QUESTION 4 Describe the events that lead to pregnancy from the time a zygote is formed, up to the formation of the foetus including the development of the placenta and umbilical cord. Content: Synthesis:

Once a zygote is formed, typically after the sperm fertilizes the egg, it begins to divide rapidly in a process called cleavage as it travels down the fallopian tube. This leads to the formation of a blastocyst, which implants itself into the uterine lining around six to ten days post-fertilization. As the blastocyst implants, it starts developing into an embryo, and a placenta begins to form. This remarkable organ not only nourishes the growing embryo but also connects it to the mother via the umbilical cord, allowing the exchange of essential nutrients, gases, and waste products. Through this incredible journey, the embryo undergoes several key developments, morphing into a fetus by the end of the eighth week. During this time, vital structures like the heart, brain, and limbs begin to take shape. The placenta becomes fully functional by the end of the first trimester, playing a crucial role in supporting the fetus for the remainder of the pregnancy, all while the umbilical cord ensures a continuous supply of oxygen and vital nutrients. It’s a fascinating dance of biology that results in new life!