Question 1
The attachment of the zygote to the uterine wall is called:
◦ ovulation
◦ menstruation
◦ fertilization
◦ implantation
Question 2
The digestive system, lungs, and some other internal organs develop from which of the following layers of cells present in the embryo?
◦ ectoderm
◦ mesoderm
◦ endoderm
◦ zygoderm