1. Genetics

2. 11.1 – Gregor Mendel

3. Heredity
Inheritance of traits
- study of heredity

4. Gregor Mendel Genetics Suggested carry inherited traits.
how traits were inherited by studying pea plants

5. The Role of Fertilization
- male and female reproductive cells to produce a cell.
In peas, this new cell develops into a tiny embryo encased within a seed. During sexual reproduction

6. The Role of Fertilization
Mendel decided to “cross” his stocks of true-breeding plants—he caused one plant to reproduce with another plant.

7. The Role of Fertilization
-breeding plants
Produce offspring to parent
- a specific characteristic
Ex) Seed color and shape.
Varies
In other words, the traits of each successive generation would be the same.

8. The Role of Fertilization
- Offspring of parents with different traits.
Mendel crossed plants with each of the seven contrasting characteristics and then studied their offspring.

9. Genes and Alleles gen – - Offspring of generation.
In each cross, one parent’s traits seemed to have
“first filial,”

10. Genes and Alleles
are by genes that are from parents to offspring.

11. Dominant and Recessive Traits
– Some alleles are dominant, others are recessive.
Express dominant trait if at least allele is present.
Express recessive trait if alleles present
Only recessive alleles present.

12. Organisms have alleles for each trait. One from . One from .
forms of a gene
Organisms have alleles for each trait.
One from .
One from
Egg and sperm are called gametes.

13. Segregation What happened to the recessive alleles?
hybrids self-pollinate.
Offspring of F1 called generation.
After F2 comes…. F3

14. The F1 Cross In plants, recessive traits .
of F2 plants had recessive trait.
Mendel assumed that a dominant allele had masked the corresponding recessive allele in the F1 generation.
The reappearance of the recessive trait in the F2 generation indicated that, at some point, the allele for shortness had separated from the allele for tallness.

15. Explaining the F1 Cross
Alleles segregated, or , during formation of the sex cells, or
Alleles for traits segregated

16. Recessive attached ear lobes
Dominant Free Ear Lobes
Hitch hiker’s thumb
Dominant
Tongue Roll Dominant trait
Regular thumb
Recessive

17. tall Seed shape Seed color Flower color Flower position Pod color Pod
Plant
height
Dominant
trait
axial
(side)
round
yellow
purple
green
inflated
tall
Recessive
trait
terminal
(tips)
wrinkled
green
white
yellow
constricted
short

18. 11.2 – Applying Mendel’s Principles

19. Dominant gene (allele)
Represented by letter
Written first
Example: for tall plant height

20. Recessive gene (allele)
if dominant genes present.
Represented with letters
Example: for short plant height

21. Pure (Homozygous)
Two of the genes (alleles) for a trait
Example: (homozygous ) or ( recessive)

22. Hybrid (Heterozygous)
Two alleles for a trait
Example:
Tall or short?

23. Probability – The likelihood that an event will occur.
Example: Flipping a coin
Probability of flipping heads? 1 2
Number of outcomes
Number of total outcomes

24. Probability Example: Flipping a coin
Probability of flipping heads three times?
½ x ½ x ½ =

25. Genotype
Combination of for a certain trait
Example:

26. Phenotype
How it physically looks
Example:

27. Genotype or Phenotype? Tt
Round
Black BB
Smooth rr
Tall

28. In pea plants, green (G) pods are completely dominant over yellow (g).
What are the genotypes?
Homozygous yellow
Heterozygous green
Homozygous dominant
Hybrid

29. In pea plants, green pods are completely dominant over yellow.
Pure yellow
Homozygous recessive
Pure green
Heterozygous
Yellow

30. In guinea pigs, short hair is dominant over long hair
What hair length will be represented by a capital S?
What hair length will be represented by a lower case s?

31. What phenotypes would result from the following genotypes?SS ss Ss

32. If both parents are pure, what are their genotypes?
Phenotypes of parents?
If both parents are pure, what are their genotypes?
Which allele will each parent pass on to offspring?
Phenotype of offspring?
Genotype of offspring?
All tall plants

33. homozygous round heterozygous wrinkled pure dominant hybrid round
In pea plants, round is dominant over wrinkled texture. What is the genotype of the following?
homozygous round
heterozygous
wrinkled
pure dominant
hybrid round

34. pure recessive heterozygous round pure wrinkled hybrid pure round
In pea plants, round is dominant over wrinkled texture. What is the genotype of the following?
pure recessive
heterozygous round
pure wrinkled
hybrid
pure round

35. Punnett Squares
Punnett squares – the from a cross.

36. Section 10.1 Summary – pages 253-262
Monohybrid crosses
Heterozygous
tall parent T t
Heterozygous
tall parent T t T t T t
Section 10.1 Summary – pages

37. How To Make a Punnett Square for a One-Factor Cross
Write the of the parents.
Ex) Cross a male and female bird that are heterozygous for large beaks. Genotypes of Bb.
Bb x Bb

38. How To Make a Punnett Square
Draw a Punnett square.
Put one parent on the , one parent on the
Put one from each parent on each side of each section.

39. How To Make a Punnett Square
Fill in the table by combining the gametes’ genotypes.
Mom
Dad

40. How To Make a Punnett Square
-Determine the genotypes and phenotypes of each offspring.

41. Probability of having…
A large beak?
A small beak?
Homozygous dominant?
Heterozygous?
Homozygous recessive?

42. Independent Assortment
Principle of – genes independently.
One gene effect another.
I.e. - Hair color does not effect eye color.

43. Dihybrid Cross
Two factor cross
involved.

44. The Two-Factor Cross: F1
Cross two true-breeding plants:
One produced only peas
One produced only peas.

45. The Two-Factor Cross: F1
peas had genotype Homozygous

46. The Two-Factor Cross: F1
peas had genotype
- Homozygous

47. The Two-Factor Cross: F1
All F1 offspring were
Shows yellow and round alleles are over green and wrinkled.
Punnett square shows genotype of F1 offspring as , for both seed shape and seed color.

48. The Two-Factor Cross: F2
Crossed plants to produce offspring.
Crossed with

49. Dihybrid cross instructions
Cross the parent alleles.
Outside has of each allele
Inside has alleles, two from each parent
Mom
Dad

51. The Two-Factor Cross: F2
Different genes each other’s inheritance.

52. The Two-Factor Cross: F2
Dihybrid cross has ratio.
Principle of – genes for different traits segregate independently.

53. 11.3 - Other Patterns of Inheritance

54. Neither gene is dominant phenotype is a blend.
Incomplete dominance
Alleles (mix)
Neither gene is dominant
phenotype is a blend.
Like colors of paint
Red + White = Pink

55. Incomplete Dominance R R W W
11-3

56. Codominance alleles are dominant expresses both.
There is NO “blending”
Red + White = Red and White

57. Red cow + white cow = roan cattle. Roan cattle have hairs.
Codominance

58. Codominance
Example:
White chicken (WW) x black chicken (BB) = black and white checkered chicken (BW)

59. Codominance

60. Incomplete or Codominance?
A white cow and a red cow produce a roan cow, one that has both white and red hairs.
A red flower and a white flower produce pink flowers.
A black cat and a tan cat produce tabby cats, cats where black and tan fur is seen together.

61. Incomplete or Codominance?
A blue blahblah bird and a white blahblah bird produce offspring that are silver.
A certain species of mouse with black fur is crossed with a mouse with white fur and all of the offspring have grey fur.
A woman with blood type A and a man with blood type B have a child with blood type AB.

62. Multiple Alleles
Single gene with alleles.
example: human blood type

63. Blood Types (codominant)
Blood type is codominant
and are dominant.
is recessive
4 different blood types
Phenotype
(Blood type)
Genotype
(Alleles or genes for blood type) A
IAIA, IAi B
IBIB, IBi AB
IAIB O ii

64. Polygenic Traits Traits controlled by genes of phenotypes.
example: human skin color has four different genes
Skin color genes: AaBbCcDd

65. Genes and the Environment
Genes provide a plan for development, but also depends on the environment.
Both
The characteristics of any organism are not determined solely by the genes that organism inherits.

66. 14.1 – Human Chromosomes

67. Karyotype
of chromosome .
Shows – full set of genetic information.

68. Karyotype
Normal Female

69. Karyotype
Female with Down Syndrome

70. Sex Chromosomes
chromosomes
Determine the sex of the offspring
Females are
Males are

71. Sex Chromosomes
All other chromosomes are
Everyone has 46 chromsomes: sex chromosomes and autosomes.

72. Sex-linked Traits
Traits inherited on X and Y chromosomes.
Most on chromosome
Ex) Color blindness recessive sex-linked trait on X-chromosome
show traits more than females
X chromo is bigger Males get only one X chromosome
Therefore, males show all recessive traits on X chromosome.
Females have a second X chromosome that carries another allele that can hide recessive traits

73. Heterozygous females are
Sex-linked Traits
Heterozygous females are
A woman can have normal vision but carry the recessive allele for colorblindness

74. X-Chromosome Inactivation
In female cells, one X chromosome is randomly switched off, forming a
Not found in because only have one X chromosome.
If just one X chromosome is enough for male cells, how does the cell “adjust” to the extra X chromosome in female cells?

75. Pedigree Study
Method of determining the genotype of individuals by looking at

76. Pedigrees illustrate inheritance
Male
Parents
Pedigrees illustrate inheritance
Siblings
Female
Affected male
Known heterozygotes for recessive allele
Affected female
Mating
Death

77. Human Pedigrees
This diagram shows what the symbols in a pedigree represent.

78. Human Pedigrees
This pedigree shows how one human trait—a white lock of hair just above the forehead— through three generations of a family.
The allele for the white forelock trait is

79. Human Pedigrees
Top of the chart is grandfather with the white forelock trait.
of his children inherited the trait.
grandchildren have the trait, but do not.

80. Human Pedigrees
Because the white forelock trait is dominant, all family members lacking this trait must have alleles.
One of the grandfather’s children lacks the white forelock trait, so the grandfather must be for this trait.