Natural Science
Module 8
, Stages of reproduction
● The human reproductive cycle begins with two mature adults – one male and one female.
● The adults undergo gametogenesis or the production of gametes.
● The male produces sperm cells and the female produces mature egg cells.
● Ovulation is the release of a mature ovum from the ovary into the fallopian tube.
● Once the ovum is in the fallopian tube, it needs to fuse with a sperm cell in order for the reproductive process to
continue.
● For this to happen, sperm cells need to enter the female body. This occurs through intercourse or sex. The erect male
penis is placed into the female vagina and semen is ejaculated into the female's body.
● The sperm cells are nourished and protected by the seminal fluids as they travel from the vagina, through the cervix,
and into the uterus.
● They then travel further, until they reach the waiting ovum in the fallopian tube. Fertilisation occurs when one sperm cell
fuses with the egg cell.
● The zygote moves through the fallopian tube with the help of the cilia, until it reaches the uterus 3 – 5 days later.
● The cells of the zygote continue to divide and once in the uterus, form a blastocyte which implants in the uterine wall.
● Implantation is complete 9 – 10 days after fertilisation has occurred.
● The blastocyte now develops into the embryo, within the amniotic sac, as well as the placenta.
● The placenta is an organ that develops during pregnancy and is attached to the wall of the uterus.
● The umbilical cord attaches the embryo to the placenta.
● It is the placenta that provides oxygen and nutrients to the growing embryo, and removes waste products from the
uterus.
● Eight weeks after fertilisation, the embryo becomes known as a foetus. Ten weeks after fertilisation, the foetus has fully
developed all of its organs with the exception of the brain and spinal cord. Twelve weeks after fertilisation, the sex of
the foetus can be determined. The foetus is born and then referred to as a baby, at around 40 weeks. Sometimes, the
foetus may be delivered early and this is when a premature baby is born.
Module 8
, Stages of reproduction
● The human reproductive cycle begins with two mature adults – one male and one female.
● The adults undergo gametogenesis or the production of gametes.
● The male produces sperm cells and the female produces mature egg cells.
● Ovulation is the release of a mature ovum from the ovary into the fallopian tube.
● Once the ovum is in the fallopian tube, it needs to fuse with a sperm cell in order for the reproductive process to
continue.
● For this to happen, sperm cells need to enter the female body. This occurs through intercourse or sex. The erect male
penis is placed into the female vagina and semen is ejaculated into the female's body.
● The sperm cells are nourished and protected by the seminal fluids as they travel from the vagina, through the cervix,
and into the uterus.
● They then travel further, until they reach the waiting ovum in the fallopian tube. Fertilisation occurs when one sperm cell
fuses with the egg cell.
● The zygote moves through the fallopian tube with the help of the cilia, until it reaches the uterus 3 – 5 days later.
● The cells of the zygote continue to divide and once in the uterus, form a blastocyte which implants in the uterine wall.
● Implantation is complete 9 – 10 days after fertilisation has occurred.
● The blastocyte now develops into the embryo, within the amniotic sac, as well as the placenta.
● The placenta is an organ that develops during pregnancy and is attached to the wall of the uterus.
● The umbilical cord attaches the embryo to the placenta.
● It is the placenta that provides oxygen and nutrients to the growing embryo, and removes waste products from the
uterus.
● Eight weeks after fertilisation, the embryo becomes known as a foetus. Ten weeks after fertilisation, the foetus has fully
developed all of its organs with the exception of the brain and spinal cord. Twelve weeks after fertilisation, the sex of
the foetus can be determined. The foetus is born and then referred to as a baby, at around 40 weeks. Sometimes, the
foetus may be delivered early and this is when a premature baby is born.
