What are the stages of development between conception and birth?(1.1) Conception: Conception takes place in the fallopian tube and one egg and one sperm fuse; however for non identical twins two sperm and two eggs fuse and for identical twins one egg and one sperm fuse and then split. Within around 24 hours of fertilisation the cell splits into two and continues to divide in twos during the journey to the uterus which happens around three to four days after fertilisation. First four weeks: During the first four weeks the cluster of cells implants itself in the wall of the uterus. The placenta starts to grow (two way growth) the amniotic sac forms and the yolk sack forms which allows blood vessels for the foetus and the placenta join the yolk sack also contains nutrients. The cells continue to divide and they start to develop specialism’s for example: 7 weeks: …show more content…
However, at this stage they are just starting to sprout and grow longer and do not yet look like limbs yet. The head is also enlarging during this week as well as the spinal column starting to develop with nerves. The brain and organs start to grow and body systems such as blood vessels and the nervous system start to develop. During this time the brain is starting to develop individual areas, the eyes and ears are also starting to take shape; the heart will also begin to