List the defining characteristics for each class of annelid

Help me to understand this videos to answer some questions:

Phylum Porifera: https://www.shapeoflife.org/video/sponges-origins (14:02)1. In what ways are sponges like other animals?2. What do the spicules do for the sponge?3. How is the sponge’s pump powered?4. List two “firsts” in the animal kingdom that the sponge can claim.5. What are the defining characteristics of the phylum Porifera?Phylum Cnidaria: https://www.shapeoflife.org/video/cnidarians-life-... (14:44)1. How do tentacles give a cnidarian an advantage?2. What two digestive system structures appeared first in the cnidarians?3. How do nerve cells work with muscle cells to give the cnidarian movement?4. What characteristics of nematocysts make them effective for hunting and defense?5. Name and describe the two different versions of the cnidarian body plan.Phylum Platyhelminthes: https://www.shapeoflife.org/video/flatworms-first-... (9:54)1. Draw a quick sketch of the central nervous system of a flatworm.2. Name two anatomical features that appeared on the flatworm before any other animal.3. What are two features of the flatworm’s eye?4. What are some features shared by both flatworms and modern mammals and reptiles?5. What are the advantages and disadvantages of being a hermaphrodite?Phylum Annelida: https://www.shapeoflife.org/video/annelids-powerfu... (13:38)1. How does the feather duster worm detect danger?2. Name three features of an annelid that are parallel with human features.3. What do the tubes built by Diopatra do for the estuary?4. What service do annelids provide for planet Earth?5. What are the advantages of having a segmented body?