1. The male gamete (sperm) fuses with the female gamete (ova/egg) during fertilization to form a zygote. 2. The zygote develops into an embryo, which implants in the uterus and develops further into a fetus through the roles of the placenta and umbilical cord. 3. Childbirth occurs when contractions push the baby through the birth canal, after which the placenta detaches from the uterus and is delivered.

1. Reproduction in Humans

2. Human Reproductive
• Sexual Reproductive.
• Male gamete fuses with female gamete to form a zygote

3. The structure and functions of the male and
female human reproductive systems
• Female

4. Thumbnail.

5. The structure and functions of the male and
female human reproductive systems
• Female
• OVARIES
• Two ovaries contain ova (eggs). Ova = female gametes
• Women have these cells in their bodies from birth, whereas men
produce new sperm continually = meaning once the ova are finished,
the female can no longer reproduce

6. The structure and functions of the male and
female human reproductive systems
• Female
• OVARIES
• Two ovaries contain ova (eggs). Ova = female gametes
• Women have these cells in their bodies from birth, whereas men
produce new sperm continually = meaning once the ova are finished,
the female can no longer reproduce

8. The structure and functions of the male and
female human reproductive systems
• Female
• OVIDUCTS or FALLOPIAN TUBES
• From each ovary is an oviduct/fallopian tube.
• The oviduct is lined with ciliated cells. Every month, an ovum (egg)
develops and becomes mature, and is released from an ovary. The
cilia move the ovum along the oviduct and into the uterus.

10. The structure and functions of the male and
female human reproductive systems
• Female
• UTERUS or WOMB
• The uterus is a muscular bag with a soft lining.
• It is where a baby develops until its birth.
• The cervix is a ring of muscle at the lower end of the uterus. It keeps
the baby in place while the woman is pregnant.

12. The structure and functions of the male and
female human reproductive systems
• Female
• VAGINA
• The vagina is a muscular tube that leads from the cervix to the
outside of the woman's body.
The bladder opening, urethra, it is separate from the vagina. It passes
urine out of the body from the bladder.

14. The structure and functions of the male and
female human reproductive systems
• Male

16. The structure and functions of the male and
female human reproductive systems
• Male
• SPERM DUCT and GLANDS
• The sperm pass through the sperm ducts, and mix with fluids
produced by glands.
• The fluids provide the sperm cells with nutrients. This mixture is
called semen.

18. The structure and functions of the male and
female human reproductive systems
• Male
• SPERM DUCT and GLANDS
• The sperm pass through the sperm ducts, and mix with fluids
produced by glands.
• The fluids provide the sperm cells with nutrients. This mixture is
called semen.

20. The structure and functions of the male and
female human reproductive systems
• Sperm Production
• Sperm develop in the testis, by meiosis.
• From puberty, sperm is produced continuously until death.
• QUESTION?
• Why are the testes on the outside of the body?
• Sperm production is sensitive to heat. Too hot and cells will
not develop.

21. The structure and functions of the male and
female human reproductive systems
• Egg Production
• Girl is already born with all her eggs. At puberty, some begin to
mature. (one at a time)
• Ovulation = when the egg is mature, it will burst from the ovary into
the oviduct.
• PUBERTY = "stage of development during which sexual maturity is
reached"

22. Fertilization and development of the embryo
• Fertilisation is the fusion of the nucleus of a male gamete with the
nucleus of a female gamete, producing a new cell called a zygote. This
then matures into an embryo.

24. Fertilization and development of the embryo
• Fertilisation
• The egg is released from the ovary and moves toward the oviduct.
• A sperm has been ejaculated into the vagina and is travelling up the
cervix. (Using their tails to swim)

25. Fertilization and development of the embryo
• Fertilisation
• The egg and sperm meet at the oviduct and the process of
fertilisation begins.
Only the head of the
one sperm enters the egg.
After entry, the egg
membrane becomes
impenetrable to other sperm

27. Fertilization and development of the embryo
• Fertilisation
• Now a zygote has formed.
• The zygote moves slowly down the oviducts. Dividing by mitosis, to
form an embryo.
• NB. Cilia in oviduct "sweep" the embryo along the tube. (peristalsis)
• EMBRYO = an immature organism before all the organs have formed
• This embryo is fed from yolk of the egg.

28. Fertilization and development of the embryo
• Implantation
• After several hours, the embryo reaches the uterus
• It sinks into the spongy lining of the wall.

30. The roles of the placenta
• The Placenta
• After fertilisation, the newly-formed zygote divides repeatedly to
form a ball of cells called an embryo. This becomes implanted in the
wall of the uterus.
• After 11 weeks of development, the embryo is called a fetus. The
amniotic sac produces amniotic fluid, which surrounds and protects
the developing embryo.

32. The roles of the placenta
• The Placenta
• A placenta, connected by an umbilical cord, develops from the
embryo. The placenta anchors the embryo in the uterus.
• Umbilical cord:-
• nutrients and oxygen to move from the mother to the embryo
• waste materials and carbon dioxide to move from the embryo to the
mother
• There is no connection between the circulatory systems of the
embryo and its mother, so their blood doesn’t mix.
• (Separated by the placenta wall)
• These materials pass from one to the other by diffusion. (wall is thin)

34. The roles of the placenta
• The Placenta
• As the fetus grows, so does the placenta
• At birth the placenta is a flat disc 12cm x 3cm

36. The roles of the placenta
• Development of the embryo/fetus
• Zygote Embryo Fetus
• At fertilisation Simple ball of cells Cells develop into different types
(identical cells) (10-11 Weeks, all organs in place)
(6 Weeks, organs begin to form)
(8 Weeks, muscles move)
(10-38 Weeks, continues to develop)
(38 Weeks, ready to be
born)

38. The roles of the placenta
• BIRTH
• Birth begins with strong
muscle contractions in uterus
wall. Stretching the cervix
open.
• Amniotic sac breaks
When cervix is wide enough,
muscles push the baby down
through the cervix and out of the
vagina
The baby is still attached by the
umbilical cord and
placenta. Placenta no longer
needed (baby can breath for
itself)
The placenta detaches from the
uterus wall and passes through
the vagina (afterbirth)
Umbilical cord is cut, painless
because there are no
nerves. Stump forms the baby's
navel
A few weeks before birth the
fetus usually turns over, so head
is next to cervix

39. The roles of the placenta
• BIRTH
• Birth begins with strong
muscle contractions in uterus
wall. Stretching the cervix
open.
• Amniotic sac breaks
When cervix is wide enough,
muscles push the baby down
through the cervix and out of the
vagina
The baby is still attached by the
umbilical cord and
placenta. Placenta no longer
needed (baby can breath for
itself)
The placenta detaches from the
uterus wall and passes through
the vagina (afterbirth)
Umbilical cord is cut, painless
because there are no
nerves. Stump forms the baby's
navel
A few weeks before birth the
fetus usually turns over, so head
is next to cervix

40. • 1 Which statement about sex cells is correct?
• Sperm are male gametes
• Ova are male gametes
• Sperm are female gametes
• 2 In reproduction, what is fertilisation?
• When a male and female gamete join
• When a farmer puts manure on farmland
• When plants drop seeds onto the ground
QUESTIONS

41. • 3 What is a zygote?
• A cell formed when two embryos join, which will develop into a gamete
• A cell formed when two gametes join, which will develop into an embryo
• A cell formed when two gametes join, which will develop into a gland
• 4 Which of the following is not a part of the male reproductive system?
• Penis
• Testes
• Uterus
QUESTIONS

42. • 5 Where are the female sex cells contained?
• In the uterus
• In the ovaries
• In the ova
• 6 What is ovulation?
• The release of a mature egg cell
• The loss of the lining of the uterus
• The joining of a male sex cell and a female sex cell
QUESTIONS

43. • 7 Which way does blood normally pass across the placenta?
• From the mother to the foetus
• From the foetus to the mother
• Blood does not pass across the placenta
QUESTIONS