Umbilical cord is a narrow, tube-like structure that connects the fetus to the placenta.Through this tube, nutrients and oxygen are supplied from the mother to the baby and waste products are removed from the baby.

Prolactin is secreted by the anterior lobe of pituitary gland. After parturition, secretion and storage of milk in mammary glands is under the influence of this hormone.

Placenta is an intimate connection between the fetus and uterine wall of the mother to exchange the materials. Food materials and oxygen pass from the mother's blood into the fetal blood and fetal excretory products diffuse into maternal blood through placenta.

The human placenta is both metadiscoidal and monodiscoidal. Discoidal refers to the structure of the placenta and mono meaning there is only one disc. Metadiscoidal refers to the way the developing placenta becomes discoidal- the villi are scattered at first and then restricted to one disc, that means the placenta becomes mono-discoidal.

The ductus arteriosus acts as a shunt between the pulmonary artery and the aorta during fetal development. In the fetus, before returning to the body, the blood is oxygenated in the placenta. Amniotic fluid fills the lungs and can not therefore be used to oxygenate the blood. Rather, the arterioles in the lungs restrict the quantity of blood flow that can pass through.

The placenta is formed from the chorion and allantois of the embryo and from the mother's endometrium. Its main function is to allow the exchange of substances between the fetus and the mother's body. 

The placenta is an organ, that connects the developing foetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply, fight against internal infection and produce hormones to support pregnancy. In humans, the placenta usually has a disc shape and it is formed by allantois, chorion and uterine wall.

The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination and gas exchange.
Ovary produces egg or ovum. Uterus is where implantation takes places and embryo develops. Vagina is the fibromuscular organ that facilitates sexual intercourse and childbirth.
Therefore, the correct answer is option A.

The placenta is the region which is the main connection between mother and child. It connects the umbilical cord of the developing foetus to the mother's uterine wall to perform several functions. It acts as a barrier between the mother and embryo. It helps in the nutrient uptake, waste elimination, thermoregulation and gas exchange in the foetus through the mother's blood supply. 

The placenta is an organ that develops in the uterus during pregnancy. This structure provides oxygen and nutrients to the growing baby and removes waste products from the baby's blood. The placenta attaches to the wall of the uterus, and the baby's umbilical cord arises from it. In most pregnancies, the placenta attaches to the top or side of the uterus. 

The placenta is an organ responsible for providing oxygen and nutrients to the fetus from the mother, and removing waste substances like urea from the fetus to the mother.

The mammals that show the presence of a placenta is called placental mammals. They are also called eutherians. Mongoose is a placental mammal. The placenta is the connection between the developing fetus to the mother's uterine wall. The placenta performs several functions such as nutrient uptake, waste elimination and gaseous exchange in the fetus through the mother's blood supply. Thus the correct answer is option D.

The placenta is an organ, that connects the fetus to the uterine wall. This allows the nutrient uptake, waste elimination and gas exchange via the mother's blood supply, fights against internal infection and produces hormones to support pregnancy. Placenta connects the fetus by an umbilical cord which contains two umbilical arteries and one umbilical vein. The placenta is encircled by a ring of smooth muscle cells.
The placenta does not have nerves.
Thus, the correct answer is option (D), 'Nerves'.

Trophoblasts are the cells forming the outer layer of a blastocyst, which provides nutrients to the developing embryo and it develops into a large part of placenta. Thus, trophoblasts are specialized cells of the placenta that plays an important role in embryo implantation.
Thus, the correct answer is option (A), 'Placenta'.

A placenta is formed from interdigitation of the trophoblast layer of the embryo and the endometrial lining during implantation. It facilitates the supply of oxygen and nutrients to the developing foetus and is also responsible for removal of carbon dioxide and excretory waste products of the foetus.

In humans, the placenta is chorionic in nature. It attaches the foetus and the mother and is responsible for the nutrition and excretion and exchange of gases.

After implantation, finger-like projections appear on the trophoblast called chorionic Villi which are surrounded by uterine tissue and maternal blood. The chronic villi and uterine tissue become interdigitated with each other and jointly form a structural and functional unit between developing embryo that is foetus and maternal body called placenta. Placenta facilitate the supply of oxygen and nutrients to the embryo and also helps in removal of carbon dioxide in excretory waste materials produced by the embryo.

The placenta in which the villi are restricted to a disk-shaped chorionic area on the ventral side of the embryo is known as the metadiscoidal placenta found in humans.

The haemochorial placenta is the type of placenta in which maternal blood is in direct contact with the chorionic villi which are covered by maternal blood and exchange of gases and nutrients from mother's blood and foetus takes place as observed in humans.

• Placenta is a special organ or tissue that connects the developing fetus to the uterine wall. It allows nutrient uptake, waste elimination, gas exchange via the mother's blood supply, fight against internal infection and produces a hormone to support pregnancy.

In the hematoendothelial placenta, the outer covering which is the trophoblast becomes so thin that it appears that the maternal blood is separated from the fetal blood only by a single layer of cells of the embryonic layer chorion. This type of placenta is generally found in Rat and rabbit.

The human placenta has chorionic epithelial cells. It has maternal endothelial cells of blood capillaries, maternal endometrial epithelium and endothelium of foetal blood capillaries. The foetal connective tissue surrounds the foetal endothelial blood capillaries. The maternal connective tissue surrounds the maternal blood capillaries. 

The placenta is an organ that develops in the uterus during pregnancy. This structure provides oxygen and nutrients to the growing baby and removes waste products from the baby's blood. The placenta attaches to the wall of the uterus, and the baby's umbilical cord arises from it. The organ is usually attached to the top, side, front or back of the uterus.

The placenta facilitates the supply of oxygen and nutrients to the embryo and also the removal of carbon dioxide and excretory/waste materials produced by the embryo. It is formed from the chorion.