Asexual - sexual reproduction

Explain the following concepts:
Asexual - sexual reproduction.
Mitosis – Meiosis
Diploid - Haploid
Gametes
Fertilization
Zygote
Syngamy
Blastocyst
Implantation
Gastrulation
Embryo - Fetus
Explain fertilization process from cellular level to fetus (as per video time 1:08:00)
After learning about fertilization process, and according to nature and objectively, and scientifically speaking, when does human life begin? Why?