Several Pseudocoelomate Groups Have a Constant Number of Cells or Nuclei

Q5: The free-swimming,ciliated stage that hatches from a

Q9: Since flatworms and ribbon worms lack a

Q18: Mesodermal cells,known as _ cells,fill the space

Q19: In flame cells<br>A)flagella drive fluid through tubules.<br>B)digestion

Q20: People become infected with Schisitosoma when _

Q21: An organism with three distinct germ layers

Q23: Rotifers<br>A)are primarily marine.<br>B)are dioecious.<br>C)lack an excretory system.<br>D)lack

Q24: The flatworms are more derived (or advanced)than

Q26: The mastax of a rotifer is used

Q27: In contrast to other flatworms,tapeworms lack a