Genetik: Stundenentwürfe - Bildung stärkt Menschen
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Bildungsplan 2004 Allgemein bildendes Gymnasium Umsetzungsbeispiel für Biologie Bilinguales Modul für Klasse 10 Genetik Katrin Farian, Otto-Hahn-Gymnasium Ludwigsburg Kirsten Heckelmann, Königin-Olga-Stift Stuttgart Landesinstitut für Schulentwicklung Qualitätsentwicklung und Evaluation Schulentwicklung und empirische Bildungsforschung Bildungspläne November 2007 Genetik: Stundenentwürfe LEGENDE: Rot: Arbeitsaufträge, Fragen, Einleitungen Grün: Tafelanschrieb Blau: Neu einzuführende Wörter; Eventuell am rechten Tafelrand notieren. Pink: Wörter, die auf Extrablatt definiert werden (Anlage 26) Zeit 15’ STUNDE 1 Material 1. Einstieg AA: These baby pictures taken around the babies’ first birthdays. The top row shows two sets of parents and the bottom row shows 4 children – each set of parents has one child. Now look at the pictures closely and try to find out which of the four babies belongs to each couple. You can discuss your ideas with your partner. -Folie Eltern und Kinder (Anlage 1) -Gleiche Folie als Einzelbilder Schüler zeigen Lösungen an OHP. F: How did you come to your result? EA: hair colour, shape of face, nose etc. …. F: Why do children often look similar to/ resemble their parents? EA: because they get their genes/ chromosomes/ DNA F: So why don’t brothers and sisters look exactly the same? EA: because they have different genes/chromosomes/DNA F: Are there other factors that determine your looks besides your genes? (think of identical twins, hair dyeing etc.) EA: environment Weitere Wörter, die im Unterrichtsgespräch eingeführt werden können: inherit, trait 25’ TA: GENETICS: 1. Variation in plants and animals Genetic variation All organisms differ in looks and behaviour from each other because their genes are a bit different. exception: identical twins. Environmental variation = differences in looks and behaviour caused by differences in environment (upbringing, food, scars, hair styles). Example: identical twins with different hairstyles, weight, etc. Folie mit Zwillingen (Folie zeigen) Environmental variation is especially great in plants because they are (gutes Bild siehe Anmerkungen zur strongly affected by temperature and sunlight. Stunde) 2. Erarbeitungsphase 1: Genetic Material With all this talk about genes, chromosomes, DNA etc. let’s have a closer look at genetic material. F: What is this and where can you find it? (Folie zeigen) Folie mit Karyogramm (gutes Bild siehe Anmerkungen zur Genetik: Stundenentwürfe Stunde) Erarbeiten, dass es sich um 46 Chromosomen handelt, dass man 23 von Mutter bekommt und 23 von Vater, und 2 Geschlechtschromosomen hat. Sicherung: „Laufdiktat“ AA: Go to the posters and get information on genetic material. Make sure you have understood everything (Otherwise ASK!!!!) and try to remember as much as possible. Then go back to your seat and fill in the worksheet I ‘ll put there in the meantime. Überprüfung: Fragen zum AB: F: What can you find in the nucleus? F: How many chromosomes can you find in the nucleus? F: Why are there pairs of chromosomes? F: How is a chromosome built up? (Can you draw one?) F: What is a gene? F: Where in the chromosome can you find DNA? Infoblatt Genes, Chromosomes and DNA (laminiert und kopiert; Quelle siehe Anmerkungen zur Stunde) Arbeitsblatt (siehe Anmerkungen zur Stunde) Hausaufgabe: Revision Mitosis (What is it and how does it happen?) STUNDE 2 5’ Wiederholender Einstieg: Folie zeigen. Erst weibliches Karyogramm aufdecken, dann männliches. Folie mit 2 Karyogrammen (männlich und weiblich) F: What is this? What are the components? EA: Info zu chromosomes etc. (siehe letzte Stunde) F: What is the difference between the two karyograms? EA: one chromosome looks different, one is male one is female. Short explanation of x and y chromosomes (names, “It’s the y that makes the guy.”) 15’ Erarbeitung Gameten: Leserbrief (Anlage 2) Leserbrief vorlesen; vorher heir und duty einführen You might agree with John Stinemyer that this is indeed unfair to Princess Masako, but to really judge this, one needs to know if men or women are responsible for the sex of the baby. Look at the diagram on the worksheet that will show you how the sex chromosomes are passed on from parents to their children and find out who is responsible. vorher: gametes einführen Arbeitsblatt: boy or girl (Anlage 3) Überprüfung: an Folie zeigen lassen wie es zu einem Mädchen und einem Jungen kommt. © Katrin Farian und Kirsten Heckelmann 2007 2 Genetik: Stundenentwürfe 20’ Wdh Mitose Hier bieten sich verschiedene Methoden zur Wiederholung an. Je nach Einführung des Themas kann man schon bekannte (oder neue) Tafelmodelle benutzen. Eine gute Möglichkeit bieten sicher auch Chromosomen aus Draht an Hand derer die Schüler die Mitose nachstellen. eventuell Drahtchromosomen (siehe Bild in Anmerkungen) STUNDE 3 5’ Einstieg Meiose: F: “All body cells have 46 chromosomes- true or false?” Falls Schüler nicht auf das Konzept der Chromosomenanzahlhalbierung bei Gameten kommen, Denkbeispiel anführen: What would happen if both parents passed on all their chromosomes? 30’ Erarbeitung Meiose Die Schüler bearbeiten mit Hilfe von http://www.contexo.info/DNA_Basics/Meiosis.htm das Arbeitsblatt “Meiosis- or how are gametes made?“. 10’ Internet Arbeitsblatt “Meiosis – or how are gametes made?” (Anlage 4) Erarbeitung/ Sicherung/Vertiefung Meiose Computerraum Die Besprechungsphase (in dieser und der nächsten Stunde) sollte an die jeweilige Klassensituation angepasst werden. Besonders der Unterschied zwischen Meiose I und II sollte noch einmal verdeutlicht werden. Die medialen Voraussetzungen im Computerraum können sehr gut genutzt werden. So kann der Meiosefilm mehrfach gezeigt werden. Eine interessante Vertiefungsaufgabe ist es zum Beispiel die Schüler den Ton zum Meiosefilm selber sprechen zu lassen. Dies kann auch in Partner- oder Gruppenarbeit erfolgen. STUNDE 4 ca. 25’ Erarbeitung/ Sicherung/Vertiefung Meiose siehe Stunde 3 20’ Vergleich Mitose/ Meiose AA: Now that you have got to know both the processes of mitosis and meiosis you should be able to compare them. Please write down difference and similarities.(7 minutes) Similarities: • In both the nucleus and cell divides and new daughter cells are produced. • Both processes include the steps of mitosis (Meiosis II = a form of mitosis). • In both processes spindle fibres are built to pull chromosomes/ chromatids apart. © Katrin Farian und Kirsten Heckelmann 2007 eventuell den Schülern noch einmal eine Zeichnung kopieren, die beide Vorgänge zeigt. 3 Genetik: Stundenentwürfe Differences: • Daughter cells in meiosis are haploid and diploid in mitosis. • Meiosis 1 separates homologous chromosomes while Mitosis separates 2 chromatids. • In Mitosis the daughter cells have the same genetic information as the “mother cell”. In meiosis the chromosomes are newly combined = daughter cells (after Meiosis I) have different genetic information. STUNDE 5 25’ Erarbeitungsphase 1 – 1. Mendelsche Regel In dieser Stunde wird mit folgender Website gearbeitet: http://www.cambridgeassessment.org.uk/ca/Initiatives/Detail/Simulatio n_-_Rabbit_Genetics Computer mit Internetanschluss/ Beamer Let’s breed rabbits. We’ll take this beautiful white rabbit that comes from a family of white rabbits (parents and all its brothers and sisters are white) and cross it with a black rabbit that comes from a family of black rabbits. Q: What colour do you expect their children to have? Why? Die Kreuzung mehrmals vormachen am Computer (mehrmaliges „Breed“ klicken). (Vielleicht schon Wörter für erste Mendelsche Regel einführen – siehe unten) Q: Since we get the same results any time we repeat the cross, there seems to be a kind of rule. We call it Mendel’s first law: Try and formulate it. (maybe with your partner.) Hier bietet es sich an, kurz ein Bild von Gregor Mendel zu zeigen und zu sagen, wann er lebte. Nähere Informationen bekommen die Schüler in Stunde 7. Folie: Bild Gregor Mendel Mendel’s first law In a cross of parents that are pure for contrasting traits (in this case colour of fur), only one form of the trait will appear in the next generation. Offspring that are hybrid for a trait will have only the dominant trait in the phenotype. Q: Which one is the dominant trait here? EA: black fur Remember the diagram (“Kreuzungsschema”) we drew when determining the sex of the offspring. Let’s draw one for this cross: TA: © Katrin Farian und Kirsten Heckelmann 2007 4 Genetik: Stundenentwürfe Folgendes Fachvokabular muss noch eingeführt werden (lässt sich gut anhand des Kreuzungsschemas erklären): genotype, homozygous, heterozygous, allele 1. Mendelsche Regel oder Uniformitätsregel: Kreuzt man zwei Individuen einer Art, die sich in einem Merkmal unterscheiden, das beide reinerbig aufweisen, so sind die Nachkommen in der F1-Generation im betrachteten Merkmal uniform. 20’ Erarbeitungsphase 2 – 2. Mendelsche Regel Now let’s take two of the offspring and cross them. But first you (and your partner) should predict the outcome with the help of a diagram (“Kreuzungsschema”). Demonstration am Computer und Anzeichnen des Kreuzungsschemas an der Tafel. TA: Mendel’s Second Law © Katrin Farian und Kirsten Heckelmann 2007 5 Genetik: Stundenentwürfe In a cross of the hybrids of the F1-generation, the traits of the original parents will appear in the F2-generation in a 3:1 ratio. Definition: recessive 2. Mendelsche Regel oder Spaltungsregel: Kreuzt man die vorgenannten Mischlinge der F1 - Generation untereinander, so spalten im dominant rezessiven Fall in der F2Generation die Merkmale im Zahlenverhältnis 3 : 1 wieder auf. HA: Fragen auf HP: Vocabulary Review http://www.hobart.k12.in.us/jkousen/Biology/mendel.htm STUNDE 6 Abfrage der HA Einführung des Punnett Square: In dieser Stunde sollen die Schüler das „Punnett Square“ als Alternative zum Kreuzungsschema kennen lernen. Man kann es entweder im Lehrervortrag ähnlich wie auf folgender Website einführen oder die Schüler können es sich anhand selbiger Website selber erarbeiten. http://users.adelphia.net/~lubehawk/BioHELP!/psquare.htm Computerraum Übungen: Es stehen je nach Zeit und Interessenslage der Schüler folgende Übungen zur Verfügung: 1. http://www.hobart.k12.in.us/jkousen/Biology/mendel.htm Review Question 1-14 2. Arbeitsblatt siehe Anlage 5 3. Genetic Eye colour calculator: http://museum.thetech.org/ugenetics/eyeCalc/eyecalculator.html STUNDE 7 15’ Who was Gregor Mendel – Listening Comprehension Das Bild Mendels noch einmal auflegen und die Im Text markierten Wörter einführen. Text einmal vorlesen. Beantworten und Besprechung der Frage 20’ Text: „Who was Gregor Mendel?“ Eventuell Fragen auf Folie (Anlage 6) Erarbeituung dihybrider Erbgang: AA: Today we are going to breed mice and we’ll have a look at two traits like Mendel did with his peas. We have mice with white and black © Katrin Farian und Kirsten Heckelmann 2007 6 Genetik: Stundenentwürfe fur and mice with black and red eyes. The black fur and the black eyes are dominant alleles. We’ll take two mice with black fur and black eyes and we’ll cross them. AaBb x AaBb (A= black fur, a = white fur; B= black eyes, red eyes) Klasse für die folgende Partnerarbeit in zwei Gruppen einteilen. Group 1: Use a Punnett square to find out which genotypes and phenotypes the children of these mice will have. Group 2: Take 4 coins. Label two with B on one side and b on the other and two with A on one side and a on the other. One A and one B coin represent the alleles coming from one parent. Now throw the coins at least twenty times and record the different genotypes the “children” have. Work out how many times each phenotype appears. Ein Schülerpaar der Gruppe 1 stellt Ergebnis vor (auf Folie) und das Verhältnis der verschiedenen Phänotypen wird notiert. Anschließend stellen die Schüler der Gruppe 2 ihre Ergebnisse zum Vergleich vor. Folien, Folienstifte The ratio of phenotypes determined by drawing a Punnett square shows how high the probability is that the children will be of a certain phenotype. The more offspring is produced during a cross the closer the ratio of phenotypes is to the predicted number. 10’ Erarbeitung Mendelsche Regel 3 One of the questions Mendel asked himself was whether two traits were passed on to the next generation independently or dependent on each other. By looking at the results of today’s cross, write down a short answer for Mendel. Mendel’s third law: The Law of Independent Assortment Alleles for different traits are distributed to sex cells (& offspring) independently of one another. Dritte Mendelsche Regel oder Regel von der Unabhängigkeit der Erbanlagen: Die einzelnen Erbanlagen werden unabhängig voneinander vererbt und bei der Keimzellenbildung neu kombiniert. STUNDE 8 Einstieg 20’ AA: Today we are going to find out how some specific traits we all have or do not have are inherited. The first trait is rolling your tongue! Schüler probieren, ob sie ihre Zunge rollen können. Kurz über Ergebnis © Katrin Farian und Kirsten Heckelmann 2007 7 Genetik: Stundenentwürfe sprechen. AA: I have a letter written by a girl called Tanja. She tells her friend Sandra about meeting her relatives and how they all tried to roll their tongues. I will read the letter to you and two of you will put the pictures of Tanja’s relatives on the board. Brief vorlesen, Schüler heften Bilder an Tafel (eventuell vorher Anweisung geben: für jede Generation von unten beginnend neue Ebene anfangen) AA: What we can see on the board is a family tree showing us who can roll their tongue and who can not. Using pictures all the time would be too complicated so there are symbols to represent men and women, who carries the characteristic or not and so on. We are going to copy this family tree with the help of these symbols! letter (siehe Anlage 7) pictures of relatives (zwei Farben für Merkmalsträger/NichtMerkmalsträger) (Quelle siehe Anmerkungen) TA: Family trees Erarbeitung: Art der Vererbung Zungenrollen und Form der Ohrläppchen 25’ AA: There is a second characteristic some of you will have or not have. It is to do with the shape of your earlobes. Folie zeigen, long = angewachsen, round = frei erklären und einzeichnen, eventuell Ergebnis festhalten, wie viele Schüler welche Form haben AA: We still do not know how we inherit these characteristics…. Lehrer teilt Klasse in zwei Hälften ein, Kleingruppen beschäftigen sich entweder mit dem Erbgang des Zungenrollens oder der Form der Ohrläppchen Ergebnissicherung: Vorstellen der Ergebnisse mit Folien, jeweils andere Gruppe übernimmt den fehlenden Teil © Katrin Farian und Kirsten Heckelmann 2007 Folie: Shape of earlobes (Anlage 8) Arbeitsblatt: “Are you a tongue roller” (Anlage 9) und “What shape are your earlobes?” (Anlage 10) Folien: wie Arbeitsblätter und Folienstifte 8 Genetik: Stundenentwürfe Mögliche HA: Schüler sollen die jeweiligen Stammbäume für ihre Familie zeichnen Vokabelblatt (Anlage 11) Vorbereitende HA: Vokabelblatt „Hereditary diseases“ lernen STUNDE 9 und 10 Thema: Hereditary diseases Lehrer führt Wort ein und gibt bekannt, dass eine Tagung zum Thema Erbkrankheiten stattfindet. Die Klasse wird in Vierergruppen (= university teams, Stammgruppe) eingeteilt, überzählige Schüler werden den bestehenden Gruppen zugeordnet. Lehrer teilt den Gruppen einen Umschlag aus, in denen sich die Einladung zur Tagung und das Material befindet und verweist auf aushängende Zeitpläne im „Kongresszentrum“ (Pläne aushängen, wo welcher Workshop stattfindet und in welchem Zeitrahmen sich die einzelnen Schritte des Gruppenpuzzles abspielen werden). Alternativ kann die Einladung, auf der der Ablauf beschrieben ist, auch gemeinsam mit der Klasse besprochen werden. Danach verteilen sich die Schüler auf die Expertengruppen (=Workshops), erarbeiten jeweils eine Erbkrankheit. und stellen diese anschließend ihrer Stammgruppe vor. Dafür liegen in den Workshops auf A3 kopierte Stammbäume der jeweiligen Erbkrankheit aus. Wenn nötig, können auch die Erklärungen der jeweiligen Erbgänge nachgereicht werden. Alle Schüler haben am Ende die Übersichtstabelle für die vier Krankheiten ausgefüllt. Zum Schluss findet eine Live Show im Fernsehen statt. Jeweils ein Experte aus den Workshops stellt sich den Fragen der Zuschauer (=restliche Schüler, die Fragen vorbereitet haben), ein Schüler ist „host“ und koordiniert die Sendung. © Katrin Farian und Kirsten Heckelmann 2007 Umschläge (ev. mit Namen bekannter englischer/ amerikanischer Unis) mit: - letter of invitation (Anlage 12) - expert sheets (Anlagen 13-16) - worksheets (table) (Anlage 17) - Stammbäume mit Arbeitsaufträgen (Anlage 18-21) - nach Bedarf Erklärung der Erbgänge austeilen (Anlage 22-25) 9 Genetik: Anlagen Anlage 1: Which of these babies belongs to which set of parents? Parents as babies: Couple 1 Couple 2 The Babies: Mika Tom © Katrin Farian und Kirsten Heckelmann 2007 Elias Samuel 10 Genetik: Anlagen Anlage 2: Leserbrief In your article on the birth of Japan’s new prince, Hisahito, you mentioned that he is the new heir to the throne even though he is only the crown prince’s nephew. His aunt, crown princess Masako – it is said – couldn’t perform her traditional duty to give birth to a boy who can be the heir to the throne. Don’t you realize that this is absolutely not Princess Masako’s fault. It was her husband, Prince Naruhito, who determined the sex of their only child – a sweet daughter. It is all his fault. John Stinemyer © Katrin Farian und Kirsten Heckelmann 2007 11 Genetik: Anlagen Anlage 3: BOY or GIRL? Whose “fault” is it? 1 This diagram shows the way the male XY chromosomes and the female XX chromosomes are separated to form the gametes (egg cells and sperm cells). It also shows the possible ways the egg cells and sperm cells can come together at fertilisation. The lines between “possible gametes” and “possible children” show all the possible combinations. Remember, only one of these can happen per child/ offspring. ANSWER: The ______________ is responsible for the sex of the child because……….. 1 Slightly adapted from Parsons, Richard (ed.): GCSE Double Science Biology. Kirkby-in-Furnes: Coordination Group Publications 2001, p. 61. © Katrin Farian und Kirsten Heckelmann 2007 12 Genetik: Anlagen Anlage 4: MEIOSIS 1. General Questions With the help of the following webpage: http://www.contexo.info/DNA_Basics/Meiosis.htm answer these questions: 1. What is a diploid cell? What is a haploid cell? 2. Why do gametes need to be haploid? 3. What is the process called that produces haploid gametes? Copy the definition of this process. 2. The process of meiosis Have a look at the photographs and drawn pictures below. They are taken during the process of meiosis. They are not in the right order. Match them with the descriptions of the different phases below. Dear teacher, you can find a good photograph showing the stages of meiosis on this page: http://homepage1.nifty.com/scil la/sonota/ityou/ityou.html (you will only have to scramble the pictures). 1. Prophase The nuclear membrane starts to form and the chromosomes begin to coil up and move to the cell’s equator. There the homologous chromosomes “lie” next to each other and form a so-called tetrad. 2. Metaphase The spindle fibres begin to form and the chromosomes attach to the spindle fibres at their centromeres. 3. Anaphase The tetrads are now separated that means that the homologous chromosomes of each pair move to two opposite poles of the cell. 4. Telophase Now there are 23 chromosomes at each pole and two haploid cells begin to form. 5. Prophase II In the two daughter cells the 23 chromosomes move to the new cells’ equators. 6.Metaphase II The spindle fibres begin to form and the chromosomes attach to the spindle fibres at their centromeres. 7. Anaphase II The chromatids of each chromosome separate and are pulled along the spindle fibres to the opposite poles of the cells. 8. Telophase II The membranes of the new cells form and we nearly have 4 new haploid cells with 23 chromatids each. 9. We have 4 gametes. © Katrin Farian und Kirsten Heckelmann 2007 13 Genetik: Anlagen Anlage 5: In a very small area in a park there live many brown deer and some black deer. Altogether the black deer make up 9% of the population. The male deer is the father of all the fawns (=baby deer). a.) Is the black fur colour a dominant or a recessive allele? Give reasons for your decision. b.) Give the genotype of the male deer, female deer and all the fawns. Back up your answer by drawing the Punnett Squares. © Katrin Farian und Kirsten Heckelmann 2007 14 Genetik: Anlagen Anlage 6: Who was Gregor Mendel? 1 Today Gregor Mendel is known as the “father of genetics”, but back in his days nobody really cared about his experiments and certainly no one recognized how important his findings were. Gregor Mendel was born on July 22, 1822 in Austria as Johann Mendel. Johann was a brilliant pupil and even though his family was poor and could hardly pay for his schooling, he was able to attend the “Gymnasium” 36 kilometres from his home. In 1841, Johann started studying philosophy in Olomouc (Czech republic). He studied there for two years and then, one of his teachers suggested that Johann became a monk. So Johann became a monk in 1843, at 21 years of age. As the tradition goes, he got a new name, Gregor. Every morning, Gregor got up at six o’clock and went straight to the library to study. He studied religion and natural sciences. He also taught Latin, Greek, and mathematics to pupils at school. But Mendel didn’t pass his exams and after studying in Vienna for two more years he decided to start breeding plants instead. Mendel chose the garden pea to experiment on. First he chose seven characteristics to look at, for example the position of the flowers on the stem and the shape and color of the ripe seed. Then he planted his first generation of peas and watched them grow. For two years he kept planting the seeds to make sure they weren’t hybrids, that is, they always produced offspring that had the same characteristics as their parent plants. Then he began his experiments. The first of the experiments that he carried out crossed plants with round seeds and plants with wrinkled seeds. The resulting plants produced all round seeds! The next year he grew plants from these round seeds and crossed them to produce more seeds. This time there were 5474 round seeds and 1850 wrinkled seeds, making a 3:1 ratio of round to wrinkled seeds. Mendel was fascinated! It seemed that the wrinkled trait, which seemed to have disappeared in the first generation of offspring, reappeared in the second generation. He called the round trait "dominant" and the wrinkled trait "recessive". Mendel repeated the experiment with the other six characteristics and got the same 3:1 ratios. He also tried crosses looking at two different characteristics at the same time and got very interesting results. By 1863, Mendel’s experiments with peas were finally complete. He didn’t know what genes or chromosomes were, but he knew that every plant had two factors that were responsible particular trait and he knew that you inherited one factor from each parent. He learned that these factors could be dominant or recessive. Later on he didn’t have as much time for his plants, but he did carry out some more experiments using for example beans to confirm the results of his experiments with peas. 1 Slightly adapted from http://web.pdx.edu/~cruzan/Kid's%20Mendel%20Web/Johann%20Mendel.htm © Katrin Farian und Kirsten Heckelmann 2007 15 Genetik: Anlagen In 1865 Mendel gave two talks about his experiments, but people thought his talks were boring because no one understood his findings . His results were published the following year but few people read them. On January 6, 1884 he died and his work was forgotten until in 1900 three biologists, Carl Correns, Hugo de Vries, and Erich Tschermak, working independently, rediscovered Mendel’s laws. They were surprised to find that a monk, who had died 15 years earlier, had already published their discoveries. Today Mendel’s work is known all over the world and has inspired generations of modern scientists. Mendel truly is the Father of Genetics. Questions: Why did Mendel change his name from Johann to Gregor? What was the first cross Mendel carried out? Which trait was dominant? Name some disappointments in Mendel’s life. What happened in 1900? © Katrin Farian und Kirsten Heckelmann 2007 16 Genetik: Anlagen Anlage 7: Dear Sandra, last week our yearly „party for all the relatives“ took place which I hadn’t really looked forward to. I’m sure you remember how I annoyed I always get at Uncle Peter and the way he compares everybody to himself and starts criticising people,. This year, however, the party was really funny. It was already quite late when Jana, our youngest started babbling nonsense and started to roll her tongue over and over again. Her older brother Stefan then tried copying her funny tricks but failed even though he made every effort to roll his tongue just like her. Watching him trying was so funny and inspired all the family members to try to roll their tongues. That was really amusing and got everybody in the right party spirit. What was really strange though was that not everybody could roll their tongue. Jana and Stefan’s mother Susi can not roll her tongue while their dad Peter is a real pro at it. Maybe mother Susi comes after her parents Grandpa Berthold and Grandma Hanna, who both just had their tongues hanging out flat as they tried to demonstrate a beautiful tongue roll to us. This made Grandpa Berthold’s sister triumphant – she could roll her tongue and showed her masterpiece to everyone. “Sure – Greatgranddad August and greatgrandma Therese said., “Bertha is our daughter and we are both expert tongue rollers.” Apparently the ability to roll one’s tongue is inherited as a gene. I don’t know how this inheritance works and if there are any rules. Maybe you can help me? Love Tanja © Katrin Farian und Kirsten Heckelmann 2007 17 Genetik: Anlagen Anlage 8: What shape are your earlobes? © Katrin Farian und Kirsten Heckelmann 2007 18 Genetik: Anlagen Anlage 9: Are you a tongue roller? Alleles: A a 1. Is the gene for the characteristic “tongue roller” dominant or recessive? Find out with the help of the family tree! 2. Give the genotype for each member of the family tree. For which members can you not determine the genotype exactly? 3. Present your findings to the class! © Katrin Farian und Kirsten Heckelmann 2007 19 Genetik: Anlagen Anlage 10: What shape are your earlobes? Alleles: B b 1. Is the gene for the characteristic “long earlobe” dominant or recessive? Find out with the help of the family tree! 2. Give the genotype for each member of the family tree. For which members can you not determine the genotype exactly? 3. Present your findings to the class! © Katrin Farian und Kirsten Heckelmann 2007 20 Genetik: Anlagen Anlage 11: Vocab sheet: Hereditary diseases albinism Albinismus cystic fibrosis Mukoviszidose haemophilia Bluterkrankheit (the) Marfan syndrome Marfansyndrom to affect beeinflussen, beeinträchtigen, betreffen mammal Säugetier ethnic group ethnische Gruppe, Volksgruppe approximately ungefähr life expectancy Lebenserwartung to vary abweichen, variieren, wechseln vision Sehkraft, Sichtvermögen to be sensitive to sth. empfindlich auf etw. reagieren to suffer from leiden an/unter short- or long-sightedness Kurz-/Weitsichtigkeit to adapt to sth. sich an etw. anpassen disability (Körper)Behinderung, Unvermögen magnifier Lupe, Vergrößerungsglas Operation, Behandlungsraum, Sprechzimmer surgery mucus gland Schleimdrüse lining Schleimhaut Proteins that speed up reactions (e.g. in our enzyme body). pancreas diarrhea malnutrition sufferer drugs to require sth. to be affected by blood clotting factors bruising nosebleed internal bleeding joint soft tissue injection genetic engineering to donate blood contaminated connective tissue height /ηαΙτ/ spine to be more/less likely to tear /τε≅/ X-rays, to x-ray blood pressure to raise pregnancy © Katrin Farian und Kirsten Heckelmann 2007 Bauchspeicheldrüse Durchfall Fehlernährung s.o. who suffers from a disease hier: Medikamente, Arzneimittel etw. erfordern von etw. beeinflusst/betroffen sein Blutgerinnungsfaktoren blauer Fleck, Bluterguss Nasenbluten innere Blutung Gelenk die Weichteile Spritze, Injektion Gentechnik Blut spenden verunreinigt, verseucht, verschmutzt Bindegewebe Größe Wirbelsäule mehr/weniger wahrscheinlich sein (zer)reißen Röntgenstrahlen, röntgen Blutdruck erhöhen Schwangerschaft 21 Genetik: Anlagen Anlage 12: Dear Sir or Madam, I´m happy to be able to invite you to our “Genetics Congress”. There will be several workshops, all on different aspects of this year’s topic “Hereditary Diseases”. Your university can send a team of four scientists to participate in the four different workshops which are “A: Cystic fibrosis”, “B: Haemophilia”, “C: Albinism” and “D: The Marfan syndrome”. Enclosed you find the material with all the information you need to participate in your particular workshop successfully. Each of the four scientists of your university should decide on one workshop they want to participate in! Please read the schedule carefully to ensure the programme takes place without any disturbances: Morning 1. You have to decide who wants to participate in which of the four workshops. Your university team has to make sure it sends at least one specialist to each of the workshops. 2. You meet the other members of your workshop and discuss important matters of your topic. You are asked to fill in a form you will find enclosed in this envelope answering questions on the disease, its characteristics and way of inheritance, symptoms and treatment in keywords. Afternoon 3. After the lunch break you are kindly asked to inform your university team about the outcome of your workshop by explaining your results. All the scientists in your team should know about all the four diseases discussed at this year’s congress. 4. Afterwards there will be a live programme on TV, featuring the outcome and results of our congress. A group of four specialists will answer the questions put forward by the other scientists and the audience. In your workshop you should decide on who will be this specialist. All the other scientists please make sure to have two questions on the diseases ready each. I hope you will have a nice stay and enjoy the congress! © Katrin Farian und Kirsten Heckelmann 2007 22 Genetik: Anlagen Anlage 13: Albinism A common term to call someone with albinism is “albino”, but this word is not very nice and the correct terms would be “albinistic” or a “person with albinism”. People suffering from albinism have little or no pigment 1 and the disease can affect the skin, eyes and hair or only the eyes. The disease is known in humans as well as in animals like mammals, birds, reptilians, amphibians and fish. People of all ethnic groups can have albinism and in Germany there are approximately 5000 people with albinism. If they don’t live in tropical countries they have a normal life expectancy. The word albinism refers to different kinds of the hereditary disease. While one type affects primarily the eyes, the other one involves eyes, hair and skin. With both types the amount of pigment produced can vary. It is a myth that people with albinism have red eyes, most of them have blue or brownish eyes. But an albinistic person’s eye might appear reddish because the coloured part of the eye called iris can have so little pigment that it has almost no own colour and you can see the blood vessels 2 at the back of the eye. What all albinistic people have, though, are different kinds of vision problems. Normally, the iris helps control the amount of light coming into the eye by making the pupil wider or more narrow. But since the iris doesn’t have enough colour a lot more light can enter which makes the eyes of an albinistic person more sensitive to light. Other problems someone with albinism may suffer from include short- or longsightedness or “crossed eyes” 3 . This is due to an abnormal development of the retina 4 and nerve signals following wrong pathways from the eye to the brain. The pigment melanin also helps protect the skin from harmful sun rays5 . For an albinistic person whose skin is also involved this means that their skin cannot protect itself and they don’t tan 6 . So depending on how little melanin is produced, people with albinism can more or less adapt well to their disabilities. They have to wear dark sunglasses, protect their skin with sunscreen 7 and long clothes and many of them wear glasses. Some of them wear coloured contact lenses and some have to use hand-held magnifiers or special optical aids 8 that work like a telescope. For some eye surgery can help improve their disease. 1 Pigments give colour to plant or animal cells. They often function as a protection mechanism for the organism, e.g. the pigment melanin in our skin protects us from harmful UV rays. 2 Blutgefäße 3 to be cross-eyed = schielen 4 Netzhaut 5 Sonnenstrahlen 6 braun werden 7 Sonnenschutz, Sonnencreme 8 optische Hilfsmittel © Katrin Farian und Kirsten Heckelmann 2007 23 Genetik: Anlagen Anlage 14: Cystic Fibrosis (CF) Cystic fibrosis, also called CF or mucoviscidosis, is a hereditary chronic disease. Approximately 70,000 people suffer from CF worldwide and life expectancy has now risen to an average of 37 years because of better research and medical treatment. In Germany about 700 children are born with CF every year. The disease is caused by a mutation1 in a gene that controls the mucus glands. This defect makes the body produce very thick and sticky 2 mucus which affects the lungs and the digestive system. It also causes very salty-tasting skin. The body produces mucus to protect and lubricate 3 the linings of for example the digestive and the respiratory system. If the mucus in your body is thick and sticky it can block your airways. This leads to problems with breathing, a constant cough, bacterial lung infections and if it is not treated to permanent lung damage. The digestive system is affected by the mucus reducing the enzyme production in the pancreas. These enzymes help to break down food, so if there is not enough enzymes your body cannot use the food you eat properly. So you will lose weight and often you will also suffer from poor growth, diarrhea and malnutrition. So how does CF affect the daily life of sufferers and how can you treat it? Since CF is a chronic disease it is impossible to cure it, but normally the progress 4 of the disease can be slowed down. People suffering from it need a strict daily routine. First of all they need to watch what they eat. They need a high-calorie, high-fat diet with extra vitamins. Another aim is to reduce lung infections, so sufferers from CF normally have to inhale5 drugs every day, using a special machine. Of course they are not allowed to smoke and they have to keep their environment smoke-free because passive smoking is especially harmful. But often this is not enough and they have to take antibiotics 6 as well. Since bacteria can generally stay in the thick mucus a lot easier, they have to keep clean everything they come in contact with, for example by wiping 7 door handles etc. This of course requires a good general hygiene 8 . 1 A mutation is a change in the genetic information, they can be caused by mistakes in the DNA copying, by environmental factors or when the chromosomes are not distributed properly. Mutations can cause harm or give an advantage to an organism. 2 klebrig, zäh 3 fetten, ölen, schmieren 4 Fortschritt, Fortschreiten 5 inhalieren 6 Antibiotika 7 abwischen 8 /ηαΙδΖι:ν/ © Katrin Farian und Kirsten Heckelmann 2007 24 Genetik: Anlagen Anlage 15: Haemophilia Haemophilia is a hereditary chronic disease. It is also known as the “royal disease” since it runs in many European royal families such as the English, Spanish or Russian crowns. Approximately 5000 people in Germany suffer from it. The disease occurs worldwide (about 400 000 sufferers) and all ethnic groups are affected. In people with haemophilia special proteins called blood clotting factors are either partly or completely missing so they bleed for longer than normal. Since there is no permanent treatment available to replace or increase the clotting factor level the disease often causes difficulties with education or employment. The symptoms of haemophilia vary depending on how much clotting factor a person has. Normally any bleeding from cuts and injuries continues for much longer, a person with haemophilia may also experience unexplained bruising or nosebleeds. The main problem are not any cuts, though, but internal bleeding into joints, muscles and other soft tissue which occurs with worse forms of haemophilia. These bleeds can occur because of injuries or spontaneously. How bad the bleeding is- and the damage caused by it- depends on the amount of clotting factor. If left untreated internal bleeding can cause bad pain or even permanent damage of joints like arthritis 1 or stiffness of knees, elbows, ankles 2 , shoulders and wrists 3 . But also around one third of female carriers have low clotting factor levels and have symptoms like males with mild forms of the disease. They might also suffer from heavy periods and might need treatment in case of surgery or childbirth. So how does haemophilia affect the daily life of sufferers and how can you treat it? As mentioned above haemophilia is a lifelong disease which cannot be cured permanently. To help prevent some of the bleeding the missing clotting factor can be replaced by injections on a regular basis several times a week for bad forms of the disease. People with more moderate 4 forms will have to carry around injections with them in case a bleed occurs or immediately go to the hospital for an injection if they injure themselves. The clotting factor for these injections is now partly produced by genetic engineering or the blood is treated chemically. But until the late 1980s a lot of the blood donated was contaminated. Thousands of people got HIV or Hepatitis C which affects the functioning of the liver. Many of them died as a consequence. 1 2 3 4 Arthritis, entzündliche Erkrankung der Gelenke Knöchel Handgelenke gemäßigt, (mittel)mäßig © Katrin Farian und Kirsten Heckelmann 2007 25 Genetik: Anlagen Anlage 16: The Marfan syndrome The Marfan syndrome is a hereditary chronic disease affecting about 1 person in 10000. The disease occurs worldwide and among all ethnic groups. It is caused by a problem with chromosome 15 which helps making connective tissue in our body. Connective tissue provides support and shape to the body. In people with Marfan this tissue isn’t formed properly and therefore not as strong. The symptoms of the Marfan syndrome vary depending on how bad the case is. Almost all people who have it have similar traits like long legs, fingers and toes. Often their arm span 1 is bigger than their height while for most healthy people these are the same. Since their connective tissue is weaker than normal their hands for example are a lot more flexible and they can bend their fingers back very far. But this also causes their joints to be loose and their spine to be curved from side to side as well which causes bad pain. Apart from other symptoms like several different eye problems, a narrow face and mouth and a caved-in 2 or pushed-out breastbone3 , people with the Marfan syndrome suffer from less elastic lung tissue 4 causing the lung to collapse and also from heart problems which are probably the most dangerous symptoms of the disease. Since the walls of the main blood vessels are weakened they get wider especially when a lot of blood is transported. This is the case for the aorta, the main artery leaving the heart. The more blood is pumped through the blood vessels 5 the more likely the walls are to tear, causing blood to flow through these tears which can be deadly. So how does the Marfan syndrome affect the daily life of sufferers and how can you treat it? Since it is a chronic disease it is impossible to cure it. Treatment involves regular visits with a doctor to check the heart. X-rays of the chest may also be needed on a regular basis. Some people with Marfan have to take drugs for their heart rate and blood pressure. Sometimes heart surgery is needed. The condition has also effects on your daily life since physical exercise 6 raises the blood pressure and more blood is transported through the blood vessels. This might be dangerous so sufferers should avoid too much exercise. They are not recommended to play any team sports. For women with heart problems pregnancy and childbirth isn’t advised because it also causes more stress to the heart. 1 2 3 4 5 6 Armspanne eingefallen Brustbein Lungengewebe Blutgefäße körperliche Betätigung, Bewegung © Katrin Farian und Kirsten Heckelmann 2007 26 Genetik: Anlagen Hereditary diseases Anlage 17: name of disease, basic information way of inheritance (dominant, recessive etc.) © Katrin Farian und Kirsten Heckelmann 2007 causes and symptoms 27 treatment and effects on daily life Genetik: Anlagen Anlage 18: Albinism Use this family tree in your workshop to analyse how albinism is inherited and later to explain it to your university team! - 21: © Katrin Farian und Kirsten Heckelmann 2007 28 Genetik: Anlagen Anlage 19: Cystic fibrosis Use this family tree in your workshop to analyse how cystic fibrosis is inherited and later to explain it to your university team! © Katrin Farian und Kirsten Heckelmann 2007 29 Genetik: Anlagen Anlage 20: Haemophilia Use this family tree in your workshop to analyse how haemophilia is inherited and later to explain it to your university team! © Katrin Farian und Kirsten Heckelmann 2007 30 Genetik: Anlagen Anlage 21 The Marfan syndrome Use this family tree in your workshop to analyse how the Marfan syndrome is inherited and later to explain it to your university team! © Katrin Farian und Kirsten Heckelmann 2007 31 Genetik: Anlagen Anlage 22: Albinism: inheritance Albinism is an autosomal recessive disease. Autosomal means that men and women can have it. Most people without albinism have two correct copies of the gene that causes the disease, but only one correct gene would be enough to prevent1 albinism. People with one correct and one defective2 gene are called carriers, they have a normal pigmentation. A recessive genetic disease like albinism develops when both genes don’t work normally, so a child must inherit one copy of the defective gene from both its parents. When two carriers have a child there is a 25%-chance of it either having albinism or not having albinism and a 50%-chance of it being a carrier. 1 2 etw. verhindern fehlerhaft, defekt © Katrin Farian und Kirsten Heckelmann 2007 32 Genetik: Anlagen Anlage 23: Cystic fibrosis: inheritance CF is an autosomal recessive disease. Autosomal means that men and women can have it. Most people without CF have two correct copies of the gene that causes the disease, but only one correct gene would be enough to prevent1 CF. People with one correct and one defective2 gene are called carriers, they don’t have any symptoms. A recessive genetic disease like CF develops when both genes don’t work normally, so a child must inherit one copy of the defective gene from both its parents. When two carriers have a child there is a 25%-chance of it either having CF or not having CF and a 50%-chance of it being a carrier. 1 2 etw. verhindern fehlerhaft, defekt © Katrin Farian und Kirsten Heckelmann 2007 33 Genetik: Anlagen Anlage 24: Haemophilia: inheritance Haemophilia is a recessive disease but the mutation1 is located on the x chromosome. Most people without haemophilia have two correct copies of the gene that causes the disease, but only one correct gene would be enough to prevent2 haemophilia. People with one correct and one defective3 gene are called carriers. In this case it means that only males inherit the disease while females can be carriers of the disease and can pass on the affected gene to their children. Since a child inherits a sex chromosome each from its parents the likelihood4 to be affected by the disease varies: If the mother carries the haemophilia gene and the father is not affected, there is a 50:50 chance of a baby boy having haemophilia depending on which x chromosome he will inherit from his mother. For a baby girl it means she will have a 50:50 chance of being a carrier. If the mother is not a carrier but the father has haemophilia a baby girl will be a carrier because she automatically inherits her father’s x chromosome whereas a baby boy will not be affected by the condition and cannot pass on haemophilia in the future. A mutation is a change in the genetic information, they can be caused by mistakes in the DNA copying, by environmental factors or when the chromosomes are not distributed properly. Mutations can cause harm or give an advantage to an organism. 2 etw. verhindern 3 fehlerhaft, defekt 4 Wahrscheinlichkeit 1 © Katrin Farian und Kirsten Heckelmann 2007 34 Genetik: Anlagen Anlage 25: The Marfan syndrome: inheritance The Marfan syndrome is an autosomal dominant disease. Autosomal means that men and women can have it. Everyone has two copies of the same gene. With a dominant disease this means that only one affected gene, in our case the mutation1 for the Marfan syndrome, will cause the disease. So if one parent has Marfan any child has a 50:50 chance of inheriting the disease. For two thirds to three quarters of sufferers this is the case. This means that one quarter to one third of people had two unaffected parents. In this case a new mutation in the egg or sperm cell has taken place and causes the child to develop the Marfan syndrome. 1 A mutation is a change in the genetic information, they can be caused by mistakes in the DNA copying, by environmental factors or when the chromosomes are not distributed properly. Mutations can cause harm or give an advantage to an organism. © Katrin Farian und Kirsten Heckelmann 2007 35 Genetik: Anlagen Anlage 26: Definitionen genotype phenotype homozygous heterozygous allele dominant recessive mutation © Katrin Farian und Kirsten Heckelmann 2007 describes the genes you have describes your outward appearance (=looks) “pure” e.g. BB or bb “mixed” or hybrid e.g.Bb (two) different forms of the same gene. E.g. black “form” and white “form” for the fur colour gene. The dominant allele will determine the characteristic you can see in the phenotype. The recessive allele does not usually influence what the organism will look like because it is “dominated” by the dominant allele A mutation is a change in the genetic information, they can be caused by mistakes in the DNA copying, by environmental factors or when the chromosomes are not distributed properly. Mutations can cause harm or give an advantage to an organism. 36
