2. Pioneer of genetics: Gregor Mendel
Studied patterns of inheritance in pea plants
Studied characteristics like:
Flower color, seed color/shape, pod color/shape, height of stem

6. Mendel identified the role of complete dominance
Mendel identified the role of complete dominance. (one trait is completely dominant over the other)

7. Trait: Specific characteristic (seed color, plant height)
Generally controlled by 2 alleles of a gene

8. Gene:
Factors that determine traits (Sections of DNA)

10. Allele
Different forms of a gene

11. Genotype:
Combination of alleles inherited from parents

12. Phenotype:
Physical appearance of the genotype (adjective)
Ex/ purple petals, white petals, freckles, blonde hair, brown hair, dimples

13. Genotypes and Phenotypes can be found by determining the alleles that were passed down from the parents

14. Represented by a capital letter
Dominant Allele:
Produces a dominant phenotype in individuals who have at least one copy of the dominant allele
Represented by a capital letter
P = purple petal color

15. Represented by a lowercase letter
Recessive Allele
For a recessive allele to produce a recessive phenotype, the individual must have TWO copies of the recessive allele
Represented by a lowercase letter
p = white petal color

16. What possible genotypes would produce the phenotypes?
P = purple
p = white
Genotype
Phenotype

18. Heterozygous:
Organisms that have two DIFFERENT alleles for the same trait (hybrid)
The presence of the dominant allele will produce the dominant phenotype

19. Homozygous:
Organisms that have two IDENTICAL alleles for a particular trait (purebred)
The phenotype will be determined by whether they have two dominant alleles or two recessive alleles

20. Let’s Practice!
= b
= B
GENOTYPE
PHENOTYPE

21. Can you predict the gentotypic and phenotypic outcome of a fertilization?

22. Following traits through generations:
P : Parent generation
F1: 1st filial (1st set of offspring from parents)
F2: 2nd filial (offspring of second generation)

24. Punnett Square:
Grid that shows probable outcome of a genetic cross (fertilization)

25. yy x Yy Ff x Ff One Factor Cross (Monohybrid Cross)
Considers one trait
Freckles on face
F = freckles
f = no freckles
Pea Pod Color
Y = yellow
y = green
yy x Yy
Ff x Ff

26. Two Factor Cross (Dihybrid Cross): Considers two traits
Ex/ Pea shape and pea color
R = round r = wrinkled
Y = yellow y = green

28. Should This Dog Be Called Spot?
Practice

29. Genotype
Phenotype

30. SpongeBob Square Pants Bikini Bottom Worksheet

38. SpongeBob Square Pants Bikini Bottom Worksheet#2

39. Mendelian Inheritance in Humans

40. Middigital Hair
The presence of mid-digital hair is a dominant condition; therefore those lacking it are homozygous recessive.

41. Freckles
Freckles are controlled primarily by the MC1R gene. Freckles show a dominant inheritance pattern: parents who have freckles tend to have children with freckles.
Variations, also called alleles, of MC1R control freckle number.
Other genes and the environment influence freckle size, color, and pattern. For example, sun exposure can temporarily cause more freckles to appear.
Freckles are small, concentrated spots of a skin pigment called melanin. Most fair-skinned, red-haired people have them.

42. Tongue Rolling
Many sources state that tongue rolling is controlled by a single gene. However, as Sturtevant observed, people can learn to roll their tongue as they get older, suggesting that environmental factors—not just genes—influence the trait. Consistent with this view, just 70% of identical twins share the trait (if tongue rolling were influenced only by genes, then 100% of identical traits would share the trait).
Some people can curl up the sides of their tongue to form a tube shape. In 1940, Alfred Sturtevant observed that about 70% of people of European ancestry could roll their tongues and the remaining 30% could not.

43. Widow’s Peak A distinct downward peak of the frontal hairline
Having a widow’s peak is a dominant trait.
Homozygous recessive individuals possess a straight hairline.

44. Earlobe Attachment Is your earlobe attached or unattached?
Free or unattached earlobe is dominant.
The homozygous recessive condition is expressed as a direct attachment of the earlobe to the head.

45. Facial Dimples
Dimples are small, natural indentations on the cheeks. They can appear on one or both sides, and they often change with age. Some people are born with dimples that disappear when they’re adults; others develop dimples later in childhood.
Dimples are highly heritable, meaning that people who have dimples tend to have children with dimples—but not always. Because their inheritance isn't completely predictable, dimples are considered an “irregular” dominant trait. Having dimples is probably controlled mainly by one gene but also influenced by other genes

46. Hair Curliness
Round hair follicles make straight hair, flattened or c-shaped hair follicles make curly hair, and oval hair follicles make wavy hair. Hair texture is a continuous trait, meaning that hair can be straight or curly or anywhere in between. Curly hair is influenced by genes much more than by the environment. While curly hair runs in families—people with curly hair tend to have children with curly hair—its inheritance patterns are often unpredictable.
Multiple genes control hair texture, and different variations in these genes are found in different populations. For instance, curly hair is common in African populations, rare in Asian populations, and in-between in Europeans. Straight hair in Asians is mostly caused by variations in two genes—different genes from the ones that influence hair texture in Europeans. And different genetic variations make hair curly in African and European populations.

47. Hitchhikers Thumb Hyperextensibility of the thumb is recessive.
Those who cannot bend at least one thumb backward about 45 degrees are probably carrying the dominant gene.
Sorry… But no hitchhikers thumb…

48. PTC Tasting Can you taste the bitterness of the PTC paper?
People who can taste the bitterness are either homozygous dominant (TT) or heterozygous dominant (Tt).
People who cannot taste the bitterness are homozygous recessive.

49. Red-Green Color Blindness

50. Test Cross
Done to determine the genotype of a phenotypically dominant individual
(TT or Tt):
Cross individual with a homozygous recessive individual T t T t

51. P = Probability # of times an event occurs
The total number of possible outcomes
Ex/ flipping a coin: ½ heads
The larger the # of trials, the closer to the expected results
Previous events have no effect on future outcomes

52. Mendel’s Laws Law of Segregation
Parental genes are randomly separated to the sex cells so that sex cells contain only one gene of the pair. Offspring therefore inherit one genetic allele from each parent when sex cells unite in fertilization.

53. Not everyone with blonde hair will also inherit blue eyes!
Mendel’s Laws
Law of Independent Assortment
Genes for different traits are sorted separately from one another so that the inheritance of one trait is not dependent on the inheritance of another
Not everyone with blonde hair will also inherit blue eyes!

54. Mendel’s Laws Law of Dominance (complete dominance)
An organism with alternate forms of a gene will express the form that is dominant.

55. Incomplete Dominance
One allele is not completely dominant over the other
The heterozygous phenotype is somewhere in between the two homozygous phenotypes (blend)

56. Codominance Both alleles contribute to the phenotype “co-captains”
2 different alleles are dominant
Blood Types are an example
A- dominant (IA)
B- dominant (IB)
O- recessive(i)

58. Human Blood Groups Type Genotype Phenotype IAIA , IAi A “A” Antigens
RBC
Plasma
IAIA , IAi A
“A” Antigens
(AA) , (AO)
IBIB , IBi B
“B” Antigens
(BB) , (BO) ii O
No Antigens
(OO)
IAIB
Both “A” & “B” Antigens AB
(AB)
Universal Donor: O
Universal Acceptor: AB
isohaemaglutinogen

60. Rh FACTOR
RBC
Positive
Negative
plasma
No Rh antibodies
Rh antibodies

61. Rh Factor??

62. Approximate distribution of blood groups and types in the U. S
Approximate distribution of blood groups and types in the U.S. population
Blood Type
Rh POSTIVE
Rh NEGATIVE
total O
38% 7%
45% A
34% 6%
40% B 9% 2%
11% AB 3% 1% 4%
TOTAL
84%
16%
100%

63. Nobel Blood Typing

67. Sex-Linked Traits 3. Sex-linked traits:
Located on the X or the Y chromosome.
Because the Y chromosome of many organisms contains little genetic information, most sex-linked characteristics are X-linked.
Usually X-linked recessive
Written with the X chromosome

68. Example: Colorblindness
B = normal vision
b = colorblind
Female
Male
XBXB
Normal female
XBY
Normal male
XBXb
Carrier female
XbY
Afflicted male
XbXb
Afflicted female

71. Pedigrees
4. Pedigrees
Displays a family tree, and shows the members of the family who are affected by a genetic trait
Circles represent females and squares represent males
A male and female directly connected by a horizontal line have married
Vertical lines connect parents to their children.
A darkened circle or square represents an individual affected by the trait being looked at

74. Sex-linked Recessive Pedigree

75. D – dominant (normal)
d – recessive (muscular dystrophy)

77. 60 minutes – Breeding out disease

78. What could you do now? http://www.quia.com/quiz/4000500.html
Try a review quia quiz:
Work on genetics section of final review packet

79. Pedigree’s Review: A circle on a pedigree chart represents a:
Male
Female
Person who expresses the trait
A shaded circle or square represents a:
Person without the particular trait
Person who expresses the particular trait

80. Designer Babies

81. Pedigree’s
Which of the following pedigrees probably represents the inheritance pattern of a dominant trait?
Since the allele for colorblindness is located on the X chromosome, colorblindness:
Cannot be inherited
Is sex-linked
Can only be inherited by females

82. For the crosses shown, draw a Punnett square and calculate the probability for the genotype and phenotype for the crosses.
Trait
Dominant
Recessive
Seed coat shape
Round (R)
Wrinkled (r)
Pod color
Green (G)
Yellow (g)
Seed coat color
Brown (B)
White (b)
Height of plant
Tall (T)
Short (t)
Rr x rr
Rr x Rr
Cross 2 heterozygous green pod plants.
Cross a homozygous green pod plant with a heterozygous green pod plant.
Cross a homozygous tall plant with a short plant.