Transcript Reproduction MASTER SG

Cells and
Reproduction
Lesson Starter
1. Name one type of cell which is specialised to
its job. Can you describe how it is
specialised?
2. Put the following terms in order of
structure• Organism
• Cells
• Organ
• System
• Tissue
Learning Intentions
• To learn about puberty in humans
Success Criteria
1. State what the term puberty means
2.State the changes in boys during
puberty
3.State the changes in girls during
puberty
Humans are only able to reproduce
after their bodies go through changes
and they reach SEXUAL MATURITY.
We call the onset of sexual maturity
PUBERTY.
Working in pairs, write
down the changes boys
and girls go through
during puberty.
http://www.twigonglow.com/films/introduction-to-puberty-1023/
Changes for Boys
Voice deepens
Grow hair on face and chest
Grow pubic hair
Sexual organs get bigger
Start producing sperm
Shoulders broaden
Hormones produced
http://www.twigonglow.com/films/puberty-in-boys-1025/
Changes for Girls
Breasts grow bigger
Egg released once per month by
ovaries
Grow pubic hair
Sexual organs get bigger
Menstruation begins
Hormones produced
http://www.twigonglow.com/films/puberty-in-girls-1024/
Puberty
Before humans can ________ they must reach
sexual maturity. The process where a human’s
body changes so it is able to reproduce sexually is
called ________.
Both boys and girls grow _____ hair during
puberty.
Their sexual organs get bigger and ________
begin to be produced.
Boys begin to produce sperm and girls begin
___________.
pubic
hormones reproduce
menstruation puberty
Puberty
reproduce they must reach
Before humans can ________
sexual maturity. The process where a human’s
body changes so it is able to reproduce sexually is
puberty
called ________.
pubic hair during
Both boys and girls grow _____
puberty.
hormones
Their sexual organs get bigger and ________
begin to be produced.
Boys begin to produce sperm and girls begin
menstruation
___________.
pubic
hormones reproduce
menstruation puberty
Lesson Starter
At the back of your jotter write a
paragraph on your model cell. Include
the following point:
1. What type of cell you choose to
make and why
2. What material you used to make the
cell
3. If the materials worked well or if
you had to change anything
Starter Puberty
1.
What is puberty?
2.
Who reaches puberty first, boys or
girls?
3.
Give two changes only boys go through
during puberty.
4.
Give two changes only girls go through
during puberty.
5.
Give two changes boys and girls go
through during puberty.
Exercise 5: Puberty
1. What is puberty?
When humans go through changes to reach sexual maturity.
2. Who reaches puberty first, boys or girls?
Girls.
3. Give two changes only boys go through during puberty.
Grow facial hair, shoulders broaden, begin producing sperm.
4. Give two changes only girls go through during puberty.
Breasts get larger, menstruation begins, eggs released from
ovaries once per month.
5. Give two changes boys and girls go through during puberty.
Grow pubic hair, hormones produced, sexual organs get bigger.
Lesson Starter: Label the Diagram
Female Reproductive System
Oviduct/
Fallopian
tube
Uterus
Ovary
Cervix
Upon sexual maturity one
egg is released from the
ovaries every month.
Vagina
Female Reproductive System
Oviduct/
Fallopian
tube
Uterus
Ovary
Cervix
Upon sexual maturity one
egg is released from the
ovaries every month.
Vagina
The Female Reproductive System
Female reproductive system
Organ
Uterus
Oviduct/ Fallopian tube
Ovary
Vagina
Function
Female reproductive system
Organ
Uterus
Oviduct/ Fallopian tube
Function
A muscular sac where a baby
develops
Tubes which carry the egg from
the ovary to the uterus
Ovary
Produce the eggs and female
hormones
Vagina
A muscular tube that opens to
the outside of the body
Lesson Starter
1. What is the function of the uterus?
2. What is the function of the ovaries?
3. What is the function of the fallopian
tubes?
4. Can you remember where the sperm and
the egg meet (fertilisation)?
Male Reproductive System
Urethra
Gland
Sperm duct
Penis
Testes
Upon sexual maturity sperm
begins to be produced.
Male Reproductive System
Upon sexual maturity sperm
begins to be produced.
Lesson Starter
1. What is the function of the testes?
2. What is the function of the sperm duct?
3. What is the function of the scrotum?
4. Can you describe how a sperm cell is well
suited to its job?
Male Reproductive System
Urethra
Gland
Sperm duct
Penis
Testes
Upon sexual maturity sperm
begins to be produced.
The Male Reproductive System
Male reproductive system
Organ
Function
Sperm Duct
Connects to the urethra and
carries sperm away from the
testes.
Testes
Produce sperm and the male
hormone testosterone.
Penis
Carries urine and sperm out
of the body.
Scrotum
The sac in which the testes
are held.
Exercise 6: Which Labels Are
Correct, Which Are Wrong?
Sperm duct
x
Uterus


Ovary
Vagina

Exercise 7: Which Labels Are
Correct, Which Are Wrong?
Urethra

Gland

Oviduct x
Ovary x
Uterus x
Testes

Cervix
x
Lesson Starter
1.Draw and label the
parts of a sperm cell
2.Draw and label the
parts of an egg cell
Sex cells - Sperm
In males the sex cells are called sperm.
Sperm are produced in sex organs called testes.
Nucleus containing
chromosomes
Tail
Middle piece
http://www.twigonglow.com/films/sperm-929/
Cell membrane
Head
Sex cells - Eggs
In females the sex cells are called eggs.
Eggs are produced in sex organs called ovaries.
Nucleus
containing
chromosomes
cytoplasm
membrane
jelly coat
An egg is so big that this is how
big a sperm looks next to it.
http://www.twigonglow.com/films/egg-930/
Sperm or Egg?
Fertilisation:
Fusion of
a male &
female
sex cell
(gamete)
http://www.twigonglow.com/films/fertilisation-931/
The nucleus of the sperm cell (male
gamete) fuses with the nucleus of
the egg cell (female gamete)
Lesson Starter
1.What does the term
fertilisation mean?
2.Draw what you think this
process would look like?
3.What happens after
fertilisation takes place?
Fertilisation in animals
Once fertilisation
has taken place, the
new cell (which is
called a zygote)
starts to divide,
multiply and grow in
size, eventually
producing a new
baby.
Where does
the
fertilisation
take place?
Internal
fertilisation
Menstruation
Once every 28 DAYS an EGG is released from the
ovaries.
It travels down the OVIDUCT towards the UTERUS.
Every month the walls of the uterus thicken up in
preparation in case the egg is FERTILISED.
If the egg is UNFERTILISED the walls of the uterus
break up and pass from the body through the VAGINA
along with the unfertilised egg. This is called the PERIOD
and can last 3-4 DAYS.
If the egg is fertilised then it EMBEDS itself in the
uterus wall and will begin to develop into a new individual.
Menstruation
Once every
ovaries.
It travels down the
an
is released from the
towards the
.
Every month the walls of the uterus thicken up in
preparation in case the egg is
.
If the egg is
the walls of the uterus break
up and pass from the body through the
along
with the unfertilised egg. This is called the
and
can last
.
If the egg is fertilised then it
itself in the
uterus wall and will begin to develop into a new individual.
Lesson Starter
1. How often is an ovum released from the ovaries?
Every 28 days.
2. How long does a period last?
3-4 days.
3. What connects the ovaries to the uterus?
The oviduct.
4. What happens to the uterus in preparation for a fertilised
ovum?
The walls become thicker.
5. How does the unfertilised ovum and the broken-down walls of
the uterus leave the body?
Through the vagina.
A Womb with a View
• In the beginning
sperm joins with
ovum (egg) to form
one cell - smaller
than a grain of salt.
• This union brings together the 23
chromosomes from the father with the 23
chromosomes from the mother to make a
single new life with 46 chromosomes - the
genetic blue print for the development of
every detail this new person will ever have.
• For the next few days
the fertilized egg
travels down the
fallopian tube into the
uterus.
• At the end of the first
week it implants itself
into the lining of the
uterine wall and draws
nourishment from its
mother.
• From Days 1014 the developing
embryo signals
its presence
through placental
chemicals and
hormones to the
mother’s body
telling it to cease
menstruation.
• By only Day 20
foundations of the
brain, spinal cord
and nervous
system are already
established.
• By Day 21 the heart begins to beat.
• By the 4th week, the backbone and
muscles are forming. Arms, legs, eyes,
and ears have begun to show.
• Now one month old, the embryo is 10,000
times larger than the original fertilized
egg and is developing rapidly.
• At Week 5 five fingers
can be discerned in the
hand. The eyes darken as
pigment is produced.
• Brain waves can be
detected and recorded.
• At Week 6 the liver is now taking over
production of blood cells, the brain begins to
control muscle movements and organs.
• Week 7 - The
embryo begins to
move
spontaneously. The
jaw forms,
including teeth
buds in the gums.
• Soon the eyelids
will seal to protect
the embryo’s
developing lightsensitive eyes, and
will reopen at about
the seventh month.
• By the 8th
Week the nowcalled fetus is
a little more
than an inch
long. The fetus
has now
everything
found in a
fully
developed
adult.
• The heart has been beating for more than a
month, the kidneys are functioning; the
stomach is producing digestive juices.
• And it responds to touch.
• At Week 9 the tiny
one has fingerprints
and will curve its
hand around an
object placed in its
palm.
• By Week 10 the
fetus can squint,
swallow, and wrinkle
its forehead.
At the 11th week, the fetus is now about 2 inches
long. Urination occurs. Muscle movements are
becoming more coordinated.
3m
• Now 3 months old, the unborn sleeps, awakens,
and exercises its muscles. It “breathes”
amniotic fluid to help develop its respiratory
system.
Fine hair is growing on the head.
4m
• At 4 months
the fetus is
8-10 inches
long and
weighs half
a pound.
• The mother
starts to
“show.” The
baby’s ears
are
functional.
• It can hear
its mother.
• The fetus at 5 months is now about 12 inches
long. There is definite movement felt by the
mother. The unborn may jump in reactions to
startling or loud noises.
• At the 6th
month oil and
sweat glands
are now
functioning.
The delicate
skin is
protected
from the
fetal waters
by a special
ointment
called
“vernix.”
Born now and given proper care,
the baby would survive…
• At 24 weeks,
this unborn
child was
operated on
for spina
bifida while
still in the
uterus.
• This is Sarah
Marie Switzer,
the baby who
was operated
on above.
• This is about
the time that a
premature baby
can survive
outside the
womb, given
proper medical
treatment.
• This little boy,
here 7 weeks
after birth, was
born when his
mother was only
25 weeks
pregnant.
• At Month 7 the baby now uses the four senses
of hearing, vision, taste, and touch. The child
can respond to his or her mother’s voice.
• In the 8th
month the
skin begins to
thicken with a
layer of fat
stored
underneath
for insulation
and
nourishment.
Antibodies
increasingly
build up.
• The baby is nearly ready for life outside the
womb.
• Toward the end
of this month
the baby is
ready for birth.
By this time the
infant normally
weighs 6 to 9
pounds, and his
or her heart is
pumping 300
gallons of blood
per day.
Any questions?
Lesson Starter
1. What does the embryo use to signal to the
mother to stop menstruation in days 10-14?
2. In what week does the embryo begin to
move?
3. In what month does the mother start to
‘show’?
4. In month 6 what is ‘vernix’ important for?
5. After how many months is the baby ready
for life outside the womb?
Lesson Starter
1. What is the name of the cord that
attaches the mother to the embryo?
2. What is its role?
3. What is the embryo surrounded in
when inside the uterus?
4. What happens to this before labour?
Pregnancy
• During pregnancy the ball of cells in the womb
lining slowly grows into tissues and organs
Amniotic
fluid
Placenta
http://www.twigonglow
.com/search/alt/?q=pr
egnancy
Embryo
Uterus wall
Umbilical
cord
Placenta
Supplies
nutrients
to baby
and
removes
waste
materials.
Amniotic fluid
Acts as a shock absorber to protect
the baby and placenta before birth.
Amniotic sac
Contains the
amniotic fluid
and protects
the baby.
Umbilical
cord
Connection
tube from
placenta to
baby for
exchange of
materials.
Part
Placenta
Amniotic sac
Amniotic Fluid
Umbilical Cord
Function
Supplies nutrients to
baby and removes waste
material
Contains the amniotic
fluid and protects the
baby
Acts as a shock
absorber to protect the
baby and placenta
before birth
Connection tube from
placenta to baby for
exchange of materials
Stage 1:
contractions begin
The baby turns
around its head
facing the vagina.
The uterus wall
begins powerful
contractions and the
amniotic sac bursts
(commonly referred
to as the waters
breaking).
Stage 2:
uterus opening expands
The vagina dilates
allowing the baby’s head
through. If the baby
has not turned around
and the head is not at
the opening of the
vagina it is known as a
breech birth.
Stage 3:
head appears
Once the baby is
born the umbilical
cord is cut and
further
contractions allow
the remains of the
placenta and
umbilical cord to
exit the vagina.
Lesson Starter
1. What is the function of the placenta?
2. What is the function of the umbilical
cord?
3. What is the function of the amniotic
sac?
4. What is the function of the amniotic
fluid?
5. What must happen before the baby is
about to be born?
What is your
DNA??
http://www.twigonglow.com/fil
ms/what-is-dna-1049/
Learning Intentions
To learn about the role of DNA
Success Criteria
1. Where is DNA found?
2. What structure is DNA located on?
3. How many chromosomes does a human have?
4. What chromosomes determine if we are to
develop into a boy or a girl?
Chromosomes
• The nucleus of a cell
contains the instructions for
that organism
• These instructions are
carried by chromosomes
• Chromosomes are thin
thread-like structures
• Every normal cell in a human
body has 46 chromosomes
Chromosomes
• Chromosomes are found in
the nucleus of cells.
• Every normal cell in a human
body has 46 chromosomes
Human chromosomes
• The 46 chromosomes
are actually 23 pairs
• 1 of each pair has
come from the
mother and the
other has come from
the father
Chromosomes
• Sperm cells and egg cells produced
contain only 23 chromosomes
• When a sperm and an egg fuse, the newly
fertilised egg has a complete set of
instructions to develop into a baby ( 23 +
23 = 46)
Number of
Chromosomes 23
Fertilisation
23
Division
46
46
46
What makes us male or female?
• Our 46 chromosomes are arranged as 23 pairs.
• Pair number 23 are our sex chromosomes and
determine if we are male or female.
What are little girls made of?
•XX
What are little boys made of?
•XY
What is the sex of the following
individuals?
male
female
Genes
• Chromosomes are
chains of individual
pieces of
information called
genes
• A gene is a section
of chromosome
which contains a
separate piece of
genetic information
Fertilisation
Sperm
egg
Zygote
2 cells
Zygote
8 cells
4 cells
We’re from our
dad!!
We’re from our
mum!!
I contain my dads
genes
I contain my mums
genes
Brown wavy hair, a
button nose, brown
eyes and
Brown straight
hair, a little pointy
nose, hazel eyes
and pale skin
Sallow skin
And lots more that
you can’t see!!
And lots more that
you can’t see!!
A gene for a characteristic is at
the same place on a chromosome.
Blue eyes
Brown skin
Dad
Brown eyes
Mum
Pale skin
Species
Geranium
Pea
Barley
Turnip
Tomato
Fruit fly
Toad
Human
Chimpanzee
Cow
Chromosome
complement
10
14
14
20
24
8
36
46
48
60
Lesson Starter
1. What is a gene?
2. Where do you inherit your genes
from?
3. If my dad gave me a dominant gene for
long eyelashes and my mum gave me a
recessive gene for short eyelashes,
what length would my eyelashes be?
Risk factors to the embryo
Task
Discuss in pairs what factors you
think might be harmful to an
unborn baby.
Risk factors to the embryo
Factors that can be controlled
by the mother:
Smoking
Alcohol
Drugs
All will be present in the mothers
blood and passed from the mother
to the baby through the placenta.
They will cause difficulties in the
babies growth and general health.
Risk factors to the embryo
Genetic factors:
UV light
X – Rays
Age of mother
All can alter the information
that is passed from the
mother and father to the
baby.
1. State a relationship between the age
of a mother and the change of having
a Down’s Syndrome baby.
Down’s syndrome
Down's syndrome is one of the most common genetic
causes of learning disability. Around 750 babies are
born with the condition each year in the UK.
People with Down's syndrome share a number of physical
characteristics. Not everyone will have all of them, but
they may include:
•reduced muscle tone which results in floppiness
•a small nose and flat nasal bridge
•a small mouth
•eyes that slant upwards and outwards
•a big space between the first and second toe
•broad hands with short fingers
•their palm may have only one crease across it
•a below average weight and length at birth
http://www.nhs.uk/conditions/downssyndrome/pages/introduction.aspx
Detecting Genetic Disorders
Amniocentesis
Doctors can take a sample of the
amniotic fluid using a needle. The
amniotic fluid contains the same
cells as the baby, therefore they
can be studied for genetic disorders
e.g. downs syndrome.
http://www.youtube.com/watch?v=bZcGpjyO
Xt0