Question

The following figure shows a foetus within the uterus. On the basis of the given figure, answer the questions that follow:

(a) In the above figure, choose and name the correct part (A, B, C or D) that act as a temporary endocrine gland and substantiate your answer. Why is it also called the functional junction?

(b) Mention the role of B in the development of the embryo.

(c) Name the fluid surrounding the developing embryo. How is it misused for sex-determination?

Answer 1

(a) Part labeled A -Placenta. It acts as an endocrine tissue as it produces several hormones like human chorionic gonadotropin (hCG), human placental lactogen (hPL), estrogens, progestogens, etc. It is also called the functional junction because it facilitates the supply of oxygen and nutrients to the embryo and removes carbon dioxide and excretory/waste materials produced by the embryo.

(b)The placenta is connected to the embryo through an umbilical cord which helps in the transport of substances to and from the embryo.

(c) Amniotic fluid; a foetal sex determination test is based on the chromosomal pattern of the cells in the amniotic fluid surrounding the developing embryo.