Identify the structures which have the potency to give rise to all the tissues and organs.
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Stem cells
In early embryonic development the blastocyst has an outer layer, the trophoblast, and an inner cell mass. The inner cell mass contains stem cells.
(1) Stem cells — Correct. They can form every tissue and organ.
(2) Trophoblast — Incorrect. It is the outer layer of the blastocyst. It attaches the embryo to the uterus and forms the chorionic villi, and it does not form the tissues of the body.
(3) Chorionic villi — Incorrect. These are finger-like projections of the trophoblast. They fit into the uterine tissue to form the placenta.
(4) Placenta — Incorrect. It is the link between the embryo and the mother. It carries food and oxygen and takes away waste. It also makes hormones, but it is not the source of the embryo’s tissues.
NCERT Extract:
Pregnancy and Embryonic Development – “… Immediately after implantation, the inner cell mass (embryo) differentiates into an outer layer called ectoderm and an inner layer called endoderm. A mesoderm soon appears between the ectoderm and the endoderm. These three layers give rise to all tissues (organs) in adults. It needs to be mentioned here that the inner cell mass contains certain cells called stem cells which have the potency to give rise to all the tissues and organs.”