Question

During implantation, the blastocyst is completely buried inside endometrium. This proves that human placenta is :

• A. Discoidal
• B. Interstitial
• C. Haemochorial
• D. Bidicoidal

Answer 1

Answer: (B)

Interstitial

In humans, a blastocyst implants completely inside the uterine epithelium. It remains in the endometrium throughout the entire development and is nourished by the cells of the endometrium. It is called as pregnancy implantation. This proves that human placenta is interstitial or deep. Discoidal placenta is a placenta in which the chorionic villi are arranged in a circular plate. In this, a single placenta is formed in discoid shape. In haemochorial placenta, maternal blood is in direct contact with the chorion.

Thus, the correct answer is option B.