Answered

Get the answers you need at Westonci.ca, where our expert community is always ready to help with accurate information. Ask your questions and receive detailed answers from professionals with extensive experience in various fields. Explore comprehensive solutions to your questions from a wide range of professionals on our user-friendly platform.

The correct order of the process that occurs when a sperm encounters an egg is the a. sperm reaches ovum, zona pellucida dissolves, zygote is formed, implantation occurs, and the embryo begins secreting hCG. b. zona pellucida dissolves, sperm reaches ovum, zygote is formed, implantation occurs, and the embryo begins secreting hCG. c. zona pellucida dissolves, sperm reaches ovum, zygote is formed, embryo begins secreting hCG, and implantation occurs. d. sperm reaches ovum, zygote is formed, implantation occurs, zona pellucida dissolves, and the embryo begins secreting hCG. e. sperm reaches ovum, zona pellucida dissolves, zygote is formed, embryo begins secreting hCG, and implantation occurs.

Sagot :

ajinems

Answer: The option with the correct order is D and it includes:

--> sperm reaches ovum,

--> zygote is formed,

--> implantation occurs

--> zona pellucida dissolves,

--> and the embryo begins secreting hCG.

Explanation:

In humans, the male ejects sperms with great force into the cervix and the upper part of the vagina of the female. The sperms move rapidly through the cervix and the uterus into the upper part of the oviduct ( the fallopian tube) where it REACHES THE OVUM.

There are follicle cells and the zona pellucida which surrounds the ovum. The acrosomal lytic enzymes in the head of the sperm can dissolve the cell wall and membranes. They help the sperm to move through the follicle cells that surrounds the ovum and penetrate the zona pellucida of the ovum. The sperm them moves into the ovum. The nucleus of the sperm fuses with that of the ovum to FORM A DIPLOID ZYGOTE.

The zona pellucida undergoes some changes that prevents other sperm from penetrating the ovum. It continues to protect the zygote as it travels through the fallopian tube to the uterus, the site for implantation. Around 72 hours after fertilization, IMPLANTATION OCCURS and the ZONA PELLUCIDA FRAGMENTS AND DISSOLVES.

Soon after implantation, the embryo begins secreting Human chorionic gonadotrophin (HCG) through the trophoblast cells which surround the developing embryo. It is the embryonic hormone that ensures the corpus luteum continues to produce progesterone throughout the first trimester of pregnancy.

Thank you for your visit. We are dedicated to helping you find the information you need, whenever you need it. We appreciate your time. Please come back anytime for the latest information and answers to your questions. Your questions are important to us at Westonci.ca. Visit again for expert answers and reliable information.