1. GENETICS 1

2. How did the study of Genetics begin?
Clip

3. Gregor Mendel
Genetics is the branch of biology that deals with heredity. A great deal of what we know about genetics began with the work of a monk named Gregor Mendel, who experimented with sweet pea plants in the 1800s. 2

5. 3
Mendel’s Work
Mendel studied the patterns of inheritance in pea plants.
He chose seven traits to follow.

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7. Mendel needed to make sure he had plants that always gave the same offspring-called true breeding.
He “self-pollinated” plants until he got seeds that always gave the same offspring. 5

8. Some plants can self-pollinate or cross-pollinate with another plant.6

9. He took a purple flower plant and crossed it with a white flower plant?
He called these the parent generation (P generation)
What do you think the offspring looked like?
Pollen X
ALL PURPLE 7

10. POLLEN F1
SAY WHAT??????? F2 8

11. 9
Mendel concluded:
2. Something is being passed from parent to offspring. He called these “Factors”
3. Sometimes you can see “it” and sometimes you can’t see “it”.
4. If you can see it- it is dominant.
1. If it’s there and you can’t see it- it’s recessive.

12. 5. There are two versions of these “FACTORS”. 10
5. There are two versions of these “FACTORS”.
6. To show the two version we use a capital letter for the dominant (S) version of the trait and a lower case for the recessive version (s) of the trait.
ADD TO NOTES: Each Version is called an Allele.

13. Each chromosome has many genes, but the alleles may be different11
Alleles are different versions of the same gene.

14. 12

15. Common Physical Human Traits- Different Alleles13
Trait
Dominant
Recessive
Chin cleft
Absent (C)
Present (c)
Dimples
Present (D)
Absent (d)
Earlobe shape
Free (F)
Attached (f)
Eye shape
Almond (A)
Round (a)
Eye position
Straight (S)
Upward slant (s)
Eyebrow position
Connected (Y)
Not connected (y)
Eyebrow shape
Bushy (B)
Fine (b)
Eyelash length
Long (L)
Short (l)
Face shape
Round (R)
Square (r)
Freckles
Present (P)
Absent (p)
Hair
Curly (H)
Straight (h)
Tongue rolling
Can roll (T)
Can't roll (t)
Widow's peak
Present (W)
Absent (w)
Activity

16. WHAT WE
KNOW
NOW 14

17. Chromosome
Anatomy 15

18. 16 We have two copies of all of our chromosomes Why?
These are called Homologous Chromosomes 16

19. BOY OR GIRL?
Karyotype
                                                                                        17

20. 18
DNA codes for Proteins

21. What is a gene? 19
A segment on the chromosome that codes for a protein.
People have two copies of each gene, one copy inherited from the mother and the other copy inherited from the father.
There are many versions of each gene-alleles

22. Remember:
Genes come in pairs.
**One from your mother
**One from your father.

23. If the two alleles in the pair are identical, then the condition called homozygous. The term “purebred” is sometimes used.
20.1

24. If the 2 alleles are different, the condition is called heterozygous
If the 2 alleles are different, the condition is called heterozygous. The term “hybrid” is sometimes used to refer to heterozygous. 20

25. 21 What the genes/alleles are …RR.…Rr
What the organism looks like…… Red…..White

26. Genotype
Phenotype

27. 22

28. Meiosis Review Animation
How did you end up with the traits and genes that you got?
During meiosis, each egg or sperm only gets one copy of each chromosome.
Meiosis Review Animation 23

29. 24
Law of Dominance
Mendel’s Laws
States that the dominant allele will prevent the recessive allele from being expressed.
The recessive allele will appear when it is paired with another recessive allele in the offspring.
Remember: Genes Come in Pairs!

30. Each gamete has only one allele of each gene pair. (haploid)
Law of Segregation (separation) states that gene pairs separate when gametes (sex cells) are formed
Each gamete has only one allele of each gene pair. (haploid)
Mendel’s Laws A b a B
S Phase A b A b a B a B
Makes a copy
gene pairs separate 25 A b A b a B a B
Goes through Meiosis

31. states that different pairs of genes separate
Law of Independent Assortment
states that different pairs of genes separate
independently of each other when gametes are formed. 26
Mendel’s Laws
Example:
Just because you get the gene for brown hair does not mean you will get the gene for blue eyes.
Animation

32. 27
REVIEW
A trait is a characteristic an individual receives from its parents.
Genes carry the instructions responsible for the expression of traits.
A pair of inherited genes controls a trait.
One member of the pair comes from each parent.
Alternative versions of genes are known as alleles.

33. REVIEW Mendel’s Principles of Inheritance
Inherited traits are transmitted by genes which occur in alternate forms called alleles
Principle of Dominance - when 2 forms of the same gene are present the dominant allele is expressed
Principle of Segregation - in meiosis two alleles separate so that each gamete receives only one form of the gene
Principle of Independent Assortment - each trait is inherited independent of other traits (chance) 28
Peas in a pod- Genetics Clip

34. Example EOCT Question:
Earlobe shape is a human trait. Some people have free earlobes while others have attached earlobes. Two parents with free earlobes have four children. Three children have free earlobes and one child has attached earlobes. If these parents have another child, what is the probability that the child will have attached earlobes?
A 25%
B 50%
C 75%
D 100% 32

35. Predicting possible outcomes of a genetic cross.30

36. Punnett Squares
Geneticist use punnett squares to determine the probability of a combination of alleles.
For example: If a heterozygous black rabbit is crossed with a heterozygous black rabbit, what are the chances the offspring will be black? 31

37. B=Black
b= Brown
Genotypes?
Phenotypes? 30

38. 31
Claymation Clip

39. Example EOCT question:
In humans, a widow’s peak is dominant over a continuous hairline. Mary’s father has a widow’s peak, but Mary and her mother have a continuous hairline. What is the genotype of Mary’s father?
A HH
B Hh
C hh
D cannot be determined 33

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41. Incomplete dominance is a cross between organisms with two different phenotypes produces offspring with a third phenotype that is a blending of the parental traits.  35

42. Incomplete Dominance 36

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44. 38

45. Codominance
With codominance, a cross between organisms with two different phenotypes produces offspring with a third phenotype in which both of the parental traits appear together. 
DO NOT blend together. 39

46. Codominance Types Both phenotypes are expressed at the same time.
Example: Blood
Types
Genotype
Phenotype
IOIO
Type O
IAIO
Type A
IAIA
IBIO
Type B
IBIB
IAIB
Type AB
There are 3 alleles for blood type- multiple alleles 40

48. Codominance R = allele for red flowers W = allele for white flowers red x white ---> red & white spotted 41

49.                                                                                                                                                  42

50. Many traits are controlled by more than one gene.
Polygenic traits
Many traits are controlled by more than one gene.
Ex: Skin Color 43

51. Sex Linked Traits
Traits associated with particular sexes are called sex-linked or X-linked traits.
Examples of Sex-linked Traits:
Red-green colorblindness
Hemophilia 44

52. Linked Genes 45 Occurs when particular alleles are inherited jointly.
They tend to be inherited together, for example, red hair and freckles.

53. 1st 22 are Autosomes, the last pair (XY) are sex chromosomes)
Karyotype 46

54. Charts that show relationships within a family
Pedigree 47

55. 47

56. How many boys? __________________
How many Girls? __________________
How many generations? _______________
How many with the disorder? ____________
How many marriages are shown? ____________ 13 12 3 4 6

57. 48 How many generations? How many carriers? How many affected males?
How many affected females?
Autosomal or sex-linked? 48

59. What can you tell by the pedigree?
Autosomal-Dominant
What can you tell by the pedigree?
Dominant or recessive?
Autosomal or sex-linked?

60. What can you tell by the pedigree?
SEX-LINKED
What can you tell by the pedigree?
Dominant or recessive?
Autosomal or sex-linked?

61. What can you tell by the pedigree?
SEX-LINKED
What can you tell by the pedigree?
Dominant or recessive?
Autosomal or sex-linked?

62. Autosomal or sex-linked?
Dominant or recessive?
Autosomal or sex-linked?
Autosomal -Dominant
NO carriers when Dominant.

63. Carriers when recessive.
Autosomal -Recessive
Carriers when recessive.

64. Pedigree Practice-Smart board

65. Genetic Disorders 49

66. Huntington’s Disease 49 1/2
Progressive, degenerative disease that causes certain nerve cells in your brain to waste away.
Experience uncontrolled movements, emotional disturbances and mental deterioration.
No cure. Fatal. ages:30-60
Dominant Allele
49 1/2

67. Colorblindness Sex-linked trait
Gene for color vision located on the X chromosomes.
Males are more likely to have colorblindness because they have only one X chromosome 50

68. What do you see? What do you see? 51
The individual with normal color vision will see a 5 revealed in the dot pattern. An individual with Red/Green (the most common) color blindness will see a 2 revealed in the dots. 51

69. 52

70. TEST 53

71. Down Syndrome Sister chromatid DO NOT separate during Meiosis.
3 copies of chromosome #21.
Sister chromatid DO NOT separate during Meiosis.
(or homologues fail to separate )
Nondisjunction
Also called: Trisomy 21 54

72. Nondisjunction Sister chromatid DO NOT separate during Meiosis.
Or homologues fail to separate during Meiosis.

73. Down Syndrome - Trisomy 2155

74. 56

75. Nondisjunction 57

76. Down Syndrome 58

77. Cystic Fibrosis
CF is caused by a recessive allele on chromosome #7.
More than 1,000 different mutations in the CFTR gene have been identified
Deletion of 3 bases.
Affects the body's respiratory and digestive systems.
59.1

78. Cystic Fibrosis 59.2 1 in 29 Caucasian Americans have the allele.
Asian & African-less likely to have.
More than 10 million Americans carry the cystic fibrosis gene
Treatments:
Pancreatic enzyme replacement therapy to allow proper food digestion
Bronchodilators (also used by people with asthma) that help keep the airways open
Inhaled antibiotics to kill the bacteria that cause lung infections
Chest physical therapy, in which the patient is repeatedly clapped on the back to free up mucous in the chest
Gene therapy ?????? Currently in clinical trials
59.2

79. Hemophilia 60 Recessive allele Sex-liked Trait (X chromosome)
more commonly in males
Located on the X chromosome
Missing a protein necessary for blood clotting
Major bleeding from minor cuts. 60

81. 61

82. Mis-shaped blood cells.
Sickle Cell
People who carry the tendency to have sickle cell anemia are less likely to die from malaria.
Mis-shaped blood cells. 62

83. Mis-shaped blood cells.
Sickle Cell
Mis-shaped blood cells.
Most commonly affects African-Americans.
About 1 out of every 500 African-American babies born in the United States has sickle cell anemia.
Interesting fact:
Unlike normal red blood cells, which can live for 120 days, sickle-shaped cells live only 10 to 20 days. 63

84. Tay-Sachs
Progressively destroys nerve cells (neurons) in the brain and spinal cord.
Harmful quantities of a fatty acids accumulate in the nerve cells of the brain.
Caused by insufficient activity of an enzyme called beta-hexosaminidase A that catalyzes the biodegradation of acidic fatty materials
More common in people of Ashkenazi (eastern and central European) Jewish heritage
Fatal 64

85. Gene Therapy 65

86. Example EOCT question:
What is nondisjunction?
A. failure of chromosomes to separate during meiosis
B. failure of the cytoplasm to divide properly
C. the insertion of a gene into a different chromosome
D. the deletion of a gene from a chromosome 66

87. B gene  chromosome protein C cell respiration  ATP  protein
Which of the following shows how information is transformed to make a protein?
A DNA RNA  protein
B gene  chromosome protein
C cell respiration  ATP  protein
D ATP  amino acid  protein 67

88. Information on mRNA is used to make a sequence of amino acids into a protein by which of the following processes?
A replication
B translation
C transcription
D transference 68

89. phenotypic ratio of the offspring?
Pea plants have seeds that are either round or wrinkled. In this cross, what will be the
phenotypic ratio of the offspring?
A 50% RR and 50% Rr
B 25% RR, 50% Rr, and 25% rr
C 50% round seeds and 50% wrinkled seeds
D 100% round seeds 69

90. What is a source of genetic variation? A mutation B adaptation
C replication
D transcription 70

91. and reappeared in the next generation is called the
In Mendel’s experiments with a single trait, the trait that disappeared in the first generation
and reappeared in the next generation is called the
A homozygous trait
B dominant trait
C recessive trait
D heterozygous trait 71

92. What pattern of inheritance is this?72

93. Human Genome Project

94. What would one gene say to another?

95. FIN

98. Cloning