b1 you and your genes worksheets

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B1.1-6

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.



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Activity AB1.1.2 Talking genes



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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



B1.2-6


Activity AB1.2.1 Cloning plants

sheet 1

Cloning cauliflower

To do Safety note: Take care when you are cutting samples.

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.

you MUST wear eye protection



B1.2-7


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.



B1.2-8


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.

Characteristic Identical twins reared together

Identical twins reared apart

Non-identical twins

Non-twin siblings

Height difference (cm)

1.7 1.8 4.4 4.5

Mass difference (kg)

1.9 4.5 4.6 4.7

IQ score difference 5.9 8.2 9.9 9.8

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?



B1.2-9


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.



B1.2-10


Activity AB1.2.2 Twin studies

This page is intentionally blank.



B1.3-4


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.



B1.3-5



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



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B1.4-6


Activity AB1.4.1 Male or female?

Sex chromosomes carried

Sperm cell Egg cell (ovum)

Fertilised egg 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.



B1.4-7


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.



B1.4-8


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.



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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.



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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.



B1.5-10


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.



B1.5-11


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.



B1.5-12


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?



B1.5-13


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.



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Activity AB1.5.4 Pairing up

sheet 1



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sheet 2



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sheet 3



B1.5-17


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.



B1.5-18


Activity AB1.5.5 Predicting inheritance sheet 2

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 %.



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sheet 3

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.



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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.



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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.



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sheet 6



B1.6-5


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.



B1.6-6


Activity AB1.6.1 Cystic fibrosis sheet 2

sheet 2

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 AB1.6.1 Cystic fibrosis



B1.6-7


Activity AB1.6.2 Two inherited conditions

sheet 1

Huntington’s disease

Cystic fibrosis



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Activity AB1.6.2 Two inherited conditions sheet 2

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 h = normal allele

F = normal allele f = cystic fibrosis allele

Do the parents of the affected people also have the disease?

yes/no yes/no

What are the allele pairs of people with the disease? HH or

What are the allele pairs of people without the disease?

Ff or

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.



B1.6-9


Activity AB1.6.2 Two inherited conditions sheet 3

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.

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.

one dominant recessive no will carrier



B1.6-10


Activity AB1.6.2 Two inherited conditions




B1.7-4


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.’



B1.7-5


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.



6

B1.7-6


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?



7

B1.7-7



Discuss these questions in your group.

Ask for any extra information that you need.

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8

B1.7-8



The coupleLaura’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 counsellorA 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.



9

B1.7-9


Activity AB1.7.3 Decision making

Summary flowchart: possible viewpoints



B1.7-10




B1.8-4


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.



B1.8-5



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.



B1.8-6






B1.9-3


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?



B1.9-4


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



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sheet 2

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



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sheet 3

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.



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Activity AB1.9.2 Stereotype of the karyotype sheet 4

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?



B1.9-8






B1.10-4


Activity AB1.10.1 How are embryos selected?




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

B1.10-5

sheet 1

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





B1.10-6

sheet 2

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.





B1.10-7

sheet 3

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1 2 3 4





B1.10-8

sheet 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.





B1.10-9

sheet 5

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.





B1.10-10




5

B1.11-5


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?



6

B1.11-6


Activity AB1.11.2 Stem cells sheet 1



7

B1.11-7


Activity AB1.11.2 Stem cells

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.

sheet 2

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.

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.



8

B1.11-8


Activity AB1.11.2 Stem cells sheet 3

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.



B1.11-9


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.

• Consider other views, describing evidence for and against.

• 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.

Arguments can be extremeviews, or more balanced.



B1.11-10


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:



B1.11-11


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.



B1.11-12



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



B1.11-13



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.



B1.11-14


Activity AB1.11.4 Planning your presentation

sheet 4

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 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.

For example:



B1.12-5


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.



B1.12-6


Activity AB1.12.1 Adult stem cells sheet 2

Embryonic stem cells Adult stem cells



B1.12-7


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.



B1.12-8



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?



B1.12-9



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.



B1.12-10



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.



B1.A-3


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?



B1.A-4


Activity AB1.A.1 Huntington’s disease




B1.B-4


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.

genetic modification or engineering Embryos chosen because they have certain

features.

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.

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

HFEA

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

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

mutation

‘designer babies’ A change in an allele.



B1.B-5



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.

Embryo selection – here to stay In 1989 scientists found the gene for cystic fibrosis. Some said we were close to a cure. Fifteen years on we still don’t have one.

What doctors can do is test people for the gene. They can test: • parents (to see if they could pass the

gene on) • unborn babies in their mother’s

wombs • embryos made in the lab by IVF

Testing unborn babies in the womb is risky for baby and mother. It may also mean that the parents choose a termination.

So some people choose to fertilise the 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.

Only embryos without the faulty gene are chosen. Some people don’t agree with choosing embryos. They say this method throws away human beings. But embryos are a group of cells. They aren’t conscious. Normally, IVF is used to help infertile couples. Embryos are often destroyed then as well.

Foreign clinics let people use this method to choose the sex of their child. Soon they’ll be offering embryo testing for features like eye colour or height.

Couples that test the embryos for a disease gene are just giving their children a helping hand.



B1.B-6



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.



B1.B-7


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

X sperm 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?



B1.B-8


Activity AB1.B.2 Inheriting gender


b1 you and your genes worksheets

Self Improvement