B1 you and your genes worksheets

B1 You and your genes

Activity AB1.1.1 Inheritance traffic lights

Say whether you think each statement is:

T true F false ? not sure

1 Sexual reproduction needs a male and a female.

2 Only animals use sexual reproduction.

3 Characteristics are passed on from parents to offspring in
sexual reproduction.

4 In humans the male sex cells are called sperm. The female
sex cells are called ova (or egg cells).

5 In some people there is a third, extra type of sex cell that
produces identical twins.

6 In human reproduction the sperm cell has a tail so it can
move towards the ovum (egg cell).

7 Fertilisation happens when a male sex cell nucleus and a
female sex cell nucleus join together.

8 The instructions to make a new person are found in a
fertilised egg cell nucleus.

9 These instructions are called genes.

10 All of a person’s characteristics are controlled by their
genes.

11 Your blood group depends on what country you grow up in.

12 If you dye your hair red for more than two years, it will make
you have red-haired children.

© University of York (UYSEG) and This page may be copied solely for use
the Nuffield Foundation B1.1-6 in the purchaser’s school or college


Activity AB1.1.2 Talking genes



Activity AB1.1.3 Variation

To answer
1 How many people in your class have:

dangly earlobes

attached earlobes

2 Sketch the shape of these graphs for people aged 14–16 years old:
a earlobe shape b height

3 Complete these sentences to explain why the graphs are different shapes.

a A person’s earlobe shape is affected by just one .

b So you either have attached or earlobes.

c Your height is affected by genes.

d Height is also affected by your .

e So people are not just either or .

f People’s height much more than earlobe shape.

tall varies many environment gene short dangly



Activity AB1.2.1 Cloning plants sheet 1

Cloning cauliflower
To do
Safety note: Take care when you are cutting
you MUST wear
samples. eye protection
1 Cut out a small piece of cauliflower from the
white part.
2 Cut the cauliflower into three small pieces.

3 Drop the pieces into bleach solution. Leave
them to sterilise for ten minutes.

4 Put the pieces into some sterile water. Use
flamed, cooled forceps to do this.
5 Leave the pieces in the rinsing water for at
least one minute.
6 Rinse the pieces in fresh sterile water two
more times.

7 Put one piece into each test tube of growth
medium.



Activity AB1.2.1 Cloning plants sheet 2

8 Label the tubes with your name and the date.
9 Put aluminium foil over the cotton wool. This will
help keep water in.

10 Look at the tubes after ten days and then after
fourteen days.

To answer
11 Why is it important to rinse the cauliflower in bleach
solution?
12 Why is aluminium foil put over the test tubes?
13 Each new cauliflower plant will have all the parts of
a full plant. Explain how this can happen when it
started with only cells from the white part of the
cauliflower.



Activity AB1.2.2 Twin studies sheet 1

Scientists study twins to help find out which characteristics are
mainly affected by genes, and which are affected by the
environment as well.
Twins who have been separated at birth and brought up in
different homes give us lots of information.
Non-identical twins are normal siblings who share a womb and
are born at the same time.
The table shows you some of the data scientists collected in a
study of twins and non-twins in the US. They looked at the
differences between twins and other pairs of siblings. These
measurements are used to show how similar or different they are.

Identical twins Identical twins Non-identical Non-twin
Characteristic
reared together reared apart twins siblings
Height
difference 1.7 1.8 4.4 4.5
(cm)
Mass
difference 1.9 4.5 4.6 4.7
(kg)

IQ score
5.9 8.2 9.9 9.8
difference

To do
1 Make bar charts to show the data for height difference, mass
difference and IQ score difference (IQ is a way of measuring
intelligence).
2 How can these data help you decide whether a
characteristic is mainly decided by your genes or if the
environment plays a big part?
3 Using this information, which characteristic do you think is
most strongly decided by the genes?
4 Why do identical twins who have been brought up in
different homes give us so much important information?
5 What does the data tell you about the characteristics of non-
identical twins and ordinary siblings?
6 What more would you want to know before you rely on the
results of this study to tell you about the links between genes
and the environment?



Activity AB1.2.2 Twin studies sheet 2

To find out
You can find out more about some twin studies at two website
addresses your teacher will give you.
Find out about at least one of these stories and write a brief
case history of the twins described. Explain how an individual
story like this can be useful to scientists and what would need
to be done to get some scientific data from the study.



Activity AB1.2.2 Twin studies

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Activity AB1.3.1 Inheriting genes sheet 1

Fertilisation
1 Humans have pairs of chromosomes.

2 The bands on chromosomes show different .

3 Chromosomes are in pairs, so come in pairs too.

4 The only cells that don’t have pairs of chromosomes are the

cells.



Activity AB1.3.1 Inheriting genes sheet 2

Why don’t brothers and sisters look the same?
Brothers and sisters may have the same parents, but still not
look the same. Complete the sentences to explain why:
5 Sex cells have only 23 chromosomes. Sperm cells get a

copy of just of the chromosomes

from each pair a man has.

6 Lots of different sets of 23 chromosomes can be made.

No two sex cells get the same of chromosomes.

7



Activity AB1.3.1 Inheriting genes




Activity AB1.4.1 Male or female?

Sex chromosomes carried
Egg cell Fertilised egg
Sperm cell
(ovum) cell

To answer
1 What sex chromosomes do sperm cells carry?

2 What sex chromosomes do egg cells carry?

3 Is it the sperm cell or the ovum that determines the sex of a baby?

4 Henry Vlll blamed several of his wives for failing to give him a
son. Anne Boleyn and Catherine Howard (his second and fifth
wives) were beheaded. He divorced two more of his six wives.
Do you think he was correct in blaming his wives? Explain your answer.



Activity AB1.4.2 Inheriting sex

To answer
1 How many pairs of chromosomes are there in a human body cell?

2 Which pair of chromosomes controls what sex a person is?

3 What pair of sex chromosomes does a woman have?

4 What pair of sex chromosomes does a man have?

5 How many chromosomes does a human egg or sperm cell contain?

6 A couple have three sons. They are having a new baby.

What is the chance that it will be a boy?

Complete the diagram to help you.



Activity AB1.4.3 Caster Semenya’s story

In August 2009, 18-year-old Caster Semenya from South Africa
won the gold medal in the women’s 800m. Her life has never
been the same since.
Caster is very tall and muscular. After she won the race, the
International Association of Athletics Federations (IAAF) said
that she was undergoing gender verification to see if she was,
in fact genetically male.

To find out
You will find a lot of information about this story on the Internet;
your teacher will give you a link to get you started.
• Find out about Caster’s upbringing and her great running
ability.
• See if you can discover why it took so long to decide if
Caster could keep running as a woman.

To present
Write a short a newspaper article on Caster’s story
summarising what you have found out.
You need to explain the difference between males and females
genetically, and how this affects the way their bodies develop.



Activity AB1.4.4 Looking at sets of chromosomes sheet 1

There is a set of chromosomes in every body cell.
The set of chromosomes of a normal human male and normal
human female are shown below.



Activity AB1.4.4 Looking at sets of chromosomes sheet 2

To answer
1 What difference is there between the male and the female
set of chromosomes?
2 The set of chromosomes of a person with Klinefelter’s
syndrome is shown below.

Describe how the Klinefelter’s karyotype is different.
Klinefelter’s syndrome produces a sterile male with little
facial hair, some breast development, and small testes.
3 Read the Textbook Section D Male or female? Explain why
a person with Klinefelter’s syndrome is male, not female,
even though they have two X chromosomes.
4 Half of all miscarriages are due to chromosome
abnormalities. This means that parts of chromosomes are
missing or duplicated. Using your knowledge of how genes
affect development, suggest why chromosome abnormalities
usually cause serious symptoms in an individual.



Activity AB1.5.1 Alleles

Different versions
A pair of chromosomes carry the same gene in the same place. Genes
come in more than one version. A person can have two different
versions of a gene. Or they can have two versions the same.
1 Why do people have two copies of every gene?

2 What do we call different versions of a gene?

3

Like all human beings, John and Carl each have two copies
of the gene that controls the shape of their earlobes.
John’s two copies are very slightly different from each other.
Label the diagram of John’s earlobe genes.

4 Explain why John has unattached earlobes.

5 Explain why Carl has attached earlobes.



Activity AB1.5.2 Modelling fertilisation sheet 1

Prediction:

Number of pairs of beads with …
spot on just one bead spot on both beads spot on neither bead

Total = Total = Total =

To answer
1 How closely do these results match your prediction?

2 Complete these sentences.
In the experiment it was chance which you
picked up each time.
Fertilisation is like that too.
You cannot predict which sperm will fertilise an

cell.



Activity AB1.5.2 Modelling fertilisation sheet 2

Prediction:

Number of pairs of beads with …
two red beads one red, one yellow bead two yellow beads

Total = Total = Total =

To answer
• How many plants were

a tall?

b short?
3 How do the results compare with your predictions?

4 What other factors apart from chance may have affected
which beads you picked?



Activity AB1.5.3 Genetic crosses

Genetic crosses
Remember: a person’s eggs or sperm contain only one
chromosome from each of their pairs.
So they only get one of the two genes a person has for each
characteristic.
• Sometimes a parent has two different versions (alleles) of a gene.
• So, we cannot be sure which version they will pass on to a child.

To do
Complete the Punnett square.



Activity AB1.5.4 Pairing up sheet 1



Activity AB1.5.5 Predicting inheritance sheet 1

1 Pea plants can be tall or short.
Their height is controlled by just one gene.
The gene has two alleles:
tall allele (T) is dominant
short allele (t) is recessive
A tall plant with the alleles TT is bred with a short plant with
alleles tt.
All the new plants are tall.
a Complete the diagram to explain why.




b One of the new plants is bred with another short plant.
What pair of alleles must the short plant have?

Complete the diagram to show what percentage of the
new plants will be tall.

The percentage of tall new plants is %.




2 A couple who both have bent little fingers have three
children.
Two of the children have straight little fingers.
One child has bent little fingers.
Complete the diagram to explain how this happened.
The allele for bent little fingers (B) is dominant.
The allele for straight little fingers (b) is recessive.




3 A couple who both have attached earlobes have a baby son.
The allele for unattached earlobes (E) is dominant.
The allele for attached earlobes (e) is recessive.
The mother’s alleles are EE.
The father’s alleles are Ee.
Complete the diagram to show what alleles their son could
have.




4 PTC is a chemical that many people can taste as being
extremely bitter.
People who taste it have at least one dominant tasting
allele, T.
Some people cannot taste the bitter compound at all.
They have two recessive non-tasting alleles, tt.
Explain how two people who can both taste PTC can have
children who cannot taste the chemical at all. You can use
diagrams to help you.



Activity AB1.6.1 Cystic fibrosis sheet 1

Symptoms of cystic fibrosis
Some cells in the human body make mucus.
This is the thick, slimy liquid that lubricates
surfaces inside the body.
Shane and Laura have cystic fibrosis.
Their mucus-making cells don’t work properly.
They make mucus that is too thick.
It causes problems in the breathing system
by clogging up the lungs.
It also blocks the tube from the pancreas
which normally carries enzymes to the gut.
The thick mucus in their lungs can make
them short of breath.
They are also more likely to get chest
infections.
The lack of enzymes in their guts means
that food isn’t digested properly.
So they are short of nutrients.

Treatment
Cystic fibrosis cannot be cured.
However treatments are getting better and
life expectancy is increasing all the time.
Shane and Laura have to have
physiotherapy several times a day to clear
the mucus out of their lungs.
They need antibiotics every time they get
a chest infection.
They can use an enzyme to thin the mucus.
This makes it easier to get rid of.
They also take digestive enzymes with every meal.
New treatments may offer hope for the future.




To do
1 Underline information that explains how symptoms are
caused.
2 Shade in one colour symptoms and treatments to do with the
lungs.
3 Shade in a different colour symptoms and treatments to do
with digestion.
4 Circle any other information about treatments.



To do
1 Underline information that explains how symptoms are
caused.
2 Shade in one colour symptoms and treatments to do with the
lungs.
3 Shade in a different colour symptoms and treatments to do
with digestion.
4 Circle any other information about treatments.



Activity AB1.6.2 Two inherited conditions sheet 1

Huntington’s disease

Cystic fibrosis




To do
1 Look at the two family tree diagrams.
One family is affected by Huntington’s disease.
The other family is affected by cystic fibrosis.
• Copy and complete the table. You are comparing the
pattern of the two disorders.

Name of disorder Huntington’s disease Cystic fibrosis
Key H = Huntington’s allele F = normal allele
h = normal allele f = cystic fibrosis allele
Do the parents of the
affected people also have yes/no yes/no
the disease?
What are the allele pairs of
HH or
people with the disease?
What are the allele pairs of
Ff or
people without the disease?

2 The allele for Huntington’s disease is dominant.
The rule for dominant alleles is:
‘A dominant allele will always cause an effect.’
The allele for cystic fibrosis is recessive.

Write a ‘rule’ for recessive alleles.




To answer
3 A carrier is someone who has one copy of an allele for a
disorder, but does not have the disorder.
a Decide who is a carrier in each family.

Huntington’s disease:

Cystic fibrosis:

b Then copy and complete these sentences. Use the words
in the box.

one dominant recessive no will carrier

The allele for cystic fibrosis is .

A person with copy of the allele will not
have the disorder.

They are a .

The allele for Huntington’s disease is .

A person with one copy of the allele have
the disease.

So there are carriers of Huntington’s
disease.



Activity AB1.6.2 Two inherited conditions




Activity AB1.7.1 Shall we have the test?

Each of the couples below have a problem. What advice would
you give them based on the science you know? Work in small
groups to plan what you would say to these couples. Use your
Textbook and the two websites that your teacher will give you to
help you.

Kris and Jani are both 40 years old and are expecting their first baby.
‘We’ve waited a long time to have this baby. We think the risks of there being
something wrong are higher because we’re older, but we don’t want to lose the baby.
I might never get pregnant again at my age. So what are the risks of having these
tests?’

Jaz and Jo know that some people in their family have had the genetic disease
thalassemia, which can be very serious. They have just found out they are expecting
a baby.
‘We think we ought to have a test to see if our baby is affected by thalassemia. But
which test is better – CVS or amniocentesis?

Marcus and Sophie have three little girls. Sophie has just discovered she is pregnant
again.
‘We’re desperate to know if the new baby is a little boy. I want one of those CVS
tests to find out as soon as possible. How can we get one?’

Since Fred and Lizzy had their first, healthy baby, Fred’s brother has had a little boy
who has cystic fibrosis. Fred and Lizzie are now expecting their second child.
‘We don’t know what to do. Some friends were told their baby probably had a genetic
problem but they didn’t have an abortion and the baby was fine when it was born.
We’ve already got one healthy child – the risks from the test are probably worse than
the risk of us having a baby with CF. But then you worry…we don’t know what to do.’



Activity AB1.7.2 Ethics

When a person has to make a decision about what is the right
or wrong way to behave in a particular situation, they are
thinking about ethics. Deciding whether to have a termination is
an example of an ethical question. There are often no easy
answers to ethical questions. However, there are ways of
thinking about these questions that can help you make a
decision.

What do you need to know?

Making a decision
For each possible action, think about each of these questions.


6B1 You and your genes

Activity AB1.7.3 Decision making sheet 1

Some couples know they could have a child with cystic fibrosis.
They may have to make some difficult decisions.
This activity helps you explore how people make these
decisions.
Your group will take on the role of a couple or their genetic
counsellor.

What different choices could the couple make?
Make a list.

Number the choices in rank order.
1 is the choice you think they are most likely to make.

Prepare your role-play:
• The couple discuss their options with the counsellor.
• The couple may start with different viewpoints.
• They may change their minds as they talk.

• Present your role-play to another group.

Watch other role-plays:
• Have the role-plays changed your opinion?


B1 You and your genes 7


Discuss these questions in your group.
Ask for any extra information that you need.
What are the benefits of
this decision?
caused by this decision?
What harm may be
information provided by
How reliable is the

any testing?

• Allow ‘nature’ to take its

• Genetic testing of the
course – no testing
• Do not have any
Possible decision

children

fetus




The couple
Laura’s nephew – her brother’s son – has cystic fibrosis. Laura and
Paul are worried about any children they may have. They are
trying to decide what to do:
• not have any children
• try to adopt a child
• have the child without a pre-natal test
• have genetic testing of the fetus
• if the test shows that their child has cystic fibrosis, whether
to have a termination

Genetic counsellor
A good place to start would be to ask Laura and Paul to explain
what they understand about their situation.
Once the couple has started talking, the counsellor has to make
sure that they understand the science of cystic fibrosis properly –
how it is inherited, as well as all the options that are available to
them.
The counsellor also has to draw out the true feelings of the
parents about issues such as caring for a child that may be
severely affected by the disease and about terminating an affected
pregnancy.



Activity AB1.7.3 Decision making

Summary flowchart: possible viewpoints



Activity AB1.8.1 Finding the right medicine

Can we make medicines more effective?
If medicines can be designed to work with our individual genetic
makeup then they should work more efficiently, in lower doses,
with fewer side effects. The new science of pharmacogenomics
involves developing new medicines using information about
drugs (pharmaceutical expertise) along with knowledge of the
human genome and people’s individual genetic makeup.
Some research shows that genetic factors have a big effect on
the efficiency of certain drugs. Pain killers called kappa opioids
work much better in women than in men. Many pain killers have
a bigger effect on pale-skinned red-haired women than anyone
else.

What sort of benefits are pharmacogenomics likely to bring?
Scientists hope to use what they know about the human
genome to make more powerful drugs which target cells with
changes in their proteins or genetic material. They want to
produce medicines which affect pathogens or cancer cells but
do not damage healthy human cells.
In the US, around 100,000 people die each year, and 2 million
people go to hospital, because they react badly to a drug they
are given. If doctors know a patient’s genome they will only
give drugs which are safe for that person.
At the moment, doctors use the age or weight of a person to
decide what dose of a drug they should be given. Genetic
information would let doctors work out just how rapidly each
person deals with a particular medicine. Many people could
have much lower doses of medicines, whilst those who need it
could be given higher doses.

To answer F
1 What is the human genome?
2 What is pharmacogenomics?
3 Give one example of the effect that your genes have on the
way medicines work.
4 Give two ways in which scientists might be able to use
knowledge of your gene sequence to make sure you are
given the best medicine possible.
5 Some people think that pharmacogenomics will cause
problems in the production of drugs for the developing world.
Suggest why people are worried about this.



To answer H
1 What is the human genome?
2 What is pharmacogenomics?
3 Give one example of the effect that your genes have on the
way medicines work
4 How can knowledge of the genome help scientists develop
better medicines against cancer?
5 Personalised medicines should save a lot of money. Explain
two of the ways in which this new way of developing and
using drugs could benefit both individual patients and the
NHS.
6 Some people think that personalised medicines will cause
problems in the production of drugs for the developing world.
Suggest why people are worried about this.
7 Suggest another ethical dilemma which may be raised by
the use of adult genetic testing in finding the best possible
medicine for each individual.



Activity AB1.9.1 Your genes – but who decides?

To do
Work in groups and discuss each of the situations below.
Present your conclusions and reasons to the rest of your class.

1 Chelsea’s older sister had breast cancer when she was only
28. A genetic test shows that Chelsea has a high risk of
getting the disease too. Chelsea is just buying her first flat
and she needs to take out life insurance.
Do you think she should be forced to tell the insurance
company about the results of her test?

2 Hardip has always wanted to be an airline pilot and he has a
place to train with a big international airline.
Hardip’s dad had a heart attack when he was 40 and his
uncle died of a heart attack when he was only 39. Genetic
tests reveal Hardip has two genes which are linked to a high
risk of heart disease. Should Hardip inform the airline before
he starts training?

3 You are taking your partner and young family on a special
holiday to America for the first time. Would you expect the
airline to have checked the pilot of your flight for any genetic
problems such as an increased risk of having a heart attack?

4 Liam’s dad was an alcoholic. His mum smokes very heavily.
One of his sisters is addicted to gambling and has had a lot
of money problems. His other sister is a teacher and his
brother is a car mechanic, and they do not drink, smoke or
gamble.
Liam’s genetic sequence shows that he has inherited some
of the genes which increase the risk of becoming addicted
easily. He has a good career in the local hospital and
doesn’t drink heavily or smoke. He and his girlfriend Kirsty
are getting married and want to start a family. Should Kirsty
be told the results of Liam’s test?



Activity AB1.9.2 Stereotype of the karyotype sheet 1

Some men – about one in 1000 – have an extra Y chromosome
in every cell of the body, so they are XYY. Your set of
chromosomes is called your karyotype, so these men have the
XYY karyotype.
An article by the medical journal The Lancet in 1968 said that
XYY men are more common in prison than you would expect. In
other words, more than one in 1000 male prisoners is XYY.
This led to the idea that the extra Y chromosome makes men
more aggressive and more likely to commit violent crimes.
What is it like to be XYY? Are these ideas about violence fair?
Here is what it’s like from the inside: the story of Edward (Ed)
Friedlander. Read what Ed has to say then answer the
questions.

To read
XYY – Stereotype of the karyotype
Adapted with permission from website by Edward R. Friedlander, MD.
“I’m Ed. I'm a pathologist in Kansas City, and run the largest free personalised
medical information service on the internet.
I am tall, lean, and physically powerful. At age 47, I still take medicine for acne.
I have a temper that I work hard to control. And I've learned to avoid situations
that set me off. I have never physically hurt anyone in anger.
I’m a macho, fun, well-liked man who enjoys being single and lives clean.
There's been some romance, and no real problems here. A few women have even
said I'm good-looking and/or a nice guy.
My muscles are stronger than they are coordinated, so I’ve focused on strength-
endurance sports like gymming and swimming. But I type as fast as most of the
secretaries. And I’m a fair keyboard player.
I've got a pectus chest deformity and a wiring problem with my left eye.
Cognitively, I’m a little ‘different’ and always have been. But it doesn't bug me.
Most males have the 46-XY karyotype, but about 1 guy in 1000 has two Y
chromosomes, and is an XYY. If XYY men are at any greater ‘risk’ of fathering
XYY or XXY sons, the increase is small.
When first discovered, popular science writers speculated that the extra ‘Y’
would make owners act more masculine – ie, more aggressive, irresponsible, and
criminal. Uh-huh. Richard Speck, the killer of eight student nurses, pretended
(falsely) to be an XYY to obtain leniency, thus popularising the ‘XYYs are
criminals’ story.
continued




The famous Nielsen letter in Lancet Sept 7, 1968 claiming that the prevalence of
XYY men in prison was ‘25–60 times as high as the prevalence in the general
population’ remains a shocking example of how to mislead the public using
small-sample statistics – there were only two XYYs identified in the study.
Aliens 3 was set in an offworld ‘penal colony for XYYs’, and folklore continues
to this day.
There’s no question that XYYs average substantially taller, tend to be wiry-built,
and tend to have severe acne. Minor birth defects – like pectus, crooked eye, and
minor out-turning of the elbows, are supposed to be common in XYYs.
It will probably not surprise any adult visitor to this site that the average blood
testosterone (the rocket-fuel that drives male sexual characteristics and
behaviours) averages much higher in some men than in others. XYYs average
higher than XY men. Men in prison average higher than men not in prison. When
you control for the high testosterone levels, the most recent published study (from
1984) showed there is no over-representation of XYY men in prison.
XYYs average only slightly lower intelligence than XYs, and the range is the
same for both groups. If XYYs really exhibit severe behaviour problems, it has
resisted demonstration by the best scientific minds in the field of genetics.
Here’s why – it's something called ‘ascertainment bias’. Kids who are screened
for chromosomal problems tend to have learning and/or behaviour problems. If
they come up with XYY, it's easy to blame the karyotype. What’s more,
somebody doing bad science can get up a series: ‘Look at all the XYYs I’ve
discovered, and most of them have mental problems!’ (See the fallacy?) But to
date, nobody’s shown that XYYs are more common among kids who are
screened for these problems than in the general population. And if XYY was
itself a major problem, you’d think this would have been accomplished long ago.
When I’m certain I won’t lose my own health insurance, I’ll find out for certain
whether I am an XYY. In the meantime:
• I have the phenotype, and...
• I like it, and...
• Most folks who know me like it, too.
I hope you came here wanting straight answers. If your boy has XYY, give
structure, fairness, love, and time with Dad or a good substitute to teach him
how a happy, good man should act. You’d do this for any boy. In the politicised
climate of genetic counselling, you’ll probably get a welter of confusing
information ‘so that you can make your own decision’ about abortion. I’m NOT
your doctor, so I can talk straight.
After reviewing the evidence, I find no reason to think that XYY makes men
crazy, retarded, or criminals.
continued




If you are considering ending the life of your unborn child ‘just because he is an
XYY’, don’t do it.

I have received dozens of E-mails about this page from parents
of XYY boys. Most of them shared that their sons showed no
particular behaviour problems. Several mentioned their sons
having short fuses and being hard to handle when they are
angry, but that’s been all. Others have expressly said there’s
been no particular temper problems. To date, not one of them
regrets bringing their boy into the world.

To answer
1 Ed is probably XYY. What sex chromosomes do most males
have?
2 How many chromosomes do most people have in every
body cell?
3 How many chromosomes does an XYY person have in
every body cell?
4 Your body’s characteristics like hair colour, height, and blood
group are called your phenotype. Give three unusual
features of the phenotype shown by most XYY men.




5 Ed says, ‘I have the phenotype, and I like it, and most folks
who know me like it too.’ He is not yet certain that he is XYY
as he has not had his karyotype checked. He is worried that
no-one would give him health insurance if he was tested as
XYY.
Give two reasons why an insurance company might not give
Ed health insurance.
6 Two boys, Fred and John, are badly behaved in school.
They both eat a lot of junk food. They have their karyotypes
checked. Fred is XY and John is XYY. A doctor concludes
that Fred’s bad behaviour is probably due to the additives in
the junk food but John’s bad behaviour is because he is
XYY.
Explain whether the doctor is correct in deciding the reason
for John’s bad behaviour.
7 If it turns out that XYYs are more common in prison than
expected, does this show that the XYY karyotype makes
men become criminals?
8 Suggest why Ed calls his article ‘XYY – Stereotype of the
karyotype’. What point is he making?



Activity AB1.9.2 Stereotype of the karyotype




Activity AB1.10.1 How are embryos selected?



Activity AB1.10.2 Embryo selection – sheet 1
what should be allowed?

Human Fertilisation and Embryology Authority (HFEA)
Genetics can be used in different ways.
The HFEA decides what should be allowed.
One of the things it controls is embryo selection.
Doctors must apply to the HFEA each time they want to do this.
The HFEA has:
• doctors
• scientists
• people who don’t work in science

Human Fertilisation and Embryology Authority (HFEA)
Genetics can be used in different ways.
The HFEA decides what should be allowed.
One of the things it controls is embryo selection.
Doctors must apply to the HFEA each time they want to do this.
The HFEA has:
• doctors
• scientists
• people who don’t work in science




To do
1 Make sure that everyone in your group understands what
pre-implantation genetic diagnosis is.
To check this, imagine you are explaining it to someone who
doesn’t know. What would you say?
2 Look at your group’s case.
3 Make a group decision for each case. Use your ethics sheet
to help you. How will you make the decision if you disagree?
4 Explain your decision to people who have looked at other
cases.
5 Write a set of rules for the HFEA to use when it is
considering other cases.



Reasons
Should embryo selection be allowed?
(yes/no/not sure)
Case

1

2

3

4




Case 1
A family has three sons.
The parents would like to have a daughter.
They want the chromosomes of their embryos to be checked.
They will only implant female embryos.

Case 2
A couple are both carriers of cystic fibrosis.
They want to have a child, but do not want their child to have cystic
fibrosis.
A genetic test showed that their first child had cystic fibrosis.
They terminated the pregnancy.
They do not want to terminate another pregnancy. They want to
check the genes of their embryos before they are implanted.
They will only implant embryos that do not have cystic fibrosis.




Case 3
A couple’s daughter has a rare disease. It is not inherited.
Their daughter needs a transplant to survive.
But a matching donor cannot be found.
Her parents want to have a child who can be a donor for her.
Their embryos’ genes would not normally be checked.
A new child is no more likely to have this disease than anyone else.
The parents want to check their embryos’ genes to find a match for
their daughter.
They will only implant embryos that could be donors.

Case 4
A couple’s son has a rare disease. It is inherited.
There is a 25% chance that any other children they have will have
the disease.
Their son needs a transplant to survive. But a matching donor
cannot be found.
His parents want to have a child who can be a donor for him.
The embryos’ genes will be checked to make sure they do not have
the disease – the law allows this already.
They also want to check their embryos’ genes to find a match for
their son.
They will only implant embryos that will not have the disease and
could be donors.



Activity AB1.10.2 Embryo selection –




Activity AB1.11.1 Asexual reproduction

Bacteria are only one cell. They are unicellular. Some plants
and animals are also unicellular. Some are made of small
groups of cells that are all alike. These organisms reproduce
asexually. Their cells grow and split over and over again.

Some larger plants and animals can also reproduce asexually.
Only one parent is involved. Small groups of body cells divide to
make new offspring.
Before a cell divides for asexual reproduction, its chromosomes
are copied. The new cells each get a set of these
chromosomes. So their genes are exactly the same as the set
in the original cell.
Genetically identical organisms are called clones. The
characteristics of clones are very similar to each other.

To answer
1 A multicellular organism has many cells. What do we call an
organism with just one cell?

2 Underline a word in the text that means reproduction
without sex.
3 Draw a ring round a word for organisms that have
identical genes.
4 The final sentence in the text says that clones look very
similar. Why don’t clones always look identical?



Activity AB1.11.2 Stem cells sheet 1




To answer
1 Match each term to the correct definition. One has been
done for you.

Opinion Suggesting possibilities that might happen. Goes beyond fact.
Speculation Something that people accept as having been proved true.
Evidence Someone’s viewpoint. May not be based on evidence.
Explanation Information that is linked to the issue.
Fact An idea to explain some evidence.

2 Read this passage. Then answer the questions.

Stem cells a cure for Type 1 diabetes?
Type 1 diabetes is a condition where the body’s immune system destroys the cells that make
insulin in the pancreas. People with this disease cannot regulate their blood sugar. This causes
complications like blindness, kidney failure, heart disease, stroke, and amputations. People
with type 1 diabetes have to take insulin for the rest of their lives to keep their insulin levels to
as near normal as possible.
In a US/ Brazilian experiment, diabetic patients were given transplants of stem cells from their
own bone marrow. This stem cell treatment has helped patients with type 1 diabetes to
produce their own insulin.
Out of 23 patients, 20 no longer required insulin injections. One patient remained insulin-free
for up to 4 years. The treatment was not effective on people who had had diabetes for longer
than three months. This is because the cells that make insulin are all destroyed after that time.
This treatment could relieve diabetics from injecting synthetic insulin. However, this
treatment is unlikely to be a cure.

3 In the account above:
a Underline in red a description of the stem cell treatment.
b Underline in two different colours:
• the evidence that some diabetics were able to
produce their own insulin
• the speculation that stem cell treatment could mean
that diabetics would not need to inject insulin.




4 In the third paragraph:
a Underline in a different colour an explanation.
b In the last paragraph underline in red an opinion.
5 Is there any evidence that this opinion could be biased?

6 Consider the ethical issues If the stem cells were taken from
embryos rather than from the person themselves.



Activity AB1.11.3 Having an argument sheet 1

What is an argument?
An ‘argument’ might mean a disagreement.
An ‘argument’ can also mean a ‘point of view defended by
reason’.

Making a good argument
In a discussion, you need to put forward your point of view
clearly. You need to:
• Sum up your argument in one or two sentences.
• Explain the reasoning behind your argument.
• Set out the key points and any evidence to support them.
• Say why you think the evidence is reliable.
Arguments can be extreme
• Consider other views, describing evidence for and against. views, or more balanced.
• Explain why you think that the evidence for your point of
view is stronger.

Summarising a written argument
Summarising different points of view makes it easier for you to
explain why you think your argument is stronger.
Paragraphs in text are used to split the argument into sections.
• Look for key points – these are the main points of the
argument.
• Look for clear reasoning.
• Look for facts that back up the argument.
• Look for case studies and examples. These are often used
to persuade people to agree with an argument.
• Look at the conclusion. It usually summarises the writer’s
point of view.
To summarise an argument in a newspaper, use highlighter
pens to mark important parts. This is quicker than writing notes.



Activity AB1.11.3 Having an argument sheet 2

My argument:

Key points: Evidence and examples to back up my
key points, or argue against them:

Other points of view: Evidence and examples that could be
used to back up other points of view, or
argue against them:

Why I think my argument is stronger:

Conclusion:



Activity AB1.11.4 Planning your presentation sheet 1

Who is it for?
• Think carefully about who will be in your audience.
• Choose information that will be interesting to them.

What is the purpose of your presentation?
• What do you want people to learn from your presentation?
• Do you want to explain the causes?
• Do you want to tell them about treatments and current
research?
• Only include information that helps you do this.
• Too much information can be boring.

How much information should you include?
• Choose five or six main themes.
• Each main theme should have one slide of text
• Don’t have more than three or four bullet points on a slide.
• Don’t put everything you want to say on the slide.
• When you give your presentation you can include extra facts
to support each point.
• The bullet points help you to remember what you want to
say.
• Choose images that help you to explain your points.
• You will be given some partly written slides to help you get
started.
• Change these to suit your presentation.
• You can change the order of the slides, the information in
them, and the design.
• You could design your own presentation without using these
slides.




The purpose of my presentation is:

My presentation is aimed at:

My main themes are:
1
2
3
4
5
6

The bullet points for each main theme are:
1
2
3
4
5
6

The images I am going to use for each main theme are:

1
2
3
4
5
6




Designing your presentation
1 Researching
Choose the information and picture slides that you want to use.
Find other information from different sources. Don’t copy lots of
information just to fill up space. Your audience might not find
that interesting! Use the information to explain your points.

2 Deleting slides you do not want
Look at the slides in the presentation template.
• Click View from the top menu bar.
• Click Slide Sorter.
• Click on any slide you do not want. Click Edit from the top
menu bar and click Delete Slide.

3 Using pictures from the Internet
You may be able to use pictures from the Internet in your presentation.
• Click on the picture with your right mouse button and click Copy.
• Go back to your PowerPoint slide.
• Click your right mouse button and click Paste.
You can drag the picture around the slide to put it where you want.
• Click Format Picture with your right mouse button to change
the size of your picture.
• Change the height to what you want.
• Click in the Width box. It will automatically work out what the
correct width should be. Click OK.

4 Changing the order of your slides
• Click View from the top menu bar.
• Click Slide Sorter.
• Click on the slide you want to move. Drag it in between the
slides where you want it to be.
5 Inserting new slides
You can add new slides to type information onto. Choose the
slide that you want your new one to come after.
• Click on this slide.
• Click on Insert from the top menu bar.
• Click New Slide.



You can choose a particular layout. The layouts give you
spaces to put text or pictures in.
You can always change the size of the text and picture For example:
boxes by clicking in the box and moving the edges.
• Click on the text layout you want and click OK.
Your new slide will be inserted into your presentation.
If you choose a blank slide you can put text wherever
you like.
• Click the text symbol (‘A’) on the bottom menu bar.
• Click on your slide where you want the text to go.
A text box will appear that you can type in.

6 Copying text from the Internet
Highlight the text that you want. Do this by holding down
your mouse button and moving over the text. Click your
right mouse button.
• Click Copy.
• Go back to your PowerPoint slide.
• Click your right mouse button.
• Click Paste.
You will probably have to change the font, size, and colour of
the text.

7 Getting very fancy
You can give your slides different designs, colours, and layouts
if you like. Click Format from the top menu bar. Try
experimenting with Slide Colour Scheme, Background, and
Apply Design Template. To get rid of a change click Edit from
the top menu bar and click Undo. Sound effects can also be
added to PowerPoint presentations.



Activity AB1.12.1 Adult stem cells sheet 1

To do
Use the points made above and Activity AB1.11.2 to produce a
table comparing the possible use of embryonic stem cells and
adult stem cells in medicine in the future.



Activity AB1.12.1 Adult stem cells sheet 2

Embryonic stem cells Adult stem cells



Activity AB1.12.2 The cloning debate sheet 1

A: Cloning farm animals and animals for medicines
Cloning isn’t easy. It takes many attempts to clone a sheep or
cow successfully. But if the animal is particularly good, some
people think it is worth it. Some animals have been genetically
engineered so they make human medicines in their milk. These
animals have been cloned to get more ‘medicine makers’.
Some cloned animals – like Dolly the sheep – seem to have
aged very quickly and died young. Other cloned animals seem
young for their age. Scientists are still not sure of all the effects
of cloning on animals.

To find out
Find out as much as you can about the successes and failures
of cloning farm animals.

To do
Write a report on it for your local paper. Give two different
ethical positions on the cloning of farm animals.




B: Cloning pets
Most people are sad when a much-loved pet dies. Then, sooner
or later, they get another one. But, using modern cloning
technology, a few people have tried to keep their original pet
going for ever. They have had their cat or dog cloned, even
though it costs a great deal of money. So far, the owners are
delighted with their cloned pets – both dogs and cats have been
cloned. But, in fact, these clones will not be exactly the same as
the original animal. They have a different surrogate mother and
so will be brought up in a different way in their early weeks.
What is more, because of the way the coat colour develops in
cats, a cloned kitten may not even have the same colour
patterns and markings as the original animal!

To answer
1 Some people may be disappointed with their cloned pet.
a Suggest reasons why this might be.
b Do you think it is a sensible use of resources to clone
dead pets?
2 Many high-performance horses have been gelded, which
means they cannot reproduce.
a What are the advantages of cloning these horses?
b What might be the objections to this process?




C: Cloning endangered or extinct animals
In the famous film Jurassic Park, scientists extracted dinosaur
DNA from blood, found in mosquitoes fossilised in amber, and
cloned the prehistoric reptiles dinosaurs, including
Tyrannosaurus rex. Jurassic Park is pure fiction, but some
scientists think that it may be possible to clone animals which
have become extinct more recently. For example, a baby
mammoth was found almost perfectly preserved in the
permafrost of Siberia in 2007. It is just possible that, one day,
DNA from a fossil like this will be used for adult cell cloning,
with the embryo developing in the womb of a modern relative.
In the case of a mammoth, this would probably be an elephant.
Less science fiction and more science fact is the cloning of
endangered species, such as the guar and the mouflon. In a
number of cases, scientists have tried to clone animals which
are almost extinct to preserve their genetic material. So far,
they have had very limited success. Although some people are
still working on this technique, many scientists feel that the
money would be used more effectively trying to protect the
remaining members of the species and enable them to breed.
Tissue samples of many endangered species will be stored in
case cloning becomes more effective in the future.

To answer
1 Suggest some of the scientific problems with trying to clone
extinct animals.
2 Give ethical arguments for and against using cloning to:
a try to save endangered species
b try to bring back species that are already extinct.




D: Cloning humans
Scientists have cloned many different species of mammals
using adult cell cloning techniques. They include cats, mice,
dogs, horses, cows and sheep. However, no-one has yet
cloned a primate successfully, although some early embryos
have been developed.
The biggest hurdle of all will be cloning people. It will be very
difficult to do, both biologically and ethically.
Many people are completely against the idea of human cloning
for many different ethical and religious reasons.
Some people feel that cloning people may be used as another
way of helping infertile couples to have children.
Some people would like to have clones of themselves.
Because of the length of human lives, a clone would always be
much younger than the original person. Environment shapes
us as well as our genes. A different upbringing could produce a
very different person
Professor Giovanni Berlinguer, of Rome University, who is a
world expert in bio-ethics, is against human cloning. He also
believes it would not work as well as people might think…‘You
could clone a cell from Mother Teresa and give birth to a serial
killer.’

To do
Plan two short talks on human cloning.
• In one of them you will support the idea of human cloning.
Put forward as many arguments as possible to support
research into making it a success. You can use both
scientific and ethical arguments.
• In the other you will be against the idea of human cloning.
Put forward as many arguments as possible against allowing
research into human cloning to go ahead.



Activity AB1.A.1 Huntington’s disease

What happens to someone with the disease?
Symptoms usually begin between the ages of 35 and 50 years.
They develop slowly over the next 15 to 20 years.

The symptoms
At first people with the disease:
• become forgetful
• experience small, uncontrolled muscle movements
Later they have problems:
• concentrating
• speaking clearly
• controlling body movements
They become more and more disabled.

To answer
The diagram is a family tree.
It shows a family affected by Huntington’s disease.

1 Huntington’s is a genetic disease. What two things does the
family tree tell us about how the disease is passed on?
2 Look at Craig’s family tree Section B of your textbook.
a Eileen is very worried because David looks so like his
father. Why do you think she is so worried?
b Do you think she should be less worried about Sarah?
c Robert’s symptoms began when he was 56 years old.
Is this when Huntington’s disease usually gets noticed?

the Nuffield Foundation B1.A-3 in the purchaser’s school or college


Activity AB1.A.1 Huntington’s disease


the Nuffield Foundation B1.A-4 in the purchaser’s school or college


Activity AB1.B.1 Embryo selection is here to stay sheet 1

Match each item to the correct definition. One has been done for you.

‘designer babies’ A change in an allele.

In vitro fertilisation. Fertilisation happens by
mixing eggs and sperm in a laboratory. ‘In
HFEA
vitro’ means ‘in glass’. Embryos produced in
this way are sometimes called ‘test tube
babies’.

genetic modification or
engineering Embryos chosen because they have certain
features.

Human Fertilisation and Embryology
mutation Authority. This group decides what uses of in
vitro fertilisation are allowed.

genetic screening Cells that are unspecialised and can develop
into many other types of cell.

IVF Changing the genes in a cell. This is usually
done by introducing one or more alleles.

Testing a large group of people for alleles
Stem cells that cause genetic disorders.

the Nuffield Foundation B1.B-4 in the purchaser’s school or college



Embryo selection – here to stay
In 1989 scientists found the gene for Only embryos without the faulty gene
cystic fibrosis. Some said we were are chosen. Some people don’t agree
close to a cure. Fifteen years on we with choosing embryos. They say this
still don’t have one. method throws away human beings.
What doctors can do is test people for But embryos are a group of cells. They
the gene. They can test: aren’t conscious. Normally, IVF is
• parents (to see if they could pass the
used to help infertile couples. Embryos
gene on) are often destroyed then as well.
• unborn babies in their mother’s Foreign clinics let people use this
wombs method to choose the sex of their child.
• embryos made in the lab by IVF Soon they’ll be offering embryo
Testing unborn babies in the womb is testing for features like eye colour or
risky for baby and mother. It may also height.
mean that the parents choose a Couples that test the embryos for a
termination. disease gene are just giving their
So some people choose to fertilise the children a helping hand.
egg outside the woman’s body. This is
called IVF (in vitro fertilisation).
Embryos can then be tested before they
are put in their mother’s womb.

Word list
Fact Something that people accept as having been proved true.
Speculation Suggesting possibilities that might happen. Goes beyond known facts.
Opinion What someone believes is likely. May or may not be based on convincing
evidence.




To do
Read the article on sheet 2.
1 Underline in red a definition of in vitro fertilisation.
2 Underline in blue a description of choosing embryos based
on their genes.
3 In the first paragraph underline in two different colours:
• the fact that the cystic fibrosis gene was found in 1989
• the speculation that we were a great step closer to
treatment
Underline fact and speculation in the word list with the
same two colours.
4 In paragraph 5, underline in green two different opinions of
choosing embryos based on their genes. Underline opinion
in the word list in green.
5 Use the same colours to underline any other facts,
speculation, or opinions you can find in the article.

Optional
6 Choosing embryos based on their genes is called
pre-implantation genetic diagnosis (PGD). Summarise the
author’s views about the use of PGD.



Activity AB1.B.2 Inheriting gender

Human cells have 23 pairs of chromosomes in the nucleus.
One pair is the sex chromosomes. Males have XY
chromosomes. Females have XX sex chromosomes.
1 Draw and complete this table to show different sperm and
ova joining. Colour the squares that show females in one
colour and those that show males in another.

ovum Key
X X boy
sperm X
cell
Y girl

2 Some alleles are recessive. They only have an effect in
someone who inherits a copy from both parents.
An exception to this rule is in men when the gene is on the X
chromosome. Men only have one X chromosome so it takes
only one copy of a faulty allele to have an effect. Girls still need
two copies to be affected. We call girls with one allele for the
condition carriers because they can pass it on to their children.
Haemophilia and colour-blindness are two examples of
diseases carried on the X chromosome.
a Explain why about 1 in 12 males in the UK have some
degree of colour-blindness, but very few girls have.
b According to Jewish law, boy babies have their foreskins
removed. However, if a boy dies from bleeding following
this minor operation, his younger brothers and male
cousins are not circumcised. What does this tell you
about knowledge of haemophilia when this law was made
thousands of years ago?

c On the family tree above, which of the people are:
(i) haemophiliac (iii) possibly carriers of haemophilia
(ii) definitely carriers of haemophilia (iv) definitely not affected by haemophilia?



Activity AB1.B.2 Inheriting gender



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