At what times after fertilization does the first cleavage of the zygote occur? Second? Third? What is the result called (8-cell)?
a) 12 hours; 24 hours; 36 hours; morula
b) 24 hours; 48 hours; 72 hours; blastocyst
c) 6 hours; 12 hours; 18 hours; gastrula
d) 36 hours; 72 hours; 108 hours; neurula