2. Human reproduction
@Human beings, reproduce by sexual reproduction.
@ Sexual reproduction is how human beings have children.
This process involves the combination of female and male
reproductive cells.
SEX CHARACTERISTICS
There are physical differences between male and
female bodies.
HUMAN REPRODUCTIVE CELLS
There are two types of human reproductive cells: the female egg cell
(ovum) and the male sperm cell(spermatozoon). Both types of
reproductive cells are also called gametes.
3. Most girls go through puberty
Between 10 and 14 years.
Most boys go through puberty
Between 11 and 16 years.
SEX CHARACTERISTICS
PRIMARY SEX
CHARACTERISTICS
@Are physical differences
between male and female
reproductive organs.
SECONDARY SEX
CHARACTERISTICS
@Are physical differents
that aren't directly related to
reproduction. These
characteristics start
appearing during puberty.
4. GIRLS
During puberty, a
girl’s breasts get
larger.
Her body gets
rounder and her
hips get wider.
Body hair grows
under her arms
and in her pubic
area.
BOYS
During puberty, a
boy’s voice gets
deeper.
His muscles get
larger and his
shoulders get
wider.
Body hair grows
under his arms, on
his chest, in the
pubic area and in
his face.
5. MALEFEMALE
@ Produces sperm cells in
the testicles.
@ During puberty, a boy’s
body stars to produce
male gametes. His
testicles produce
millions of sperm cells
all the time. This
process doesn’t stop at
any particular age.
@ Produces egg cells in the
ovaries. (two ovaries).
@ During puberty, a girl’s
body starts to produce
female gametes. Every 28
days, one of her ovaries
releases a mature egg
cell. This process usually
stops when a woman is
between 45 and 55 years
old.
8. An egg cell starts to
mature inside one of
the ovaries. On the
14th day the egg cell
leaves the ovary. This
process is called
ovulation.
The walls of the uterus
become thicker with
extra tissue and blood.
This change prepares
the uterus for a
fertilised egg cell, the
extra tissue and blood
come away from and
leave the body
through the vagina.
This process is called
menstruation.
Starting from puberty, a woman’s ovaries and uterus perform a regular
series of activities every 28 days.
9. The male reproductive system produces male gametes, called sperm
cells. It also transports the sperm cells out of a man’s body and into a
woman’s reproductive system.
10. The male reproductive system becomes
mature during puberty. Then the testicles
start to produce millions of sperm cells.
1. …….
2. …….
3. …….
4. …….
11. FERTILISATION
When a sperm
cell fertilises an
egg cell, the
two cells join to
form a new cell
called a
zygote. Then
the zygote
develops into a
fetus.
PREGNANCY
Is the time
between the
fertilisation of
an egg cell
and the birth
of a baby.
BIRTH
•Iwhen the
baby leaves
the uterus
through the
vagina. Birth
happens in
three stages:
the dilation of
the cervix, the
expulsion of
the baby and
the expulsion
of the
afterbirth.
12. Sexual intercourse: the man deposits his
semen into the woman’s vagina. The
sperm cells go up the fallopian tubes,
only one of them joins the egg cells and
form a zygote. The zygote travels to the
uterus and after six days the zygote
transforms into an embryo.
13. It lasts for about nine months. During this
time, two special organs form inside the
uterus: the placenta and the amniotic sac.
The fetus is connected to the placenta by
the umbilical cord, it provides the oxygen
and nutrients and it also takes away carbon
dioxide and waste that the fetus produces.
The amniotic sac is a bag of tissue that
contains amniotic fluid. This liquid supports
the fetus and protects it from impacts and
vibrations.
14. 1. The walls of the uterus starts to contract in a
rhythmic way and the cervix dilates.
Then the amniotic sac breaks and the
contractions push the baby into the vaginal
canal.
2. The baby is expelled through the vagina. After
that, the baby starts to breathe. The doctor cuts
the umbilical cord.
3. The uterus contracts again and the afterbirth is
expelled. The afterbirth includes the placenta, the
amniotic sac and the rest of the umbilical cord.
