ScienceRevisionforYear8
8B3
Reproduction
In this document you will find:
a) a big ideas for the topic summary sheet
b) a list of key words
c) a ladder setting out the level standards
7B
Summary Sheets
bladder
oviduct
ovary
uterus
Reproduction
Reproduction produces new living things (offspring). Two
parents (one male and one female) are needed for sexual
reproduction. The offspring have features from each parent.
7
B
cervix
vagina
glands
penis
sperm duct
urethra
testis
foreskin
scrotum
Female – ovaries are where the female
sex cells (egg cells) are produced.
The human reproductive systems
Humans have reproductive organs so that they can reproduce.
The ovaries and testes produce sex cells.
oviduct
ovary
uterus
cervix
vagina
Puberty and adolescence
Male
sex ce
bladder
glands
penis
sperm duct
urethra
testis
foreskin
scrotum
Female – ovaries are where the female
sex cells (egg cells) are produced.
Male – testes are where the male
sex cells (sperm cells) are produced.
Sex hormones cause big physical changes to occur during puberty.
Changes in boys
Changes in girls
• hair grows under arms, on face and on chest
• hair grows under arms
• pubic hair grows
• pubic hair grows
• shoulders get wider
• hips get wider
• body smell increases
• body smell increases
• testes start to make sperm cells
• ovaries start to release egg cells
• testes and penis get bigger
• breasts develop
• voice deepens (‘breaks’)
Adolescence is the time when puberty is occurring and emotional changes happen.
It starts between the ages of 10 and 15 and ends at about 18. The changes start sooner
in girls. After puberty, men produce sperm cells for the rest of their lives. Women stop
releasing egg cells at the age of 45–55. This is called the menopause.
The menstrual cycle
The menstrual cycle starts with menstruation (the loss of the uterus lining and some
blood through the vagina). It takes 28–32 days for each cycle. About 14 days after
menstruation starts, an egg cell is released from an ovary. This is called ovulation. If the
egg cell is not fertilised, the uterus lining starts to break down and the cycle starts again.
Sex
The sperm cells enter the vagina during sexual intercourse. Semen (sperm cells mixed
with special liquids from the glands) is forced out of the penis and into the top of the
vagina. This is called ejaculation. The semen is moved into the top of the uterus and the
sperm cells can swim down the oviducts.
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Summary Sheets (continued)
Sperm cells and egg cells
are adapted to their functions.
A sperm cell is much smaller
than an egg cell.
The tip of the head contains
chemicals which attack
the coat of the egg, helping
the sperm to burrow inside.
The nucleus contains half the
instructions needed to make
a new human.
Very little cytoplasm so that
the cell can have a thin,
streamlined shape.
The tail helps it to swim well.
A sperm cell.
Pregnancy
The cytoplasm contains a
store of food to provide
energy for the fertilised
egg cell.
The nucleus contains half
the instructions to make a
new human
A jelly coat makes sure that
only one sperm can enter.
7
B
An egg cell.
If the egg cell meets a sperm cell in an oviduct, fertilisation can occur (the nuclei from
the two cells fuse). The fertilised egg cell divides to form a ball of cells (an embryo). The
embryo travels to the uterus where it sinks into the soft lining (implantation). The woman
is now pregnant. Once it has developed all its organs (after about 10 weeks) it is called
a foetus. It takes about 40 weeks (9 months) for a fertilised egg cell to grow into a baby
ready to be born. This time is called the gestation period.
The fertilised egg cells of many animals grow and develop outside their parents. This is
called external development. Frogs use external development. Humans use internal
development and produce fewer offspring than animals using external development
because the growing embryos are protected inside the mother.
While inside the uterus, the foetus is
supplied with oxygen and food by the
placenta. The placenta also gets rid of
waste (especially carbon dioxide) from
the foetus. The cord (or umbilical cord)
connects the foetus to the placenta.
placenta
amnion
waste materials
(e.g. carbon dioxide)
amniotic fluid to
protect the foetus
foetus
If a mother smokes, drinks too much
alcohol or takes drugs while pregnant,
she might damage the baby. The baby
might be premature.
food and
oxygen
umbilical cord
mother's blood
Birth
When the baby is ready to be born, the uterus starts contractions and the woman goes into
labour. The muscles of the cervix relax. The baby is pushed out head first through the cervix
and the vagina. After birth, the baby starts to breathe and the cord is cut. The scar left behind
is the navel. After this, the placenta is pushed out of the uterus. This is the afterbirth. The
mother’s breasts contain mammary glands that produce milk to feed the baby. Breast milk
contains antibodies that help destroy microbes that might cause a disease in the baby.
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Word Sheets
7Ba – Endangered animals/Starting out in life
Word
Pronunciation
Meaning
cloning
clO-ning
A way of making new organisms from part of one
organism (males and females are not needed).
conclusion
Saying what you think the results of an investigation show.
egg cell
The female sex cell.
endangered
en-dayn-jerd
When a type of organism is in danger of ceasing to exist.
evidence
Results from experiments that show that an idea is right.
external fertilisation
When fertilisation happens outside the bodies of the
parents.
fertilisation
fert-ill-eyes-ay-shun
Fusing of a male sex cell with a female sex cell.
fertilised egg cell
What is produced when a sperm cell fuses with an egg
cell.
fuse
When two sex cells join together to form a fertilised
egg cell.
internal fertilisation
When fertilisation happens inside the body of a parent.
observations
Careful records of what happens in experiments.
parent
An organism that has had a baby.
scientific method
When scientists think up ideas to explain things and then
test those ideas.
sex cell
A cell used for sexual reproduction.
sexual reproduction
Producing new organisms by the joining of two sex cells.
sperm cell
The male sex cell.
theory
thear-ree
7
B
A scientific idea which can be tested by experiments.
7Bb – Reproductive organs
Word
Pronunciation
adapted
Meaning
When something has special features that allow it to carry
out its function.
cervix
sir-vicks
Ring of muscle at the bottom of the uterus in females.
cilia
sil-lee-ah
Small hairs on the surface of some cells.
circumcision
sir-cum-siz-shun
Removal of the foreskin.
foreskin
A covering of skin protecting the head of the penis.
function
Something’s job.
glands
The glands in the male reproductive system add a special
liquid to the sperm cells to make semen.
menopause
men-O-paws
When the ovaries in women stop releasing eggs.
nucleus
new-clee-us
Controls what a cell does
ovary
O-very
Female reproductive organ. Produces egg cells.
oviduct
Carries egg cells from the ovaries to the uterus in women.
Fertilisation happens here.
reproductive organs
Organs used in sexual reproduction.
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Word Sheets (continued)
7Bb – Reproductive organs (continued)
Word
Pronunciation
reproductive system
7
B
Meaning
All the reproductive organs.
scrotum
scrow-tum
Bag of skin containing the testes in males.
semen
see-men
Mixture of sperm and special fluids released by men
during ejaculation.
sperm duct
Tube that carries sperm from the testes to the urethra.
testis
Male reproductive organ. Produces sperm cells. Plural =
testes.
urethra
you-ree-thra
A tube carrying semen or urine running down the centre
of the penis in males. A tube carrying urine in females.
uterus
you-ter-ous
Organ in females in which a baby develops.
vagina
vaj-eye-na
Tube in females. The penis is placed here during sexual
intercourse.
Word
Pronunciation
Meaning
ejaculation
edge-ack-you-layshun
When semen is pumped out of a man’s penis.
embryo
em-bree-O
Tiny new human life which grows by cell division from a
fertilised egg cell.
7Bc – Sex
erection
implantation
When the penis becomes stiff.
im-plant-ay-shun
pregnant
When an embryo sinks into the soft lining of the uterus.
When a woman has an embryo growing inside her uterus.
7Bc – Focus on: Fertility treatment
Word
Pronunciation
IVF
sex hormone
Meaning
A procedure in which fertilisation happens outside the
woman’s body. The embryo develops and is then placed
inside her.
hor-moan
Natural chemical that causes egg cells to be released from
ovaries. Sex hormones have many other jobs in both males
and females.
sperm count
The number of sperm cells in a certain volume of semen.
This is normally 20 million sperm per cm3.
test-tube baby
A baby born using IVF.
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Word Sheets (continued)
7Bd – Periods/Being pregnant/A healthy foetus
Word
Pronunciation
Meaning
amnion
am-nee-on
Bag containing amniotic fluid.
amniotic fluid
am-nee-ot-tick
Liquid surrounding the growing embryo and protecting it.
ante-natal class
Many pregnant woman attend these classes to find
out more about what happens during pregnancy and
childbirth. They learn ways to cope with any problems.
cord
Carries food, oxygen and waste between the placenta and
the growing foetus. Also called ‘umbilical cord’.
foetus
fee-tus
mature
After an embryo has grown all its organs it is called a
foetus. This is usually after about 10 weeks.
Another word for develop.
menstrual cycle
men-strew-al
Series of events lasting about a month, happening in the
female reproductive system. The cycle causes ovulation
and the lining of the uterus is replaced.
menstruation
men-strew-ay-shun
When the lining of the uterus and a little blood pass out of
the vagina as part of the menstrual cycle.
ovulation
ov-you-lay-shun
Releasing of an egg cell from an ovary in women.
placenta
plas-en-ta
Attached to the uterus wall, this takes oxygen and food
out of the mother’s blood and puts waste materials into
the mother’s blood.
premature
sex hormones
A premature baby is one that is small and born early.
hor-moans
ultrasound scan
umbilical cord
7
B
Natural chemicals released in our bodies that control the
menstrual cycle and puberty.
An ultrasound scanner uses sound to create a picture of
what is inside someone’s body.
um-bill-ick-al
See ‘cord’.
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Word Sheets (continued)
7Be – Giving birth/Growing up/Lifecycles
7
B
Word
Pronunciation
Meaning
acne
ack-nee
Spots on the skin.
adolescence
add-ol-less-sense
Time when physical and emotional changes occur in
teenagers.
afterbirth
When the placenta is pushed out through the vagina after
the baby has been born.
antibodies
Substances produced by white blood cells that help to
fight microbes which might cause diseases.
contractions
con-track-shuns
external development
gestation period
The uterus muscles squeezing.
When offspring develop outside a mother.
jess-tay-shun
The length of time from fertilisation to birth.
internal development
When offspring develop inside a mother.
labour
Time when the baby is about to be born.
lifecycle
The series of changes in an organism as it goes through
life.
mammary glands
Glands contained in the breasts of women which produce
milk after childbirth.
navel
nave-ell
offspring
puberty
Scar left by the cord. Often called the ‘belly button’.
The young of an animal.
pew-bert-ty
Time when big physical changes happen in the body of a
teenager.
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Level Ladder
Name
Class
My Target Level is:
7
B
Date
My final level is:
Tick the boxes that apply. Or use traffic lights to show how confident you are (red = ‘I don’t know
this’; orange = ‘I’m not very confident about this’; green = ‘I’m confident I know this’).
Level
At the end of the Unit:
I can do this This needs
more work
Working towards Level 4
State that living things reproduce.
Level 4
Recognise how evidence has changed the ideas we
have about how animals reproduce.
Present data in tables and bar charts.
Describe the main stages of the human life cycle.
Name and identify the main reproductive organs in
humans.
Level 5
Explain the basics of the scientific method.
Find information about reproduction from selected
secondary sources.
Recognise that scientific questions can be answered
using a range of methods.
Draw and interpret data from simple line graphs and
bar charts.
Explain what happens in fertilisation.
Recognise that animals have different lengths of
pregnancy and look after their young to different
degrees.
Recognise the changes that occur during puberty.
Explain the role of the placenta in pregnancy.
Explain the functions of the main reproductive organs
in humans.
Describe what happens in the menstrual cycle.
Level 6
Describe one way in which our understanding of
animal reproduction has changed due to scientific
observations.
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Level Ladder (continued)
Name
Level
Class
At the end of the Unit:
Date
I can do this This needs
more work
Describe ways in which modern science can care for
pregnant women and animals, and their offspring.
Recognise the need for a large sample size in
investigations.
Describe egg and sperm cells and some of their
adaptations.
Explain why a pregnant woman must avoid some
substances.
Describe what happens during birth.
7
B
Describe some of the ways in which a young animal is
cared for.
Level 7
Recognise the reasons behind using fertility treatment.
Identify the many variables that are hard to control in
a survey.
Recognise how knowledge of the results of having sex
is important in making lifestyle choices.
Explain the adaptations of sperm and egg cells.
Explain how sex cells contain the information required
for new life.
Level 8
Explain how reproduction was thought to happen
before sex cells were discovered.
Recognise some of the benefits and drawbacks of
cloning.
Describe the role of chromosomes.
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