If your question is 'Is the trophoblast present during germ layer formation (i.e. gastrulation) ?' then the answer is YES
In humans, the outer layer of the blastocyst, called the trophoblast, secretes human chorionic gonadotrophin (hCG),human placental lactogen (HPL), and other hormones.
human chorionic gonadotropin (HCG)
Iron is a naturally occurring element, it is present in the human body, but the human body does not create it. It cannot be synthesised by any living being. Iron levels in the human body can be increased by eating iron rich foods and using supplements.
Vitamins are naturally occurring compounds present in most foods. The human body cannot produce vitamins and therefore has to acquire them from external sources: diet or supplements.
The sources of human capital formation under the creativity are education and health.The proper education and the proper maintenance of health and child birth can contribute towards human capital formation.
Propofol is not a naturally occurring substance in the human body.
Blastocyst formation
The difference between man made and natural occurring rock is that man made is something done by man (specification) human .We made it the way it seems ex.Mt Rushmore is man made because it wasn't naturally formed.Naturally occurring happens by flood, weathering ,deposition, and etc. It happens nautically no ones touched it. Another example is the Grand CanyonGlad i could help
No.
The acid present in the human stomach is gastric acid.
Ship yards are not naturally occurring so YES
There are 3 type of cartilage present in the human body