Chapter 39: Reproduction,
Growth And Development
By
Mr. A. Rogan
Chapter 45: Reproduction,
Growth And Development
Introduction:
Male and female reproductive organs produce Sex cells
(Gametes).
Chapter 45: Reproduction,
Growth And Development
Female sex cell called the ovum or the egg.
Produced in the ovary
Ovum – 0.1 mm long
Chapter 45: Reproduction,
Growth And Development
Male sex cells are Sperm.
Sperm are produced in the testis
Sperm – 0.01 mm long
Chapter 45: Reproduction,
Growth And Development
Zygote – When an egg and a sperm fuse they form a zygote.
Zygotes develop into a new individual.
Chapter 45: Reproduction,
Growth And Development
Fertilisation:
Fertilisation is the fusion
(joining together) of an egg cell with a sperm cell.
Chapter 45: Reproduction,
Growth And Development
Chapter 45: Reproduction,
Growth And Development
Chapter 45: Reproduction,
Growth And Development
Male Reproductive
Parts:
Sperm Duct
Penis
Testis
Scrotum
Prostrate Gland
Urethra
Chapter 45: Reproduction,
Growth And Development
Sperm Duct:
Carries Sperm from testis to urethra
Penis:
Releases sperm and passes into the vagina
Chapter 45: Reproduction,
Growth And Development
Testis:
Produces sperm and testosterone.
Scrotum:
Holds the testes and keeps them at the right temperature.
Chapter 45: Reproduction,
Growth And Development
Prostrate Gland:
Secretes fluid which help sperm to swim – Semen.
Urethra:
Carries sperm during intercourse and urine during excretion.
Chapter 45: Reproduction,
Growth And Development.
Chapter 45: Reproduction,
Growth And Development
Female Reproductive Parts:
Ovary
Neck of womb
Fallopian tube
Womb
Vagina
Chapter 45: Reproduction,
Growth And Development
Ovary:
Produces eggs and oestrogen
Neck of womb:
Cervixentrance to the womb
Chapter 45: Reproduction,
Growth And Development
Fallopian Tube:
Carries the egg from the ovary to the womb
Womb:
Uterus – hold developing embryo
Chapter 45: Reproduction,
Growth And Development
Vagina:
Holds the penis during intercourse.
It is the birth canal, down which the baby passes.
Chapter 45: Reproduction,
Growth And Development
Puberty:
10 – 15 years
Changes to body
Caused by hormones (body chemicals)
Now physically capable of having a baby.
Chapter 45: Reproduction,
Growth And Development
Changes To Body:
Male:
Voice Deepening
Underarm hair
Facial Hair
Sperm Production
Pubic Hair
Chapter 45: Reproduction,
Growth And Development
Changes To Body:
Female:
Underarm Hair
Breasts Develop
Widening Of Hips
Pubic Hair
Chapter 45: Reproduction,
Growth And Development
Menstrual Cycle:
1 egg released from an ovary once a month –
Ovulation.
Egg travels to the uterus
Chapter 45: Reproduction,
Growth And Development
Menstrual Cycle:
The uterus wall becomes thick and rich in blood vessels.
If unfertilized, the egg passes out via the vagina.
Chapter 45: Reproduction,
Growth And Development
Menstrual Cycle:
Menstruation – The uterus wall is now not needed so it breaks down and is also shed
Chapter 45: Reproduction,
Growth And Development
Menstrual Cycle:
This occurs once a month unless the egg is fertilised.
After 45 – 50 years of age, no more eggs are produced
– Menopause.
Chapter 45: Reproduction,
Growth And Development
Intercourse:
200,000,000 sperm released from a stiff, erect penis into woman's vagina
(near cervix) – copulation.
Chapter 45: Reproduction,
Growth And Development
Fertilisation:
Sperm swim through cervix, up the uterus into the fallopian tubes.
If an egg is present fertilisation may occur.
Chapter 45: Reproduction,
Growth And Development
Even if no egg is present, sperm may live for 2 – 3 days in the woman's body.
Egg may live for 24 hours.
Chapter 45: Reproduction,
Growth And Development
Development Of
Foetus:
Sperm + Egg =
Zygote
Zygote divides many times to form ball of cells.
Chapter 45: Reproduction,
Growth And Development
It travels to the womb.
The ball of cells (embryo) sticks to and sinks into the womb wall (full of blood vessels) – nourishment.
Implantation.
Chapter 45: Reproduction,
Growth And Development
The embryo develops for 40 weeks in the womb.
Chapter 45: Reproduction,
Growth And Development
Chapter 45: Reproduction,
Growth And Development
Limiting and spacing the number of children a couple have.
Chapter 45: Reproduction,
Growth And Development
How?
By using contraception:
Natural Methods – avoid intercourse around ovulation.
Chapter 45: Reproduction,
Growth And Development
Artificial Methods
The pill – prevents ovulation
Condoms – Prevent sperm from reaching the egg