body - muscle contractions.
4.3 Anterior sucker: for feeding, grasping, sensing; Posterior sucker: for attachment.
4.4 Similarities: Use muscle contractions. Differences: Earthworms use setae, leeches use suckers; leeches can swim, earthworms are mainly terrestrial crawlers.