Gametogenesis produces gametes having just a single complement of genetic material. Fertilization restores the full diploid genetic complement. Human embryogenesis is that period of human development between fertilization or implantation and the fetal phase of growth which starts in the ninth week of gestation.
Write down the processes and phases of human embryogenesis? Explain how does a fetus develop from a one-cell fertilized egg? What factors in the immediate environment of the embryo are needed to be present for normal embryo growth? Describe the factors which will disrupt this normal growth and cause problems?