write it in your own words:
"In humans, five days after the fertilization, the blastocyst performs zona hatching; the zona pellucida degenerates and decomposes, to be replaced by the underlying layer of trophoblastic cells. The zona pellucida is essential for oocyte growth and fertilization."
The zona pellucida supports communication between oocytes and follicle cells during oogenesis; protects oocytes, eggs, and embryos during development, and regulates interactions between ovulated eggs and free-swimming sperm during and following fertilization.
Answer:
The correct answer would be crawling and sucking reflex.
Crawling reflex is the reflex by which baby make crawling movements when placed on abdomen.
It helps in the baby to find his or her mother and food.
Sucking reflex helps the baby to eat food. Through this reflex, the baby starts sucking when area around the mouth is touched. For example, when the nipple is placed inside the mouth of the baby, he or she starts sucking.
<span>The fossils in the lower layers are older than the fossils in the upper layers.</span>
