Puberty
❖ Puberty is the time when secondary sexual characteristics develop.
These characteristics prepare the body for sexual development.
Puberty usually signifies a time when an individual has reached
reproductive maturity, able to produce offspring.
❖ Puberty is when sex cells (gametes) are produced in males and those
in females mature or ripen.
❖ Male only PRODUCE sperm after puberty
❖ Female only RELEASE egg after puberty
Secondary sexual characteristics
Male (testosterone)
Female (Progesterone + Oestrogen)
1. Body hair grows
1. Breast development
2. Voice breaks
2. Hips widen
3. Muscle growth increases
3. Pubic + underarm hair
4. Sperm development
4. Menstruation
5. Skin may breakout
5. Skin may breakout
o Changes take place due to hormone activity
o During puberty – body secretes greater amounts sex
hormones These hormones
o Molecules which travel through blood, carry information/ produce
“instructions” for development secondary
o Ovaries stimulated release oestrogen + progesterone sexual
characteristics +
o Testes release testosterone regulate
o Rapid growth, skin problems, mood changes is result production
changes of levels of hormones gametes
,• The term reproduction refers to the production of offspring
• All living organisms reproduce in order to add individuals to
their population
• 2 ways in which organisms reproduce: some sexually, others
(many plants) asexually
• Some organisms able to reproduce both sexually and asexually
• When organisms reproduce asexually: “grow” from adult, similar
to cloning (all genetically same to parent). One
parent, without having sexual reproduction. E.g.
Violet plant, geranium
• Strawberry plant is both
• Some animals e.g. Amoebae reproduces asexually. Unicellular organism.
When reproduces
1.the nucleus makes copy of itself
2. The cytoplasm splits in two
3. 2 individual cells result.
• Hydra is another animal example of asexual
reproduction:
1. Cells on body increase quickly
2. Forming bulge which eventually grows tentacles
3. Young animal “drops off” parent able continue life separately.
• When animals reproduce asexually, live independently. No
time spending a mate. Offspring produced relatively
quickly.
❖ Sexual reproduction involves producing offspring as a result of
the fusion of gametes. Gametes are reproductive cells.
❖ Male= sperm cells
,❖ Female= egg cells
❖ Sperm cell has to fuse egg cell.
❖ Fertilization may take outside the body of female (external
fertilization)
❖ Or internally (internal fertilization) sperm placed as close to egg
as possible
❖ External fertilization in ocean threats:
Current, predators
❖ Yolk provides nourishment developing embryo to birds and
reptiles
❖ Placenta in mammals
Male reproductive system:
o Produces sperm cells in testes
o One testis on either side on either side of testis
o 2 testes – gonads, produce sperm
o Testes also produce male hormone testosterone, responsible
cause sperm cells to mature
, o Testis surrounds by thin skin called scrotal sac/ scrotum
o Since testes hang outside body, scrotum provides protection
against mechanical injury
o Scrotum main function: keep temp. below 37°(body temp.)
o Sperm cells not mature at body temp.
o Circumcision: The surgical removal of the foreskin, tissue
covering the tip of the penis
❖ Puberty is the time when secondary sexual characteristics develop.
These characteristics prepare the body for sexual development.
Puberty usually signifies a time when an individual has reached
reproductive maturity, able to produce offspring.
❖ Puberty is when sex cells (gametes) are produced in males and those
in females mature or ripen.
❖ Male only PRODUCE sperm after puberty
❖ Female only RELEASE egg after puberty
Secondary sexual characteristics
Male (testosterone)
Female (Progesterone + Oestrogen)
1. Body hair grows
1. Breast development
2. Voice breaks
2. Hips widen
3. Muscle growth increases
3. Pubic + underarm hair
4. Sperm development
4. Menstruation
5. Skin may breakout
5. Skin may breakout
o Changes take place due to hormone activity
o During puberty – body secretes greater amounts sex
hormones These hormones
o Molecules which travel through blood, carry information/ produce
“instructions” for development secondary
o Ovaries stimulated release oestrogen + progesterone sexual
characteristics +
o Testes release testosterone regulate
o Rapid growth, skin problems, mood changes is result production
changes of levels of hormones gametes
,• The term reproduction refers to the production of offspring
• All living organisms reproduce in order to add individuals to
their population
• 2 ways in which organisms reproduce: some sexually, others
(many plants) asexually
• Some organisms able to reproduce both sexually and asexually
• When organisms reproduce asexually: “grow” from adult, similar
to cloning (all genetically same to parent). One
parent, without having sexual reproduction. E.g.
Violet plant, geranium
• Strawberry plant is both
• Some animals e.g. Amoebae reproduces asexually. Unicellular organism.
When reproduces
1.the nucleus makes copy of itself
2. The cytoplasm splits in two
3. 2 individual cells result.
• Hydra is another animal example of asexual
reproduction:
1. Cells on body increase quickly
2. Forming bulge which eventually grows tentacles
3. Young animal “drops off” parent able continue life separately.
• When animals reproduce asexually, live independently. No
time spending a mate. Offspring produced relatively
quickly.
❖ Sexual reproduction involves producing offspring as a result of
the fusion of gametes. Gametes are reproductive cells.
❖ Male= sperm cells
,❖ Female= egg cells
❖ Sperm cell has to fuse egg cell.
❖ Fertilization may take outside the body of female (external
fertilization)
❖ Or internally (internal fertilization) sperm placed as close to egg
as possible
❖ External fertilization in ocean threats:
Current, predators
❖ Yolk provides nourishment developing embryo to birds and
reptiles
❖ Placenta in mammals
Male reproductive system:
o Produces sperm cells in testes
o One testis on either side on either side of testis
o 2 testes – gonads, produce sperm
o Testes also produce male hormone testosterone, responsible
cause sperm cells to mature
, o Testis surrounds by thin skin called scrotal sac/ scrotum
o Since testes hang outside body, scrotum provides protection
against mechanical injury
o Scrotum main function: keep temp. below 37°(body temp.)
o Sperm cells not mature at body temp.
o Circumcision: The surgical removal of the foreskin, tissue
covering the tip of the penis
