Compare and contrast the three phyla of worms. Which is ...

[Evvie72]

Compare and contrast the three phyla of worms. Which is considered to be the most evolutionarily advanced?

Question 2

A long-term effect of wave refraction is ____.
 A) to smooth and straighten a shoreline
  B) to add sediment to headlands that extend outward from the shore
  C) to erode and deepen bays
  D) to remove sand from the beach

[bfulkerson77]

Answer to Question 1

 Platyhelminthes are the flatworms. They are the simplest kind of worm. Some are parasitic, but most are free-living predators and scavengers. Flatworms are the first organism to have a primitive central nervous system. They also have small eyespots instead of a complex eye. Flatworms exchange gases through its skin because it lacks a true respiratory or excretory system.
 Nematodes are roundworms. They are the first worm to develop a digestive system. These worms are considered the most successful due to their representation in a variety of environments. They are especially successful in sediments. Most of these worms are free-living and microscopic.
 Annelids are segmented worms with a number of divisions. It allows for growth in the worm to occur in evenly spaced segments. Each segment contains its own circulatory, excretory, nervous, muscular, and reproductive system.
 Annelids are considered to be the most evolutionarily advanced worm.

Answer to Question 2

A