1. 9-1 How come you look like you?
It’s in your genes!

2. Transmission of characteristics from parents to offspring is called ___________________.
The STUDY of how those characteristics are passed on from one generation to the next is called
___________________
heredity
Genetics

3. Gregor Mendel The Father of Genetics is _________________,
The Father of Genetics is _________________,
a monk whose study of genetic traits was the beginning of our understanding about how genes work.
Gregor Mendel

4. Mendel designed experiments using _________________________.
He looked at different observable CHARACTERISTICS or ______________
Pea plants
TRAITS

5. Pea Characteristics

6. A plant that ALWAYS produces offspring with a certain trait are called ___________ for that trait.
PURE

7. Remember all body cells have 2 copies of every gene, so to breed pure the 2 parent gene choices must be the_________.
SAME
red flower alleles
TWO

8. PURE white
flowered plants
have ______
WHITE flower alleles
TWO

9. Mendel combined genes from 2
PURE parent plants and recorded the kinds of ___________ produced.
In his experiments the 1st plants crossed were called the ____
generation. ( P is for parental)
offspring P1

10. GENETIC EXPERIMENTS P1
____ generation (parental)
____ generation
(filial=offspring)
___ generation F1 F2

11. GENETIC EXPERIMENTS
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12. When Mendel crossed PURE PLANTS with 2 choices for a trait:
He found
1. ___________________________________
BUT
2. ___________________________________
Only one trait showed in the F1 generation
Missing trait reappeared in the F2 generation in a 3 to 1 ratio

13. Mendel decided that there must be a_______ of “factors” controlling each trait and that one factor must be able to _______ the other.
pair
hide

14. We now know that Mendel’s “factors” are _________ carried
on the pair of________________
_________________
genes
homologous
chromosomes

15. _______________
are different gene
choices for a trait.
ALLELES

16. DOMINANT
__________________ = An allele that MASKS the presence of another allele
__________________ = An allele that IS MASKED BY the
presence of another allele
RECESSIVE

17. WHAT DOES MEIOSIS HAVE TO DO WITH IT?

18. MENDEL’S LAWS SEGREGATION LAW OF ____________________
The pair of factors is segregated (or separated) during the formation of gametes.
SEGREGATION
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19. LAW OF __________________________
the factors are distributed to gametes independently of other factors
INDEPENDENT ASSORTMENT
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20. MEIOSIS MENDEL’s LAWS of SEGREGATION & INDEPENDENT ASSORTMENT
happen because of the
way the chromosomes
move during
__________________
MEIOSIS

21. GENETIC CROSSES 9-2

22. DOMINANT/RECESSIVE T t capital lower-case NOT S for short
Dominant gene is represented by a ____________ letter. (usually the first letter of the trait)
Recessive gene is represented by the SAME
_________________ letter.
EX: Tall = ______
Short =______
capital
lower-case T t
NOT S for short

23. HOMOZYGOUS HETEROZYGOUS
When both alleles in the pair are the SAME the organism is _______________ or __________
EX: TT or tt
When both alleles in the pair are DIFFERENT the organism is
_________________ or _____________
Ex: Tt
HOMOZYGOUS PURE
HETEROZYGOUS HYBRID

24. PHENOTYPE/GENOTYPE
The genetic makeup of an organism is its _____________
The appearance of an organism is
its _____________
GENOTYPE
PHENOTYPE

25. Animation from:
PUNNETT SQUARES
are used to show possible offspring of a cross between 2 parents
Parent genes go at top and on left side
Boxes show possible
combinations

26. PROBABILITY
____________________ is the likelihood that a specific event will occur
It can be written as a:
Fraction 1/4
Percent 25%
Ratio 1:3

27. IN PEA PLANTS
Tall is dominant over short
TALL = ____
SHORT = ____ T t

28. PURE TALL parent What genes can it give?
T T _________
HOMOZYGOUS   T T

29. T T

30. PURE SHORT parent What genes can it give?
t t _________
HOMOZYGOUS   t t

31. T T t t T t T t T t T t ALL of the offspring 4/4 100% will be Tt TALL
GENOTYPE _____ PHENOTYPE _______

32. HYBRID TALL parent What genes can it give?
T t _________
HETEROZYGOUS   T t

33. T t

34. T t T t T t T T T t t t GENOTYPES ¼ = _____ TT ½ = _____ Tt tt 3/4 1/4
TALL
PHENOTYPES _______ ____________
_______ ____________
1/4
SHORT

35. MAKING A CROSS with only ONE gene trait = ____________________
MONOHYBRID CROSS
A Punnett square for a MONOHYBRID CROSS looks like this:

36. TESTCROSS used to tell what genes an organism has
Cross an UNKNOWN parent with a ____________________________
and see results
Offspring give a clue about the
unknown parent’s genes
HOMOZYGOUS RECESSIVE

37. TESTCROSS used to tell what genes an organism has
Example: The genes of a TALL PARENT are UNKNOWN
- COULD HAVE _____ TT Tt

38. TESTCROSS Tt tt t Tt Tt 50% will be TALL All offspring will
50% will be SHORT
All offspring will
be TALL

39. DEAF DOGS
Deafness in dogs is caused by a recessive allele. Deaf dogs have the genotype dd.
A HEARING dog could have 2 possible GENOTYPES
______ ______
How do we tell which one it is? Dd DD

40. TESTCROSS DEAF PARENT WITH PURE HEARING PARENT
D D
D d d
Hear Hear
Hear Deaf
Hear Deaf d
If you get some deaf puppies, you know parent was Dd.

41. GENES are more complicated than MENDEL thought
Some traits have more than two allele choices
EX: eye color

42. GENES are more complicated than MENDEL thought
Some traits are determined by more than one gene
EX: Human height

43. GENES are more complicated than MENDEL thought
Traits determined by more than one gene have lots of “in-between” phenotypes
There aren’t just SMART people
and DUMB people….
there is a whole range
of intelligences in-between

44. GENES are more complicated than MENDEL thought
KINDS OF DOMINANCE
____________________
COMPLETE DOMINANCE
INCOMPLETE DOMINANCE
CO-DOMINANCE

45. COMPLETE DOMINANCE Dominant allele masks the recessive one
Recessive allele returns in a 3:1 ratio in the F2 generation

46. INCOMPLETE DOMINANCE Don’t see expected 3:1 ratio in F2 generation
Organisms with one dominant and one recessive allele show a blended in-between trait

47. INCOMPLETE DOMINANCE ALLELES BLEND to produce an INTERMEDIATE
PHENOTYPE
Don’t see the expected
3:1 ratio in the F2 generation

48. CO-DOMINANCE
Both traits are expressed at same time (NO BLENDING) in heterozygote
Has BOTH
RED hair and WHITE hair

49. CO-DOMINANCE
Both traits are expressed together (NO BLENDING) in heterozygote
Persons with an A gene AND a B gene have blood type AB

50. BLOOD TYPES have more than 2 allele choices
Proteins with SUGARS attached help cells recognize ___________
Called
_______________
“self”
GLYCOPROTEINS

51. BLOOD TYPES have more than 2 allele choices
The protein and sugar that is attached is determined by genes
Allele choices are:
_____ ____ ____ B A O

52. BLOOD TYPES An A gene tells the cell to put “A” glycoproteins
on its surface

53. BLOOD TYPES An B gene tells the cell to put a
different “B” glycoprotein
on its surface

54. BLOOD TYPES An O gene tells
the cell NOT to put anything on the surface

55. A and B are CO-DOMINANT A cell with an A and a B gene has BOTH
glycoproteins on its surface

56. BLOOD TYPES & ALLELES
ALLELE
BLOOD TYPE AA A AO BB B BO OO O AB

57. BLOOD TYPES IMMUNE SYSTEM ATTACKS! YOU’RE NOT DIFFERENT FROM ME!
YOU ARE NOT ME!
IMMUNE SYSTEM ATTACKS!
YOU’RE NOT DIFFERENT FROM ME!
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58. BLOOD TYPES IMMUNE SYSTEM ATTACKS! YOU’RE NOT DIFFERENT FROM ME!
YOU ARE NOT ME!
IMMUNE SYSTEM ATTACKS!
YOU’RE NOT DIFFERENT FROM ME!
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59. BLOOD TYPES YOU’RE LIKE ME! IMMUNE SYSTEM ATTACKS!
YOU ARE NOT ME!
IMMUNE SYSTEM ATTACKS!
YOU’RE LIKE ME!
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60. BLOOD TYPES YOU’RE NOT DIFFERENT FROM ME!
O can donate to EVERY BLOOD TYPE
= UNIVERSAL DONOR!
Nothing on surface to
recognize as “NOT SELF”
YOU’RE NOT
DIFFERENT FROM ME!
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61. BLOOD TYPES AB can RECEIVE FROM EVERY BLOOD TYPE = UNIVERSAL RECIPIENT
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62. BLOOD TYPE FREQUENCY IN USA
40% B
10% AB 4% O
46%

63. OTHER BLOOD TYPES
Rh Rh-

64. OTHER BLOOD TYPES NO PROBLEMS IF: MOM is + & BABY is -
MOM & BABY are both +
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65. OTHER BLOOD TYPES PROBLEMS IF: MOM is - & BABY is +
1st baby OK but few baby cells
entering mom’s bloodstream
put mom’s immune system on
alert for + cells.
Next + baby, mom’s immune
system can attack baby as it is
growing
Shot after 1st birth prevents alert
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66. DIHYBRID CROSSES (2 traits)

67. MAKING A CROSS with TWO gene traits = ____________________
DIHYBRID CROSS
A Punnett square for a DIHYBRID CROSS looks like this:

68. HOMOZYGOUS ROUND YELLOW
HOMOZYGOUS WRINKLED GREEN X
r r y y
R R Y Y

69. POSSIBLE GAMETES?

70. POSSIBLE GAMETES?

71. RY RY RY RY RrYy ROUND YELLOW ry ry ry ry
RrYy RrYy RrYy RrYy
RrYy RrYy RrYy RrYy
RrYy RrYy RrYy RrYy RY RY RY
RrYy
100% of offspring = _______ genotype
_______________________ phenotype
ROUND YELLOW

72. HETEROZYGOUS ROUND YELLOWX
R r Y y
R r Y y

73. POSSIBLE GAMETES?

74. 9:3:3:1 9 RY 3 ry 3 rY Ry Sign of a heterozygous dihybrid cross is a
____ Round & Yellow
____ Round & green
____ Wrinkled & yellow
____ wrinkled & green 9 RY
RRYY RrYy RrYY RRYy
RrYy rryy rrYy Rryy RrYY RrYy rrYY rrYy
RrYy Rryy rrYy RRyy 3 ry 3 rY 1 Ry
Sign of a heterozygous dihybrid cross is a
_____________ ratio in offspring.
9:3:3:1

75. 9:3:3:1 9 3 3 1 ____ DOMINANT TRAIT 1 ; DOMINANT TRAIT 2
____ DOMINANT TRAIT 1; RECESSIVE TRAIT 2
____ RECESSIVE TRAIT 1; DOMINANT TRAIT 2
____ RECESSIVE TRAIT 1; RECESSIVE TRAIT 2 3 3 1
9:3:3:1