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B1-L1, How do we vary? LO: What makes us all different? What are genes and what do they do? Look at the person next to you. Name 5 things that are different.

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Presentation on theme: "B1-L1, How do we vary? LO: What makes us all different? What are genes and what do they do? Look at the person next to you. Name 5 things that are different."— Presentation transcript:

1 B1-L1, How do we vary? LO: What makes us all different? What are genes and what do they do? Look at the person next to you. Name 5 things that are different about you Now sort them into two boxes Things we got or inherited from our parents Things that happened as we grew up or are changed by the environment

2 Inherited or environmental variation?

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12 OK: so how do you Inherit features? See if you can explain the following facts: 1.50% of what makes ‘you’ comes from your dad 2.There is 50% chance of a child being male or female 3.A child with one brown haired parent is more likely to have brown hair than blond 4.We may be able to choose what our children look like in the future.

13 People are all very similar but still unique. How does this happen?

14 All the information to make this baby came from his parents.

15 Information from each parent is carried in their sex cells.

16 All the information to develop a human being has to fit inside the nucleus of a fertilized egg cell.

17 There are about pieces of information in the nucleus. Each piece of information is called a gene. And it tells the body how to make proteins Genes are joined up in chains called chromosomes. Each chromosome in the nucleus contains thousands of genes. Copy me:

18 Inside a cell

19 These are all the chromosomes from one human cell. 99.9% of the information in any fertilized egg is the same. Only 0.1% of the information they carry makes this person unique.

20 Most features are controlled by several genes and are also affected by the environment, e.g. height.

21 Hair colour.

22 True of False Chromosomes are found in the nucleus. Sperm and egg cells have the same amount of information as other body cells. When we are adults our cells stop dividing. Everyone in this room in unique. Genes are joined up into chains called chromosomes. The environment we grow up in causes variation. Our genetic information causes variation. Only the environment and genetics causes variation.

23 1 in 25 people carry the faulty gene that causes cystic fibrosis.

24 1.Name one inherited variation you have? 2.Name one environmental variation you have? 3.What p_____ is made by the instructions on our genes? 4.Why are we different from each other? 5.Match up the following letters and words: Chromosome Gene Nucleus Each chromosome in the nucleus contains thousands of genes. A B C B1-L2, How do we vary? LO: To know how sex cells are made and the numbers of chromosomes involved.

25 Sometimes genes are faulty. How many people in this photograph do you think have no faulty genes?

26 None? We all have some faulty genes.

27 A small number of faulty genes cause diseases. This person has cystic fibrosis.

28 Cystic fibrosis is the most common inherited disease in the UK. It affects 1 in every 2500 people.

29 Growth vs. Gametes Mitosis – Growth (asexual reproduction) Meiosis – Gametes (sex cells)

30 50% of what makes ‘you’ comes from each parent 23 pairs = 46 chromosomes In a woman each pair splits giving an egg cell In an man each pair splits giving a sperm cell

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32 Male body cell 46 Chromosomes Female body cell 46 Chromosomes Egg cell 23 Chromosomes Sperm cell 23 Chromosomes Baby cell 46 Chromosomes 50% Mum and 50% Dad

33 It’s true, Boys do have a little ‘y’ chromosome.

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35 Practice Exam Questions For your progress folders EXAM CONDITIONS

36 1.chromosomes in a human body cell 2.pair of chromosomes which controls what sex a person is 3.pair of sex chromosomes a woman has 4.pair of sex chromosomes a man has 5.chromosomes in a egg or sperm cell B1-L3, Dominant and recessive LO: To know how pairs of genes control features XY 23 rd XX

37 ALLELES Dominant and Recessive

38 Dragons Help! Only two dragons in the world are left. What might their children be like?? These things all depend on the combination of genes - alleles Breaths fire? How many toes? Tail spikes? Colour?

39 q Q q Q e E e E D d D d L l L l A a A a M m M m t T t T Blue are daddy dragon genes and Yellow are mummy dragon genes.

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41 Plenary – write a definition for these words Chromosome Gene Alleles Dominant Reccesive Genotype Phenotype

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43 B1-L4, Punnett squares and Variation LO: To know how pairs of genes control features BB = Brown eyes and B is dominant bb = Blue eyes Complete these squares to show all the combinations of alleles MUM = Brown eyes B B Dad = Blue eyes bbbb MUM = Brown eyes B b Dad = Brown eyes BbBb

44 Eye colour In eye colour the brown eye allele is dominant, so we call it B, and the blue eye is recessive, so we call it b: bbBBBb Homozygous brown-eyed parent Heterozygous brown-eyed parent Blue-eyed parent What would the offspring have?

45 BB b b Another method Example 1: A Homozygous brown-eyed father and a blue-eyed mother: BB bBb b Father Mother All offspring have brown eyes

46 Bb B b Another method Example 2: Two heterozygous brown-eyed parents: Bb BBBb b bb Father Mother 25% chance of blue eyes

47 Bb b b Another method Example 3: A heterozygous brown-eyed father and a blue-eyed mother: Bb bBbbb bBbbb Father Mother

48 GENETIC CROSSES

49 The inheritance of dimples A person with the genes DD will have dimples. A person with the genes dd will not have dimples. A person with the genes Dd will have dimples.

50 The inheritance of dimples In a person with the genes Dd only the effect of gene D shows. The effect of gene D dominates the effect of gene d. Gene D is dominant to gene d. Gene d is recessive to gene D.

51 D is the gene for dimples d is the gene for no dimples

52 Parents DDdd Body cell in father with a pair of genes for dimples Body cell in mother with a pair of genes for no dimples

53 D is the gene for dimples d is the gene for no dimples Parents DDdd Body cell in father with a pair of genes for dimples Body cell in mother with a pair of genes for no dimples Gametes

54 D is the gene for dimples d is the gene for no dimples Parents DDdd Body cell in father with a pair of genes for dimples Body cell in mother with a pair of genes for no dimples Gametes DD each sperm has a gene for dimples

55 D is the gene for dimples d is the gene for no dimples Parents DDdd Body cell in father with a pair of genes for dimples Body cell in mother with a pair of genes for no dimples Gametes DD each sperm has a gene for dimples dd each ovum has a gene for no dimples

56 D is the gene for dimples d is the gene for no dimples Parents DDdd Body cell in father with a pair of genes for dimples Body cell in mother with a pair of genes for no dimples Gametes DD each sperm has a gene for dimples dd each ovum has a gene for no dimples At fertilization There are 4 possible ways of joining a sperm to an ovum

57 D is the gene for dimples d is the gene for no dimples Parents DDdd Body cell in father with a pair of genes for dimples Body cell in mother with a pair of genes for no dimples Gametes DD each sperm has a gene for dimples dd each ovum has a gene for no dimples At fertilization There are 4 possible ways of joining a sperm to an ovum DDDD

58 D is the gene for dimples d is the gene for no dimples Parents DDdd Body cell in father with a pair of genes for dimples Body cell in mother with a pair of genes for no dimples Gametes DD each sperm has a gene for dimples dd each ovum has a gene for no dimples At fertilization There are 4 possible ways of joining a sperm to an ovum DDDD

59 D is the gene for dimples d is the gene for no dimples Parents DDdd Body cell in father with a pair of genes for dimples Body cell in mother with a pair of genes for no dimples Gametes DD each sperm has a gene for dimples dd each ovum has a gene for no dimples At fertilization There are 4 possible ways of joining a sperm to an ovum DDDD d

60 D is the gene for dimples d is the gene for no dimples Parents DDdd Body cell in father with a pair of genes for dimples Body cell in mother with a pair of genes for no dimples Gametes DD each sperm has a gene for dimples dd each ovum has a gene for no dimples At fertilization There are 4 possible ways of joining a sperm to an ovum Dd DDDD d

61 D is the gene for dimples d is the gene for no dimples Parents DDdd Body cell in father with a pair of genes for dimples Body cell in mother with a pair of genes for no dimples Gametes DD each sperm has a gene for dimples dd each ovum has a gene for no dimples At fertilization There are 4 possible ways of joining a sperm to an ovum Dd DDDD d All the children of this generation have genotype Dd and phenotype - dimples

62 Parents Dd father with dimples mother with dimples Gametes At fertilization What would happen in this example?

63 Parents Dd father with dimples mother with dimples Gametes Dd Dd At fertilization DDDd dd DdDd D d A child who inherits the genes DD will have dimples A child who inherits the genes Dd will have dimples A child who inherits the genes dd will not have dimples In this generation the ratio of dimpled children to non-dimpled will be 3 to 1 Answer:

64 DANGLY ATTACHED

65 Continuous and Discrete variation?

66 Helpful videos – Huntingtons

67 Produce a poster about Huntingtons pg 12 Cystic fibrosis pg 16 and 17 Jan – pg 19 Rhys and SCID – pg 29

68 B1-L5, genetic diseases LO: To know how disease can be inherited True or false?? 1.Xx is female 2.BB is brown eyes 3.Bb is blue eyes 4.There are 23 chromosomes in a body cell 5.Chromosomes are part of a gene 6.Alleles are types of gene 7.Dd + Dd means a 50% chance of DD 8.Testosterone is a hormone that decides if you will be a boy

69 write a definition for these words Genotype Phenotype what are proteins used for???

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71 Genetic diseases Can anyone name a genetic disease? Trait Chromosome for Gene Location Genotype Recessive or dominant skin cancer1Cc or CC D cystic fibrosis7qq R albinism11aa R Breast cancer17Nn or NN D Muscular Dystrophy X sex chromoso me Mm or MM (girls only) D Huntingtons4Hh or HH D Down’s Syndrome Extra copy of 21

72 HUNTINGTON’S DISORDER 1.Huntingtons disease is a dominant one. 2.Do 4 genetic crosses to determine the chance of these couples having children with Huntington’s disorder: a. Hh x hhb. HH x hh c. HH x Hhd. Hh x Hh

73 CYSTIC FIBROSIS 1.Cystic fibrosis is a recessive one. 2.Do 3 genetic crosses to determine the chance of these couples having children with Cystic fibrosis: a. Ff x ffb. Ff x Ff c. FF x Ff

74 Cystic fibrosis 1 2 3

75 WS Huntington’s and Cystic fibrosis

76 Now what?? You know you both carry the recessive gene? What would you do??

77 Genetic testing It is now possible to test individuals before they are born for any faulty alleles. There are two main methods: 1) Amniocentesis testing: - Done at weeks - 0.5% chance of miscarriage (5 in 1000) - Small chance of infection

78 Genetic testing It is now possible to test individuals before they are born for any faulty alleles. There are two main methods: 2) Maternal serum screening: - Blood test of mother - 0% chance of miscarriage - Does not give precise results -High or Low risk of having a poorly baby...

79 DIFFERENT IDEAS ABOUT GENETIC SCREENING FOR CYSTIC FIBROSIS Read pages to find out what genetic screening is. Which opinion do you agree with? It is very dangerous. People should not have to worry about this information. There’s nothing wrong in having an ill child. What if my husband and I both had the faulty allele? Would we have children? I want to choose my medical treatment – not have any forced on me! We should give people all the information we can about their health. Then they can make an informed decision.

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83 For some causes of infertility, IVF provides a wonderful opportunity The financial and emotional conflicts that arise out of IVF can put huge strains on a relationship Any society where people can afford IVF will be one where overpopulation will not…

84 Exam question!

85 You can have IVF treatment to make sure your next baby doesn’t have cystic fibrosis What should we do, Doctor? Decision 1

86 How do you make an ethical decision?

87 Imagine you are one of the Simpletons. You have been asked about IVF. How will you respond?

88 My approach to ethical dilemmas: Weigh up the benefits and costs and choose the option that makes most people happy. This is the ‘utilitarian approach’

89 My approach to ethical decisions: Before I do anything, I make sure it does not violate other people’s rights. This is rights-based thinking

90 My approach to ethical decisions: Be caring and compassionate about people and relationships. This is care-based thinking

91 My approach to ethical decisions: I simply choose the option that turns out best for me. This is self-centred thinking

92 What are the problems (cons) of doing this? What are the benefits (pros) of doing this? Who is affected? Utilitarian What must I decide about? Conclusion My approach to ethical decisions: Weigh up the benefits and costs and choose the option that makes most people happy.

93 Will the decision violate (go against) any rights? How? What rights do we want to protect? (e.g. choice, freedom, life) Who is affected? Rights-based Conclusion What must I decide about? My approach to ethical decisions: Before I do anything, I make sure it does not violate other people’s rights.

94 How will doing this make their life worse? How will doing this make their life better? Who is affected? Care-based Conclusion What must I decide about? My approach to ethical decisions: Be caring and compassionate about people and relationships.

95 How important is this to me? Is this a good thing for me or a bad thing for me? Who is affected? Self-centred Conclusion What must I decide about? My approach to ethical decisions: Simply choose the option that turns out best for me.

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101 Exam question starter

102 CAN YOU CHOOSE YOUR CHILD? Define the following words: 1. embryo 2. implantation 3. in vitro fertilisation 4. pre-implantation genetic diagnosis

103 GENE THERAPY Read page : Questions 1-5 And write the definitions for the following words Gene therapy Genetic modification

104 GENE THERAPY Gene therapy – a treatment where a normal gene is put into cells of someone with a genetic disorder. Genetic modification – the changing of an organism’s genes. In gene therapy this is by the addition of normal genes.

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106 How many things could you use a clone for?

107 Asexual reproduction in cells Each daughter cell has the same number of chromosomes and genetic information as the parent.

108 Natural clones

109 How to clone A plant An animal

110 Cloning Animals Host motherClone

111 Should we try to develop cloning technology? Should we change faulty genes? (gene therapy, pre- implantation genetic diagnosis, genetic modification) How can we go about making this type of decision?

112 Stem cell research Stem cells are cells that have not yet specialised: Egg and sperm Embryo Cloned embryos These stem cells have the potential to develop into any kind of cell. The rest of the embryo is destroyed. Most of these embryos come from unused IVF treatments. The ethical issue: Should these embryos be treated as humans?

113 Making decisions Some questions cannot be answered by science and need to be considered on ethical grounds. Factors that might influence a decision: Beliefs/religion What does “the right thing” mean? “Playing God” Risks – acceptable or unacceptable? Social and economic contexts

114 Draw a cartoon to show the cloning process. include science diagrams too!

115 Fill in the G A P S Clones of ________ can occur when an embryo splits up naturally. Embryonic ________ cells are _____________ cells that can grow into any type of cell. These cells can be grown from ________ left over from ________ treatments. Embryonic stem cells may be useful in the future for treating _________. animals embryosillnesses IVFstem unspecialised

116 should we be able to clone embryos?

117 Cloning with cuttings To do Fill a small pot with compost. Cut the stem about 10 cm from the tip. Cut just below a leaf at an angle. Don’t cut straight across. Take off the leaves at the bottom of your cutting. Dip the cut end in rooting powder if you have some. Put the cutting in your compost. Push it in gently until the compost is just below the bottom leaf. Label your pot with your name and the date. Put a plastic bag loosely over your plant. In a few weeks your plants will have grown roots.

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