DEVELOPMENT
AND GESTATION
, FERTILIZATION
DURING COPULATION (SEXUAL INTERCOURSE) THE PENIS IS INSERTED INTO
THE VAGINA AND SPERM CELLS ARE RELEASED THROUGH EJACULATION
CLOSE TO THE CERVIX. THE SPERM CELLS SWIM THROUGH THE CERVIX UP
INTO THE UTERUS AND THROUGH THE FALLOPIAN TUBES.
THE HAPLOID OVUM RELEASED DURING OVULATION ENTERS THE
FALLOPIAN TUBES. IF AN OVUM (HAPLOID) IS PRESENT IN THE FALLOPIAN
TUBES, ONE SPERM CELL (HAPLOID) MAY PENETRATE THROUGH THE
JELLY LAYER AND FERTILISE THE OVUM RESULTING IN A DIPLOID ZYGOTE.
THE NUCLEUS OF THE OVUM AND THE NUCLEUS OF THE SPERM CELL
FUSE RESULTING IN FERTILISATION.