1. Welcome to a new scientific journey
Welcome to a new scientific journey. Today you will be learning about genetics and why people look the way they do.
Pretend you are a scientists, answer all questions to the best of your ability…. If you don’t know, take a guess! Remember scientists don’t KNOW all the answers, they simply SEARCH for all the answers!
Important guidelines: USE PENCIL, and once you click NEXT, you can never go back…. So make sure you read each slide carefully!!
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2. Please answer the following question on your handout: #1 How do people get some looks from their mom and some from their dad?
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3. Consider the following imaginary situation
MOM Dad
Has a straight hairline has a “Widows Peak” hairline
#2 Mom has the “straight hairline” gene dad has the “widow’s peak” gene. What kind of hairline will their kids have?
Straight
Widow’s Peak

4. You chose that their kids will have a straight hairline
You chose that their kids will have a straight hairline. Answer why in your handout Question #3
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5. You chose that their kids will have a widow’s peak
You chose that their kids will have a widow’s peak. Answer why in your handout Question #3
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6. Now pretend that Rihanna and Zinedine the soccer player really DID get married and have a baby.
And look at that, He has a straight hairline!
How does that change your answer to #3a?
Put your revised answer in #3b
Consider this: You have a friend that has a Widow’s Peak but doesn’t want their child to have a Widow’s Peak. They intend to marry someone with a straight hairline to prevent their kids form having a widow’s peak.
Will this work? Explain to them why or why not for #4 in your answer sheet.
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7. Now pretend that Rihanna and Zinedine the soccer player really DID get married and have a baby.
And look at that, they had a baby with a straight hairline!
How does that change your answer for question #3?
Consider this: You have a friend that has a straight hairline but doesn’t want their child to have a straight hairline. They intend to marry someone with a Widow’s Peak to prevent their kids from having a straight hairline.
Will this work? Explain to them why or why not for #4 in your answer sheet.
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8. So, you probably have figured out that you get a copy of genetic information from EACH of your parents.
What are those copies called?
Come up with a name for it for answer #5a
(just make something up!)
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9. Each of YOUR parents have TWO copies of every gene.
Mom Dad
Each of YOUR parents have TWO copies of every gene.
Just like you came up with a word to define what these copies are called, scientists have already come up with a name for it!
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10. Scientists named these copies “Alleles”
Scientists named these copies “Alleles”. Put that new word into #5b in your answer sheet.
Mom Dad
Alleles!
You have TWO alleles for EVERY trait you have.
Lets pretend those alleles are on the Hair Color gene.
Looks like both parents have two copies of the allele for BLONDE HAIR
This means that their children can only have BLONDE HAIR.
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11. What if mom has 2 copies of the BLONDE allele, and Dad has 2 copies of the BROWN allele?
Mom Dad If their child will get one copy from EACH parent, what alleles will the child have?
FOUR Allele choices! A: B: C: D: E:

12. Choice A is incorrect, remember that the child needs a copy from EACH parent… don’t forget about DAD.
Return to the question

13. Choice B is incorrect, remember every person has TWO copies of every gene….
Return to the question

14. Answer C is incorrect, remember every person gets a copy from EACH parent… don’t forget about MOM
Return to the question

15. The child will have a BROWN and BLONDE allele
Answer D is CORRECT!
The child will have a BROWN and BLONDE allele
So, we know what their GENES are, but how do we know how their hair will APPEAR?
As you can see, alleles have TWO parts of information: they make up the GENES inside us, and those genes tell our bodies how to APPEAR.
Describe this in your own words for question #6a
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16. Answer E is incorrect, remember every child gets TWO copies of an allele
Return to the question

17. Back to the question, what will a person’s hair color be if they carry BOTH the brown allele AND the blonde allele?
Make a guess!
Blonde
Brown

18. You guessed BLONDE
If someone has both brown and blonde alleles, explain why you said blonde for question #7
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19. You guessed BROWN
If someone has both brown and blonde alleles, explain why you said brown in question #7
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20. This power is called dominance
In your explanation for #7 you might have said that certain alleles have more power over other alleles.
This power is called dominance
Some alleles are dominant over recessive alleles
Now, restate your answer to #7 using the words recessive and dominant for question #8
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21. Now, lets return to the TWO parts of information that alleles provide.
The two alleles consist of the GENE.
This GENE controls the APPEARANCE of the person.
Scientists have come up with two words to describe this, called GENOTYPES and PHENOTYPES. Put his in your answer to #6b matching it with the definition you already have.
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22. Back to the hair color Example
We know that the child has a BROWN allele and a BLONDE allele This is their GENOTYPE If BLONDE is recessive to BROWN what will the PHENOTYPE of this person be? A: Brown B: Blonde C: I don’t know

23. A is correct! The person will have BROWN hair because the dominant allele will be the one shown in the PHENOTYPE Put your answer to this question for #9
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24. B is not correct, remember, if the blonde allele is recessive to Brown, then brown is dominant over blonde
Return to the question

25. Yes you do!!
Return to the question

26. Ok, now for a little practice
Hitchhiker's thumb
Hold out your hand and make a fist with the thumb extended. Bend the last joint of the thumb back as far as possible. A straight thumb is dominant while a bent thumb is recessive.
Lets call the non-bending allele 1
Lets call the bending allele 2
(write that for #10)
If a man with the GENOTYPE 1, 1
marries a woman with the GENOTYPE 2, 2
what will the GENOTYPE of their child be?
A: 1, B: 1, C: 2, D: Straight Thumb E: Bent Thumb

27. Answer A is incorrect
1, 1 means that they got a 1 from their mom and their dad….. Is that correct?
Return to the question

28. B is correct!!
Lets draw it out in something called a Punnett square. Copy this into #10 using different colors as shown! 2
1, 2
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29. Answer C is incorrect
2, 2 means that they got a 2 from their mom and their dad….. Is that correct?
Return to the question

30. Answer D is incorrect
Remember, this question is asking for GENOTYPE, not PHENOTYPE
Return to the Question

31. Answer E is incorrect
Remember, this question is asking for GENOTYPE not PHENOTYPE
Return to the question

32. Complete the Punnett Square in question #11
NOW suppose that their child, with genotype 1, 2 grew up and married a woman with a genotype of 2, 2
Complete the Punnett Square in question #11
Mom’s Alleles
Possible genotype #1
Possible Genotype #2
Possible Genotype #3
Possible Genotype #4
Make a Punnett square and put the correct alleles in the boxes using the example from #10
Dad’s Alleles
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33. What did you put in this box?
C: 1
D: 1, 2

34. Answer A is incorrect, there should only be one allele for each column
Return to the question

35. Answer B is correct!
The mother has TWO alleles of type 2…. So one goes on the top of each column
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36. Answer C is incorrect, remember, the child marries a woman with genotype 2, 2
Return to the question

37. Answer D is incorrect remember, only one allele goes in each column
Return to the question

38. More practice Can you roll your tongue into a flower??
Show your partner and fill in question #12
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39. The tongue rolling gene will be designated by the number 1
The non-tongue rolling gene will be designated by the number 2
Put these facts down in question #13, you will need them later
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40. # 14 If a man with genotype 1,2 marries a woman with genotype 1, 2 make a Punnett square showing the possible offspring genotypes.
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41. Looking at the possible offspring genotypes, there should be two squares with the same genotype… what is that genotype?
A: 1, B: 1, 2 C: 2, 2

42. A is incorrect, there should not be two boxes with 1, 1 in them.
Return to question

43. Your Punnett square should look like this
Answer B is correct!!
Your Punnett square should look like this 1 2
1, 1
1, 2
2, 2 1 2
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44. Answer C is incorrect, you should not have two boxes with the genotype 2, 2
Return to the question

45. Genotype Phenotype (tongue rollers, or not tongue rollers?) 1, 1 _____
Ok so if the tongue rolling gene (1) is dominant over the non-tongue rolling gene (2) then predict if these people will be able to roll their tongue. Copy this down for answer #15
Genotype Phenotype (tongue rollers, or not tongue rollers?)
1, _____
1, _____
2, _____
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46. Ok, so if people with the genotype 1, 1 AND
1, 2 can roll their tongue… look at your Punnett square carefully and make an educated guess of the percent chance that this couple will have a child that CAN roll their tongue.
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47. So maybe you figured it out, but maybe you didn’t… its okay, it took scientists hundreds of years to figure this out!
A man named Gregor Mendel did hundreds of experiments in the 1840’s and people didn’t even think they were important until the mid 1900’s!!
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48. Ok so back to the question. Let’s remember your Punnett Square
# 17 Out of the four
Squares, how many
Show the trait of
Tongue rolling?
____ out of four
What percentage is that?
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49. You might see where I am going with this…..
#17 continued
Out of four, how many cannot roll their tongue?
What percentage is that?
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50. A new idea
Sometimes people have two of the same allele for example 1, 1 or 2, 2
Sometimes they are different, for example 1, 2
Come up with a name for each of these cases for question #18 (yes I want you to just make something up!)
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51. Let’s use this new information to help Bella make a tough decision.
Bella is still trying to decide who to marry, Edward or Jacob.
Besides deciding between a warewolf or a vampire, Bella is really concerned about having a child with a dimple in it’s chin.
# 19 (write this down) The chin dimple allele is dominant. We will call that allele 1
The non-dimpled chin is recessive.
We will call that allele 2
If Bella doesn’t have a chin dimple, what must her genotype be?
A: Chin Dimple B: 1, C: No Chin dimple
D: 1, 2 E: 2, 2

52. A is incorrect, a physical trait is a PHENOTYPE not a GENOTYPE!
Return to the question

53. B is incorrect, remember the 1 allele is the chin dimple allele.
Return to the question

54. C is incorrect, a physical trait is a PHENOTYPE not a GENOTYPE
Return to the question

55. D is incorrect, if 1 is dominant over 2, then if 1 was present, wouldn’t Bella have a dimpled chin? But she doesn’t… so try again!
Return to the question

56. Her genotype is 2, 2 (mark that in #19)
E is correct!!
Bella MUST have two of the recessive alleles in order for the recessive phenotype to show.
Her genotype is 2, 2 (mark that in #19)
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57. Edward vs Jacob
Bella wants her kids to have a dimpled chin, she thinks it’s SO cute,
Who should she choose?
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58. UH OH! The baby doesn’t have a chin dimple…. What happened?
There is a genetic explanation for this!
#20 Draw a Punnett square using Bella’s Alleles and Jacob’s Alleles to show how this may have happened
Bella’s Alleles here
Jacob’s
Alleles
here
Hint: Keep trying Punnett squares until you find the answer!!
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59. # 21 Now I would like you to write an explanation of how Bella and Jacob had a baby without a dimpled chin. Here are some words to include in your explanation. Fill these in on your worksheet Heterozygous= when a person carries two DIFFERENT alleles (example 1, 2) Homozygous= when a person carries two of the same alleles (example 1, 1) Carrier= When a person SHOWS the dominant PHENOTYPE (like a chin dimple), but carries the recessive allele.
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60. Using your Punnett square from #21, predict the percent chance that Bella and Jacob’s next baby will have a dimpled chin.
A: 25 % B: 30% C: 75% D: 50% E: 0%
I love you Bella!
I’m just so
confused!!

61. Answer A is incorrect
25% would suggest that only 1 out of four boxes contain a genotype that would give a dimpled chin…. Look again!
Return to the question

62. Answer B is incorrect
In the type of genetics we are studying, there can never be a 30% chance of a certain phenotype.
Return to the question

63. Answer C is incorrect, 75% would suggest that 3 out of the 4 boxes carry the allele 1 for chin dimples.
Return to the question

64. Answer D is correct!!! 1
1, 2 1, 2
2, 2 2, 2 2
These two boxes represent the two possibilities of a child having no dimple in its chin. Therefore there is a 2 out of 4 chance that the child will not have a dimple… 50%!!!!
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65. Answer E is incorrect, 0% would suggest that there are no boxes that carry the 1 allele for chin dimples… that can’t be right if Jacob has a 1 allele and could give it to his children!
Return to the question

66. WOW You have learned SO MUCH!! Lets summarize:
Define these 8 ideas in your OWN words: Recessive, Dominant, Homozygous, Heterozygous, Allele, Carrier, Genotype, Phenotype. And write down what a Punnett square is used for.
I’m done with the Idea Summary and
Am ready to continue to the extra credit video.

67. Here is a cool video showing how birds “advertise” good genes
Here is a cool video showing how birds “advertise” good genes. All mating behavior is designed to say “hey look at me… my genetics are great, be my mate!!”
Click on the video only if you have headphones!