1. Key Area 2.4 Genetic information

2. Starter Activity: Discuss the following questions with your partner: What are genes? Where in your cells are your genes found? What chemical makes up your genes? What physical characteristics are controlled by your genes?

3. Variation Learning Intention: To learn about how genes control the physical appearance of an organism Success Criteria: Be able to define the terms chromosome, DNA, gene and variation Understand that physical characteristics are inherited from biological parents through sections of DNA

4. Family resemblance Members of the same family often look similar. Which parent do these children look more like? Humans, like all organisms, inherit characteristics from their parents. How are characteristics passed on? Why do members of the same family look similar? Characteristics pass on through reproduction.

5. Species A species is a group of organisms who can interbreed and produce offspring which are fertile (able to reproduce). All humans can interbreed so we are all the same species.

6. Some unusual examples Some animals seem to be members of the same species but are not. The animals may be able to interbreed and produce young, but the young are not able to reproduce. Two examples are mules and ligers.

7. X = A mule is infertile, so horses and donkeys are not the same species.

8. X =

9. Variation Although the members of a species are very similar to one another, they are not identical. Variation occurs among members of a species.

15. Variation Variation – differences that exist among members of a species.

16. What is variation? Differences due to inherited and environmental factors that exist between members of a species.

17. Human Variation Eye Colour Hair Type HeightTongue rolling Shoe sizeHair Colour Blood groupHandspan FingerprintsFreckles WeightHandednessHeart Rate Twig Video: Human Variation Examples of human variation include:

18. Variation Learning Intention: To learn about how genes control the physical appearance of an organism Success Criteria: Understand that physical characteristics are inherited from biological parents through sections of DNA

19. Starter

20. Variation For some characteristics there are clear groups of individuals. Tongue rolling- can or cannot Blood group – A,B,AB or O Fingerprint patterns – whorls, loops, arches Shape of leaves on oak trees – lobes, no lobes Colour of petals on a flower Seed colour in peas – green, yellow, brown

21. Variation graphs For any variation where the data gives distinct groups, a bar chart or pie chart can be used. NUMERACY

22. Human Variation You will look at examples of variation within the class and construct a table.

23. Activity 1 Complete the table in your booklet identifying the characteristics of people in the class. Name Ear lobes attached yes/no Freckles yes/no Tongue roll yes/no Left/right handed

24. Name Ear lobes attached yes/no Freckles yes/no Tongue roll yes/no Left/right handed Choose two of these variations, and draw a bar chart for each.

25. Measured variation For some characteristics there are not clear groups of individuals. Instead there is a broad range of measured values. Height of rowan trees Weight of rabbits Pulse rate in humans Leaf size in geraniums Weight of chestnuts from tree Height in humans

26. Range of heights and sizes

27. Variation graphs In this type of measured variation, most individuals have heights in the centre of the range, with few at the extremes. This type of graph is called a histogram or frequency graph. NUMERACY

28. Activity 2 Complete the table in your booklet showing the hand spans of people in the class. Then complete the summary table and histogram. Hand span (cm)Number of peopleTotal number of people Less than 17.5 17.5 18 18.5 19 19.5 20 20.5 21 21.5 22 or over

29. Hand span (cm)Number of people (tally mark) Total number of people Less than 17.5 17.5 18 18.5 19 19.5 20 20.5 21 21.5 22 or over

30. Structure of DNA and Genes

31. Genetic information Learning Intention: To learn about how genes control the physical appearance of an organism Success Criteria: Be able to define the terms chromosome, DNA, gene and variation Understand that physical characteristics are inherited from biological parents through sections of DNA

32. What is DNA? DNA stands for Deoxyribonucleic Acid. DNA is found in the nucleus of a cell. It is would up very tightly into structures called chromosomes.

33. Chromosomes A chromosome is a threadlike structure that carries genetic information.

35. Gene

36. Genes Chromosomes are split up into smaller segments called genes. A gene is a section of a chromosome that contains a piece of genetic information e.g. the gene for tongue rolling. We inherit half of our genes from our mother and half from our father. This means that two genes control each characteristic.

37. How are genes inherited?

38. The parents Homer has straight hair Marge has curly hair

39. The families Is hair curliness controlled by genes or by the environment?

40. Homer Homer has straight hair. Every cell in Homer has two sets of genes. Homer’s has two straight hair genes. We can show the straight hair gene with a capital H. Homer’s genes: HH.

41. Marge Marge has curly hair. Every cell in Marge has two sets of genes. Marge has two curly hair genes. We can show the straight hair gene with a small h. Marge’s genes: hh

42. Making a new Simpson Homer makes sperm. Each sperm has one gene for hair type. Homer only has straight hair genes. So all of his sperm have straight hair genes. Homer’s Sperm HH

43. Making a new Simpson Marge makes eggs. Each egg has one gene for hair type. Marge only has curly hair genes. So all of her eggs have curly hair genes. Marge’s Eggs hh

44. Making a new Simpson h h H H Hh This type of diagram is called a punnet square.

45. Making a new Simpson Hh All of the Simpson babies have one gene for curly hair and one gene for straight hair So what type of hair do they have?

46. Making a new Simpson Hh THEY ALL HAVE STRAIGHT HAIR! The straight hair gene is DOMINANT. Just one copy of this gene will give you that characteristic. The curly hair gene is RECESSIVE. You need two copies of the gene to have that characteristic.

47. Liking donuts Homer likes donuts Every cell in his body has two donut liking genes. His genes are: D D Homer’s sperm D D

48. Liking donuts Marge doesn’t like donuts. Every cell in her body has two donut disliking genes Her genes are: d d Marge’s Eggs d d

49. Making a new Simpson d d D D Dd

50. Making a new Simpson Dd Liking donuts is dominant Do the Simpson children like donuts?

51. Weight Marge has normal weight. Both of her weight genes are for normal weight. Her genes are: N N If you have two identical genes, this is known as true breeding. Marge is true breeding for normal weight. Marge’s Eggs N N

52. Weight Homer does not have normal weight. He is overweight. Homer is true breeding for being overweight. This means both of his weight genes are for being overweight. His genes are: n n Homer’s sperm nn

53. Making a new Simpson Nn Normal weight is dominant. What weight do all the Simpson children have – normal or overweight?

54. Activity 3 – Homer and Marge Cross NumberHomer’s characteristic Homer’s genesMarge’s characteristic Marge’s genes 1Likes beerBBDoesn’t like beerbb 2Plays sportsSSDoesn’t play sportsss 3BurpsBBDoesn’t burpbb 4LazyLLNot lazyll For each of the above characteristics, work out what their children are likely to be like.

55. The next generation? Lisa has straight hair. Every cell in Lisa has two sets of genes. Lisa has one gene for straight hair (H), which is dominant. She also has one gene for curly hair (h), which is recessive. Lisa is not true breeding. Lisa’s genes: Hh

56. Milhouse has straight hair. Every cell in Milhouse has two sets of genes. Milhouse has one gene for straight hair, which is dominant. He also has one gene for curly hair, which is recessive, so he is not true breeding. Milhouse’s genes: Hh

57. Milhouse’s genes: Hh Milhouse’s sperm: Hh Hh Lisa’s genes: Hh Lisa’s eggs:

58. The next generation? What if Lisa and Milhouse have children? H h h H HH hh Hh

59. The next generation HHhhHh Straight hair is dominant. Imagine Lisa and Milhouse have 4 children. How many children will have straight hair? How many will have curly hair?

60. Activity 4 -The next generation Cross NumberLisa’s characteristic Lisa’s genesMilhouse’s characteristic Milhouse’s genes 1Likes SchoolSsLike SchoolSs 2Good eyesightEEBad eyesightee 3BraveBbNot bravebb For each of the above characteristics, work out what their children are likely to be like using the punnet squares in your worksheet. If you feel confident, you can try the extension exercise in the booklet.

61. Variation We can see that not all of Lisa and Milhouse’s children would be the same. This is because each child inherits a slightly different set of genes from their parents. This creates variation within families, and variation within the population.

62. Starter

63. Say hello……to the Reebops

64. Activity 5 – Making Reebops 1.Open each envelope, take out the cards and sort them out into Mum’s (pink) and Dad’s (blue). 2.Sort each set of chromosomes into pairs of the same length. Now turn all the chromosomes over. 3.Randomly take one chromosome from each pair of Mum’s chromosomes and place in a pile called ‘female gamete’. 4.Randomly take one chromosome from each pair of Dad’s chromosomes and place in a pile called ‘male gamete’. 5.Put the unpicked chromosomes back in the envelope.

65. Fertilisation 1.Mix the two sets of chromosomes together. This is what happens in fertilisation. 2.Sort out the chromosomes into size again. 3.Use the decoder key to decide what characteristics your Reebop has. Write these in the table in your booklet. 4.Now you can make your Reebop!

66. CharacteristicDecoder antennaeAA = 2 antennaeAa = 2 antennaeaa = no antennae body segments BB = 3 body segments Bb = 3 body segments bb = 2 body segments tailTT = curly tailTt = curly tailtt = straight tail noseNN = red noseNn = orange nosenn = yellow nose legsLL = blue legsLl = blue legsll = red legs sex XX = female (pink body) XY = male (non pink body) eyesEE = 2 eyesEe = 2 eyesee = one eye humpsHH = 1 humpHh = 1 humphh = 3 humps Decoder key

68. Questions 1.Are there any baby Reebops that are identical? 2.How much genetic material does each parent provide? 3.How is this genetic material passed on to the children? 4.Why is there variation in families?