Embryonic Development Research Paper

First, I want to convince embryo may not be a person. If “person” here, means biologically a member of human beings, then after 14 days when primitive streak or after 16 days when gastrulation (Damschen, Gómez-Lobo and Schönecker), an embryo is certainly a person, because at this point, the

1. These enzymes are used by the sperm to create an opening in the corona radiata, zona pellucida, and plasma membrane of the oocyte for the sperm to pass through

After embryo development, endosperm is growth to store nutrients. This happens after double fertilization, when the triploid nucleus of the ovule’s central cell divides. This causes the formation of a milky multinucleate “supercell”. This becomes multicellular after cytokinesis. Finally, when the cell walls are completed, the endosperm becomes solid.

Embryological Evidence – similarities in early embryos can indicate they came from a common ancestor.

A blastocyst is a ball of sixteen somatic cells that contains a thin spherical wall of cells surrounding a fluid-filled center which resembles a fluid-filled balloon. There are no organs or tissues at this stage and lacks a body plan. Eventually 9 six days after conception, the blastocyst attaches to the mom so it can join

S: Page 134 is all about the embryonic period of pregnancy. The embryonic period lasts from week 3 to week 8, and it is a very important time because that is when the ectoderm, mesoderm, and endoderm are being formed. The ectoderm, mesoderm, and endoderm will later for more important oragans and body structures.

Biological development of a fetus is vary rapid and complex over the nine-month period in the womb. When both the male spermatozoon and the female ovum combine it forms what is called a zygote which holds the twenty-three pairs of chromosomes. The zygote or the embryo undergoes cell division and makes its way to the uterine wall to implant itself, this process is completed about ten days after conception. By the end of the eighth week the organ systems have formed and human characteristics can start to be noticed. From the eighth week until birth the embryo is now labeled a fetus. Quickening can occur from the sixteenth week until birth, this is where the mother can feel the fetus moving. Around the twenty-second week viability can take place, this is where the fetus can survive outside the womb. The nine-month period of being pregnant is split into different trimesters. With the different trimesters there are different abortion procedures can be used to remove the fetus.

When an embryo becomes a fetus at eight weeks, it is approximately 3 centimeters; by the time the fetus is considered full-term, he or she may be 50 centimeters (Brisbane 60). The fetal stage, that takes place during week 9 to birth, result in a whole bunch of changes. (Brisbane 61). During the fetal stage, all parts of the body mature, and the overall of the baby size increases. Although all of the organ systems were formed during embryonic development, they continue to develop and grow during the fetal stage as well. During the third month, the reproductive system becomes developed and the sex of the baby becomes apparent (Staff). For girls, the ovarian follicles begin to form and for boys the prostate gland. Throughout months four through six, the heartbeat grows stronger and other body systems become further developed (Brisbane 63). Features such as fingernails, hair, eyelashes and toenails form. During the period from seven months until birth, the fetus continues to develop, put on weight, and prepare for life outside the womb (Brisbane 64). The lungs begin to expand and contract, preparing the muscles for breathing (Brisbane 64). The time in which the baby is born is a very critical. In some situations, a baby can be born as early as 7 months. When a baby is born too early, his ar her organs are not usually fully formed. This can result in many complications and health problems. Including, If premature pregnancy is the case, the baby would need some intensive care in hospitals. If the baby survives the stages, at the end of the nine month of pregnancy the baby will turn to a head-down position to prepare for birth. If the baby is not in the head-down position and in breech position a cesarean section may be required, which can cause many more complications. If a baby passes all these crucial factors, it is guaranteed to be born

Shortly after an egg is fertilized stem cells begin to form. These cells are programmed to form every organ and tissue in the body as the baby develops.

The author James Gallagher said “Over the course of the first seven days, a healthy, normal embryo goes from one cell to about 200. It also goes through the first steps of organizing itself and handing out specialized jobs to different cells”(BBC). James Gallagher used Logos in this quote to inform the reader of what normally happens in a human embryo.

    According to parents.com, after conception, a fetus begins to develop rather quickly. In the fifth week of pregnancy, a baby’s heart begins to beat. A baby also develops three distinct layers, ectoderm, endoderm, and mesoderm. These three layers will eventually form the body systems that are necessary

Important stages of pregnancy: Pregnancy is counted from the first day of the mother 's last period. Important development immediately takes place after fertilisation of egg and sperm cells. It divides into many cells in the first week, which forms a zygote made out of 100 to 150 cells that are already differentiating. In the second week, the zygote is then changed to an embryo and it sticks to the uterine wall. This process takes up to nine months to form and develop a baby.

[1] "Development of the embryo begins at Stage 1 when a sperm fertilizes an oocyte and together they form a zygote."

The fetal stage is the stage in which is marked by rapid growth and preparation

The development of the first stage is birth to 4 weeks. This point is likewise recognized as the Neonatal Period. Infant are held with a number of abilities that become the foundation of future growth.