For IGCSE O-Level Biology students Chapter 14

2.  To create a new human, a male sperm
must fuse (join) with a female egg.
 In any normal human cell there are 46
chromosomes; while in sperm and egg
cells there are only 23 chromosomes in
each.
 Upon fusion 46 chromosomes will be
present, this cell is now called a zygote.

3.  Sperm cells are much
smaller than egg cells.
 Sperms are produced in
the testis while eggs are
produced in the ovaries.
Head
Neck
Tail

4. Testosterone hormone
in males, produced in
testis cause the:
 Production of sperms.
 Growth of the
reproductive organs.
 Growth of body hair
 Increased muscular
growth, broadening of
shoulders
 Deepening of voice
 Growth of bones
Oestrogen hormone in
females, produced in
the ovaries cause the:
 Production of eggs.
 Growth of the
reproductive organs
 Beginning of menstrual
cycle
 Growth of hair
 Development of breasts
 Deposition of fats on
hips and thighs

5. is
penis
urethera

15. Breastmilk
 It contains easily digestible proteins.
 Breast milk contains antibodies which help
the baby to fight diseases.
 The breast milk has body temperature which
is suitable for the baby.
 Breast milk does not require sterilisation.
 Breast feeding creates a bond between the
mother and her baby.
Formulamilk
 Milk is modified to contain digested proteins
 Does contain antibodies
 Has to be adjusted to body temperature
 Requires sterilisation
 Can help a mother that cannot breast feed
due to illness to bond with baby.