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Explore the fascinating world of genetics through engaging tales and clear explanations. This presentation covers key concepts such as dominant and recessive characteristics, genotype and phenotype, and inheritance patterns in young fish observed by Esther. Discover how gene pairs from both parents influence traits, the use of Punnett squares in predicting characteristics, and learn about human blood types. Join us in understanding how genes shape the diversity of life and the intricacies of inheritance.
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Genetics Here is the Gene family. Mr and Mrs Gene are in the centre. And here are their three children.
Genes • Only one characteristic will be expressed, or seen, in the individual. • This gene is said to be dominant. • The characteristic that is not seen is said to be recessive. Complete 4
A Fishy Tale • One day, Esther came home from a concert and noticed 8 new baby fish. • She also observed that 2 of them were black and 6 were red. • “How could this happen?” Esther puzzled. “Both parents were red”.
Young’s genes Father’s genes Mother’s genes Mum to the Rescue • Esther's Mum explained a bit more about how genes worked. • She suggested that each young fish had two similar genes controlling their colour. One passed down from the mother and one from the father.
r r R R R R Young’s alleles Father’s alleles Mother’s alleles Mum to the Rescue Possibility 1 Genotype RR Phenotype Red scales
r r r R R R Young’s alleles Father’s alleles Mother’s alleles Mum to the Rescue Possibility 2 Genotype Rr Phenotype Red scales
r r r R R R Young’s alleles Father’s alleles Mother’s alleles Mum to the Rescue Possibility 3 Genotype Rr Phenotype Red scales
r r r r R R Young’s alleles Father’s alleles Mother’s alleles Mum to the Rescue Possibility 4 Genotype rr Phenotype Black scales
Possibility 1 Parent 1 Possibility 3 R r Parent 2 R RR Rr r Rr rr Possibility 4 Possibility 2 Mum to the Rescue • We can show all these possibilities in a diagram called a Punnet square …
1 2 3 4 5 6 7 8 9 10 11 12 Hooked Nose Female Male No Hooked Nose Hooked Noses • If H = hooked nose and h = normal nose, what is the genotype of individual 9? • What is the genotype of individual 5? Complete ‘Hooked Noses’
Parent 1 B b Parent 2 Bb Bb Bb Punnet Squares • This punnet square was to be used to predict the eye colour of a child of Parents 1 and 2. • Unfortunately, it has been damaged. • The gene for brown eyes, B, is dominant over the gene for blue eyes, b.
Human Blood Types • There are four main blood types in humans: A, B, AB and O. • There are 3 genes which carry blood type: A, B and O. • A person carries 2 of the 3 genes.
Cloning in Nature 1. How is this type of breeding similar to cloning? How is it different to cloning? 2. “Armadillos are taking a risk in producing identical offspring”. Why might the armadillos be at risk from this type of reproduction? Worksheet
PowerPoint presentation by Jo Kennedy Graphics & Design by Esther Kennedy Thanks to the students for the use of their photos • ORB Education Visit http://www.orbeducation.com for a range of quality teaching materials.
