Question

Villi are present on the embryo side of placenta. Which of the following will be functions of it?

• A. Provides a large surface area for glucose and oxygen to pass.
• B. Provides a large surface area for oxygen to pass.
• C. Helps to provide signals to brain.
• D. Waste substances can be removed

Answer 1

Answer: (A), (B), (D)

Waste substances can be removed

The embryo gets nutrition from the mother’s blood with the help of a special tissue called placenta. This is a disc which is embedded in the uterine wall. It contains villi on the embryo’s side of the tissue. On the mother’s side are blood spaces, which surround the villi. This provides a large surface area for glucose and oxygen to pass from the mother to the embryo. The developing embryo will also generate waste substances which can be removed by transferring them into the mother’s blood through the placenta.