1. life cycle of humans infant (baby) sex cells gametes child adult
adolescent (teenager)

2. Puberty
The time when an individual changes from a child to a mature adult.
Puberty starts when the girls are about 11 years old and the boys are about 13 years old.
The puberty brings physical and emotional changes in both sexes.
Physical changes that happen to both: sex hormones are released into blood, growth spurt (growing tall in short period of time).
pubic hair grows, armpit hair grows
Physical changes that happen to boys only: penis grows bigger, sperm production starts, shoulders broaden, muscles grow stronger, voice breaks, facial and chest hair grows,
Physical changes that happen to girls only: breast develop, hips widen, menstruation starts once a month (bleeding period), mature egg is released from ovary once a month

3. sperm cell egg cell (ovum) jelly coat nucleus
Cytoplasm contains a store of food and energy
sperm cell
egg cell (ovum)

4. 1st phase: day 1-7. Menstruation-the old lining in the uterus (womb) breaks down and comes out of the vagina with blood
2nd phase: day The new lining builds up in the uterus and one egg matures in one of the ovaries
3rd phase: day 14. Ovulation- mature egg cell goes from the ovary to the oviduct (egg tube).
4th phase: day The lining of the uterus stays thick and waits for the fertilized egg.

5. male reproductive system

6. ejaculation – semen comes out of the penis in the top of the vagina

7. fertilisation – when egg and sperm join together
implantation – when embryo sinks into the lining of the uterus

8. embryo embryo fetus fetus 5 weeks old, 5 mm long, heart pumps blood
few hours after fertilization
size of a pinhead
fetus
10 weeks old
4 cm long, full set of organs
fetus
15 weeks old
mother can feel its movement

9. placenta
amnion
umbilical cord
amniotic fluid
baby (foetus)
womb (uterus)
cervix

10. Pregnancy – gestation period
Baby develops for about 40 weeks (9 months). This is known as gestation period.
The time when baby is born is called a labour. It has the following stages:
The uterus starts to contract (squeeze). The contractions become stronger as the labour progresses.
The cervix of the uterus widens (opens up).
The amnion breaks (sack that surrounds the baby) and amniotic fluid rushes out of vagina. This is known as water breaks.
Baby is born head first through vagina
The umbilical cord is cut. What remains of it forms navel (belly button)
Half an hour later the placenta comes out of the vagina. This is known as afterbirth.