[A] : Placenta is a tissue in eutherian mam- mals that has both embryonic and maternal tissue.
[R]: In mammals, foetal components of the placenta derive from trophoblast.

Assertion : In placental mammals the placenta is connected to the embryo by the umblical cord and has an essential role in the immunological protection of the embryo . Reason : In mammals foetal components of the placenta derive initially from the chondroblast connected with embryonic derive initially from he chondroblast connected with embryonic blood stream either through its contact with the yolk sac.

Assertion : In placental mammals the placenta is connected to the embryo by the umblical cord and has an essential role in the immunological protection of the embryo . Reason : In mammals foetal components of the placenta derive initially from the chondroblast connected with embryonic derive initially from he chondroblast connected with embryonic blood stream either through its contact with the yolk sac.

Assertion : In placental mammals the placenta is connected to the embryo by the umblical cord and has an essential role in the immunological protection of the embryo . Reason : In mammals foetal components of the placenta derive initially from the chondroblast connected with embryonic derive initially from he chondroblast connected with embryonic blood stream either through its contact with the yolk sac.

Assertion : In placental mammals the placenta is connected to the embryo by the umblical cord and has an essential role in the immunological protection of the embryo . Reason : In mammals foetal components of the placenta derive initially from the chondroblast connected with embryonic blood stream either through its contact with the yolk sac.

The word tissue has derived from

Connective tissues are derived from embryonic

Connective tissues are derived from embryonic