Question

Number of foetal membranes in humans is?

• A. $2$
• B. $3$
• C. $4$
• D. $1$

Answer 1

The correct option is C $4$

Foetal membranes present in humans are the amnion, chorion, allantois and yolk sac.

Amnion is the innermost layer that surrounds the embryo and is filled with the amniotic fluid that absorbs the shock and protects the embryo from mechanical stress

The chorion is the outermost layer that is composed of trophoblast cells and mesoderm, it is responsible for the formation of the placenta.

The allantois is reduced in nature. It is present as a bag like structure near yolk sac.

The yolk sac had a nutritive function in reptilia, aves and other egg-laying mammals but in humans, these are done by the placenta. Yolk sac act as a precursor for blood cells.

So, the correct option is '4'