Question

Create a timeline, which is formatted as a table or flowchart, that includes the following for all the essential reproductive milestones from conception to postnatal stages:

Describe the development milestones that occur in the stages of fertilization, embryonic development, fetal development, childbirth, and postnatal.

Include when each development milestone occurs.

Describe the key changes that happen within the child and mother during each milestone.

Highlight on your timeline when life begins, and provide your scientific rationale.

Answer 1

Stage	Milestone that occurs	Key change in child and mother
Fertilization	During the process of fertilization, there is fusion between the male and the female gamete. The egg and sperm fuse together and it tends to produce a diploid zygote. The zygote is single celled and further division takes place from here.	In this there is no visible change on the outside in the mother but there some key mechanism changes. Missed periods, increased level of progesterone and morning sickness are some of the early development in a mother.
Embryonic development	The embryonic development is basically the process where the embryo is developed. The embryonic development stage starts with cleavage of the zygote which forms the blastula. It has a fluid filled cavity and gradually this forms the gastrulation where the germ layers are developed. This is followed by 4th development stage of neuralation where the neural tube is formed.	In the baby, zygote divides and after moving into the uterus which starts with formation of 2 cells and gradually more till it forms blastomeres. The blastula is the stage of development where it forms hollow ball of cells and it is after 5 days of development. This is followed by gastrulation where the cells of the body develop into ectoderm, mesoderm and endoderm. In the mother, there is increased production of progesterone. There is maternal blood flow within uterus and the placenta helps in transferring nutrients with help of oestrogen.
Fetal development	The fetus development starts after almost 8thweek where it fills the whole of the uterus. The sex of the baby can be identified by 14 weeks and within 16 to 20 weeks, fetus can move.	In the fetus the sex organ starts developing in the child. It starts developing muscles, bone and organ system. The size of the brain also develops and the respiratory and digestive system starts working in the fetus independent of mother. During this the weight gain starts as the fetus occupies the uterus as it starts growing. Breast starts to grow for preparing lactation. There is heart burn, frequent urination, visible veins and also increasing mood swings.
Childbirth	During childbirth, when the baby is ready to come out the water bag that protects the child burst. This is an indication that the baby is ready to come.	During this the baby is fully developed and only the placenta is attached to the mother. The final days before the child birth, there are many physiological changes that take place. The level of progesterone drops during last final days and it causes contraction of uterine muscles that causes intense pain while delivery.
Post natal	The child gradually develops after the post natal phase and initially few months it feeds on only mother’s milk.	After birth, the placenta is removed on its own but due to the excess stretching it leaves a lot of stress marks. It is important that placenta is completely removed from system.