Because things take time to grow
If the sperm cell fertilises the ovum, and implantation does not occur, then the corpus luteum degenerates and it turns into corpus albicans, stopping progesterone secretion. If fertilisation occurs and implantation also, the syncytiotrophoblast, the "root part" of the blastocyst (one of the early structures originated from the zygote), produces a hormone that is called <span>human chorionic gonadotropin (hCG). The hCG is what makes the corpus luteum keep secreting progesterone and maintain itself. The progesterone will then help keep the endometrium and, therefore, allow the development of the embryo to happen.</span>
Answer:
False
answer is FALSE. Metals are usually good conductors, while nonmetals are not usually good conductors.
Explanation:
hope it helps
The Precambrian eon is separated from the Phanerozoic eon in the fossil record because of the sudden appearance of organisms.
Explanation:
Precambrian eon is the initial existence on earth that can be predicted by the study of rocks and remaining of fossils. It has been seen as the existence of skeleton in this era, before this era no such things has been observed, even the development of sexual reproduction.
The Phanerozoic era comes after the Precambrian era, more advanced kinds of fossils of animals had been observed in this era. Phanerozoic era period of life on earth. Large organisms sudden appearance are seen in the Phanerozoic era i.e. First dinosaurs, mammals, fishes, angiosperms,first vertebrates etc.
<span>peristalsis should be your answer.</span>
