A Developmental Stage Comprised of a Hollow Ball of Cells

Q44: An enterocoelous animal has<br>A)a true coelom.<br>B)a pseudocoelom.<br>C)no

Q45: The nervous system of vertebrates develops from

Q46: The cortical reaction that follows fertilization causes

Q47: Entrance of more than one sperm<br>A)is called

Q48: The effect of yolk on cleavage is

Q50: The placenta develops from<br>A)fetal membranes only.<br>B)maternal tissue

Q51: A primitive streak appears during gastrulation of<br>A)sea

Q52: Throughout the descriptions of the various major

Q53: The difference between schizocoelous and enterocoelus organisms

Q54: Which of the following is NOT characteristic