Which of the following events is involved in the cleavage of the zygote during week 1 of development（）
A. Production of highly differentiated blastomeres
B. An increased cytoplasmic content of blastomeres
C. An increase in size of blastomeres
D. A decrease in size of blastomeres
查看答案
Where do primordial germ cells initially develop（）
A. In the gonads at week 4 of embryonic development
B. In the yolk sac at week 4 of embryonic development
C. In the gonads at month 5 of embryonic development
D. In the gonads at puberty
Where does the blastocyst normally implant（）
A. Functional layer of the endometrium
Basal layer of the endometrium
C. Myometrium
D. Perimetrium
Which of the following components plays the most active role in invading the endometrium during blastocyst implantation（）
A. Epiblaslt
B. Syncytiotrophoblast
C. Hypoblast
D. Extraembryonic somatic mesoderm
Which principle of spiral CT scanning is correct（）
A. The tube rotates and the bed moves simultaneously
B. The tube rotates and the bed is stationary
C. The tube is fixed and the bed moves continuously
D. The tube rotates first and then the bed moves
E. The tube and the bed are both fixed
微信支付 
支付宝支付