A student observes a wormlike organism crawling about on dead organic matter. Later, the organism sheds its outer covering. One possibility is that the organism is a larval insect (like a maggot). However, it might be a member of the phylum ________, and one way to distinguish between the two possibilities is by looking for ________.
A) Platyhelminthes; a cuticle of chitin
B) Nematoda; an alimentary canal
C) Annelida; a body cavity
D) Nematoda; a circulatory system
E) Annelida; muscle in the body wall
Organic molecules
Organic Fertilizer
Organic-rich marine clays
Chemical, Biochemical, and Organic Sedimentary Rocks
Medial view of tracts revealed by removing gray matter from a midsagittal section
The developing organism senses maternally transmitted environmental cues