Placenta is present in
All mammals
Metatherians
Eutherians
Prototherians
The embryo of man is protected by
External stimulus which induces cleavage in an unfertilized ovum is called
Seminiferous tubules develop central lumen after
Atretic follicles are found in the
In the fertile human female, approximately on which day of the menstrual cycle $(32\; days)$ does ovulation take place?