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Genetics and Species Survival

Genetics and Species Survival. What makes you, you?. Genetics and Species Survival. Our starting point is sex. Does everything have sex? Classify the organisms – have sex, don’t have sex, unsure. Feed back to the class and debate. Genetics and Species Survival. Definitions

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Genetics and Species Survival

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  1. Genetics and Species Survival What makes you, you?

  2. Genetics and Species Survival • Our starting point is sex. • Does everything have sex? • Classify the organisms – have sex, don’t have sex, unsure. • Feed back to the class and debate.

  3. Genetics and Species Survival • Definitions • Sexual reproduction (making offspring by sex) – 2 parents • Asexual reproduction (making off spring but no sex) – 1 parent. • Most large living things reproduce sexually.

  4. Sometimes you fall for the wrong partner Sometimes the girl of your dreams wants to eat your head. Sometimes it’s the last thing you do. You have to get dressed up to attract a mate (eofdreams.com) Concentrating on sex means you forget about surrounding dangers Friendships suffer Genetics and Species Survival • Why have sex? It’s not issue free …. You have to learn all the right moves

  5. Genetics and Species Survival • Sex must be very valuable for so many things to do it when there are so many dangers. • So what is sex? Write a definition of sex based on our discussion.

  6. Genetics and Species Survival • Before we can continue on to discuss why the living world bothers with sex we need to see what the alternative is. • Well the cells in your body are reproducing all the time without having sex. • See mitosis app.

  7. Genetics and Species Survival • Reproduction without sex is quite popular really • It is called asexual reproduction.

  8. Genetics and Species Survival • Asexual reproduction produces offspring that for the most part are identical to the parent.

  9. Genetics and Species Survival • The information that goes to make the off spring in asexual reproduction comes from the one parent so we get more or less exact copies. • The information that goes to make the offspring in sexual reproduction comes from two parents no exact copies. • What carries this information and where is it?

  10. Genetics and Species Survival. • Familiarisation with cells – a bit of microscope work. • Reminder about how to use • Reminder how to make a stained slide • Examine slides of cells. Record images to pass on to whole class. Might need to look at this

  11. Genetics and Species Survival www.yalemedicalgroup.org

  12. Genetics and Species Survival ohyeahdevelopmentalbiology.tumblr.com

  13. Genetics and Species Survival • In the 1950s it was discovered that the chromosomes were made of a chemical called DNA and that it had a double Helix Structure. • Practical Investigation: - Extracting DNA. • It’s really easy, especially if you have a lot of material to work with.

  14. Genetics and Species Survival So the chromosomes and the DNA they are made from seem to be the message carrier. What sort of messages to they carry? Investigation: How different are you from the other members of the class?

  15. Genetics and Species Survival • Discussion: What did the exercise with the cards tell you about your similarity to others? • How many selections on average did it take to arrive at an individual? • This activity involved phenotypes – rather than directly looking at your genes it looked at the effects your genes had on you and your behaviour. • Definition: Write a definition of phenotype.

  16. Genetics and Species Survival • Investigation: Following phenotypes through a family. • Aim: To see how genetic traits (phenotypes) have passed through a family and see if it assists in mapping genotypes (we don’t know that term yet …)

  17. Genetics and Species Survival • Equipment: • Large sheet of paper, coloured pencils. • Procedure: • Choose one of the characteristics from the card. (preferably one that was positive for you) • Draw up a blank family tree for your family (yes include anyone who shares a parent with you, aunts and uncles, and grandparents.) • At home check with family members if your tree is okay and which members of that tree have the characteristic.

  18. Genetics and Species Survival • Okay break in the investigation as you have to follow up with your families … seriously grandparents don’t mind a phone call from their grandchildren even if it is for a school assignment.

  19. Genetics and Species Survival • Inheriting genes through sexual reproduction. Some mechanisms. • Later we’ll look at how chromosomes carry these messages about you but now we’re going to look at how you inherit them. • Note: There are lots of methods and often your traits are formed from a combination of genes in complex ways – we’re going to look at simple ways.

  20. Genetics and Species Survival • Blue eyes and non-blue eyes. mrbarlow.wordpress.com Even eye colour can get complex – we’re keeping it simple.

  21. Genetics and Species Survival • First another divergence into sex. • The two sex cells are created in a similar way to new cells (mitosis) but each sex cell only receives one of each pair of chromosomes (meiosis) rather than both Only half the chromosomes. Poor things

  22. Genetics and Species Survival • Which of any pair they receive is determined by pure chance. • So when an egg is fertilized by a sperm it will have two of each chromosome – one from each parent. • Which chromosome it gets is down to chance. • There’s a more involved activity about this coming up.

  23. Genetics and Species Survival • You receive two genes for eye colour – one from each parent. • The gene can either be for blue eyes (b) or non-blue eyes (B) • There are four possible combinations in all – bb – Bb – bB – BB • As you can see two of the combinations are the same. • But it depends on which combination the parent has.

  24. Genetics and Species Survival • The genes for blue eyes (b) are recessive. • This just means that if one gene is b and the other is B the blue eyed gene loses and the eyes aren’t blue. • Let’s see some scenarios.

  25. Parent with blue eyes Parent with Brown eyes b b B Bb Bb Bb Bb B Genetics and Species Survival

  26. Parent with blue eyes b b Parent with Brown eyes B Bb Bb b bb bb Genetics and Species Survival

  27. Brown eye parent b B Brown eye parent BB B Bb Bb b bb Genetics and Species Survival

  28. Genetics and Species Survival • Here’s your turn to see if you can use these methods to make predictions.

  29. Genetics and Species Survival • Intermediate inheritance. • Sometimes two genes combine to give something in between • E.g. curly hair and straight hair giving wavy hair. • This can become very complex especially if more than one gene plays a part. • All in all – lots of chance for variety.

  30. Genetics and Species Survival • Creating model DNA • Here are the three different methods • Method 1 • Method 2 • Method 3 • Lucky dip to see which one your group gets • There are lots more options on the web.

  31. Genetics and Species Survival • The bases on the DNA chain code for a particular amino acid (these make proteins). • So for each of the bases a particular amino acid is put in place. The chain of the amino acids makes a protein. • Some bits of the DNA chain mean start and other bits mean stop – important instructions when making a protein.

  32. Genetics and Species Survival

  33. Genetics and Species Survival • It’s time we reproduced. • Not quite what I meant • Meet the parents • Here are the body parts (phenotypes) 1 2 • Here are the genotypes Male and Female

  34. Genetics and Species Survival • Breeding and Genetics Investigation: • Select the tokens for the genotypes for each parent (two tokens for each trait – Female/Male, heavy/dainty feet, muscle/tentacle arms, angry/vacant eyes) • Each parent should have two tokens for each trait. • Randomly select a token from each parent for each trait.

  35. Genetics and Species Survival • Write out the genotype for the offspring • Example • Eyes Cc, Legs SS, Arms tt, and Sex XY • Create your child … (you might need help so ask) • A few years have passed and your child has matured. Repeat the above steps but choose someone else in the class with whom to reproduce.

  36. Genetics and Species Survival • Create an extended family tree for the creatures. • What does the family tree tell us about inheritance in dominant and recessive situations?

  37. Genetics and Species Survival • Following disease through a family tree activity.

  38. Genetics and Species Survival • Genetic Engineering • Introductory video/ New Scientist Article • Brief Research Activity – to gain some background and ideas • Class discussion – how do changes in genotype affect phenotype • Give examples from research • Suggest and discuss possibilities • Ethical statement about Genetic Engineering

  39. Genetics and Species Survival • How should genetic information be used by society • Viewing Gattaca • Response (whatever form works for you) • How possible? • Benefit/Harm • Ethical considerations • Your personal position.

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