The one-cell zygote, traveling slowly down the fallopian tube towards the uterus, begins to duplicate and multiply. At about the eight-cell stage, the process of differentiation begins, early cells take on distinct characteristics and move toward particular locations, foreshadowing the types of cells they will become. These early cells, capable of becoming any part of an organism, are known as:.

Embryonic Stem cell

Explanation:

Stem cells are the multipotent cell which can give rise to a variety of other cells and can form different tissues. The stem cells are present in the embryo and the well-developed adult organism, therefore, is known as the embryonic stem cell and the adult stem cell.

In the given case, after the blastocyst stage of embryo is formed, the cells present in the inner side of the blastocyst possess the ability to form different organs and therefore are called embryonic stem cells.

Thus, embryonic stem cell is correct

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.