chapter 39: reproduction, growth and development by mr. a. rogan

Chapter 39: Reproduction, Growth And Development

By

Mr. A. Rogan


Introduction:Male and female

reproductive organs produce Sex cells (Gametes).


Female sex cell called the ovum or the egg.

Produced in the ovaryOvum – 0.1 mm long


Male sex cells are Sperm.Sperm are produced in

the testisSperm – 0.01 mm long


Zygote – When an egg and a sperm fuse they form a zygote.

Zygotes develop into a new individual.


Fertilisation:Fertilisation is the fusion

(joining together) of an egg cell with a sperm cell.

Chapter 45: Reproduction, Growth And Development Male Reproductive

Parts: Sperm Duct Penis Testis Scrotum Prostrate Gland Urethra


Sperm Duct:Carries Sperm from testis to

urethraPenis:Releases sperm and passes

into the vagina


Testis:Produces sperm and

testosterone.Scrotum:Holds the testes and keeps

them at the right temperature.

Chapter 45: Reproduction, Growth And DevelopmentProstrate 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 DevelopmentFemale Reproductive Parts:OvaryNeck of wombFallopian tubeWombVagina


Ovary:Produces eggs and

oestrogenNeck of womb:Cervix- entrance to the

womb


Fallopian Tube:Carries the egg from the

ovary to the wombWomb:Uterus – hold developing

embryo


Vagina:Holds the penis during

intercourse.It is the birth canal, down

which the baby passes.

Chapter 45: Reproduction, Growth And DevelopmentPuberty:10 – 15 yearsChanges to bodyCaused by hormones (body

chemicals)Now physically capable of having

a baby.

Chapter 45: Reproduction, Growth And DevelopmentChanges To Body:Male:Voice DeepeningUnderarm hairFacial HairSperm ProductionPubic Hair


Changes To Body:Female:Underarm HairBreasts DevelopWidening Of HipsPubic Hair


Menstrual Cycle:1 egg released from an

ovary once a month – Ovulation.

Egg travels to the uterus


Menstrual Cycle:The uterus wall becomes

thick and rich in blood vessels.

If unfertilized, the egg passes out via the vagina.


Menstrual Cycle:Menstruation – The uterus

wall is now not needed so it breaks down and is also shed


Menstrual Cycle:This occurs once a month

unless the egg is fertilised.After 45 – 50 years of age,

no more eggs are produced – Menopause.


Intercourse:200,000,000 sperm

released from a stiff, erect penis into woman's vagina (near cervix) – copulation.


Fertilisation:Sperm swim through cervix,

up the uterus into the fallopian tubes.

If an egg is present fertilisation may occur.


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 DevelopmentDevelopment Of

Foetus:Sperm + Egg =

ZygoteZygote divides many

times to form ball of cells.


It travels to the womb.The ball of cells (embryo)

sticks to and sinks into the womb wall (full of blood vessels) – nourishment.

Implantation.


The embryo develops for 40 weeks in the womb.


Family Planning:Limiting and spacing the number of children a couple have.


How?By using contraception:Natural Methods – avoid

intercourse around ovulation.


Artificial Methods The pill – prevents

ovulationCondoms – Prevent sperm

from reaching the egg

chapter 39: reproduction, growth and development by mr. a. rogan

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