3. Warm Up
Identify each of the following as homozygous dominant, homozygous recessive or heterozygous. Hh Kk ll jj DD
6. What is the genotype of the father in this punnett square?
7. What’s the genotype of the mother?
8. What’s the probability of a child being homozygous recessive? PP Pp

4. Agenda
Objectives: SWBAT: use a Punnett square to determine the possible allele combinations for an individual, identify dominant and recessive traits given the results of a monohybrid cross AND determine the probability that an organism will have express a particular trait given its genotype.
Notes
Go over grades/ Pass out Progress Reports
White Board Practice
Genetics Practice Problems Sheet

5. Grades Reminders Pass out Progress Reports
This is the last week of the quarter, you need to earn a passing grade so that you do not have to retake Biology I. Turn in all missing work by Wednesday, and everything this week ON TIME.
Pass out Progress Reports
If you are unhappy with your grade, come in during lunch or after school to retake a quiz or test

6. White Board Review

7. When Mendel crossed tall plants with short plants, all of the offspring were tall. The trait for tall plants is considered _______________

8. The trait for short plants is considered _______________

9. If we were to use the letter “T” to write the genotype of the plants, the short plants would be ______

10. Is the genotype for short plants homozygous or heterozygous?

11. If we were to use the letter “T” to write the genotype of the plants, the tall plants would be ______

12. Is the genotype for tall plants homozygous or heterozygous?

13. Draw the Punnett square of a homozygous tall plant with a homozygous short plant and fill in the boxes.

14. What percent of the offspring have a heterozygous genotype?

15. What percent of the offspring will be short?

16. Clean up white boards

17. Review
Being allergic to poison ivy is due to a recessive gene. Say a mom is homozygous recessive and the dad is heterozygous. Use the letter “I” or “I” to draw a Punnett square. Answer the following questions:
a. What’s the probability that their child will be allergic to poison ivy?
b. What one trait did we study in this example?

18. Review

19. Genetics Review Worksheet

20. Exit ticket
Being allergic to Poison Ivy is caused by a recessive trait.
If a person has a genotype of Ii, will he or she be allergic?
What is the phenotype for ii?
Draw a Punnett square to show the possible offspring for a man with Ii and a woman with Ii.

21. Warm- Up
Get out your Reading Guides- I will collect them as I stamp your work.
Brown fur is dominant to white fur in a type of bunny. Draw a Punnett square to show a cross between a homozygous recessive dad and a heterozygous mom.
What is the probability that their bunnies will have white fur?
What genotype(s) in the offspring will code for brown fur?

22. Agenda
Objectives: SWBAT: Analyze a dihybrid cross to determine the probability of a particular trait, given completed Punnett square
Go over and turn in homework
Notes
Practice Problems
Exit Ticket
Calendar
Dihybrid practice due tomorrow
Quiz on Friday

23. Monohybrid Crosses
Up to this point, we have only been looking at monohybrid crosses
Two parents are mated (hybrid)
We only examine one trait (mono)
Today we’re going to start looking at dihybrid crosses

24. What is a Dihybrid Cross?
a. “Di” means _________
b. A dihybrid cross is used to determine the possible offspring of two parents based on two traits.

25. c. In this example:
Coat color is indicated by B for brown coat or b for white coat while
Tail length is indicated by S for short tail or s for long tail.

26. Practice Questions d. How many boxes show a cat with brown fur?
( ____ / 16)
e. How many boxes show a cat with white fur?
f. How many boxes show a cat with a long tail?
g. How many boxes show a cat with a short tail?

27. Practice Questions
h. How many boxes show a cat with brown fur and a short tail?
How many boxes show a cat with brown fur and a long tail?
How many boxes show a cat with white fur and a short tail?
How many boxes show a cat with white fur and a long tail?

28. How do we fill in a Dihybrid Cross?

29. Construct a Dihybrid Cross
a. Brown fur (BB) is dominant over white fur (bb)
b. Long hair (LL) is dominant over short hair (ll)
c. What are the 4 possible combinations?
BL, Bl, bL, bl

30. Construct a Dihybrid Cross
If one parent has a genotype of BbLL and the other is Bbll, how would we fill in a Punnett Square?

32. Dihybrid practice sheet

33. Exit Ticket
For peas, we want to figure out the possible offspring of a plant with Yy (yellow seed color) and tt (short) and a plant with yy (green seed color) and TT (tall). Draw a dihybrid cross to show the possible offspring.

34. Warm Up
Can traits be passed down in a family? Who can we inherit traits from?
What is a family tree?
What’s the difference between a dihybrid cross and a monohybrid cross?
How many traits are studied in a dihybrid cross?

35. Agenda
Objectives: SWBAT: Identify the sex chromosomes in humans and recognize inheritance patterns that are sex-linked, using a pedigree or scenario
Go over Dihybrid homework
Notes
Practice
Exit Ticket
Reminder
Quiz Friday!

36. What are Pedigrees?
Pedigrees are charts used to show how a trait is passed over several generations in a family
b. Pedigrees look like family trees

37. Example

38. What are the Sex chromosomes?
There are two different sex chromosomes: X and Y
Females have the chromosomes XX
Males have the chromosomes XY
Where do we get the first X chromosome from?

39. What are Sex-Linked Traits?
a. Certain traits are called sex-linked because the traits are determined by genes on the X and Y chromosomes (the sex chromosomes).
b. Most sex-linked traits are only found on the X chromosomes.

40. What are the Sex chromosomes?
c. Genetic diseases or mutations are carried on the X chromosome.
Females are more likely to be carriers because they have two X chromosomes
Males are more likely to inherit genetic diseases because they only have one X chromosome

41. What are Sex-Linked disorders?
a. Colorblindness and hemophilia are sex-linked genes.
b. Colorblindness occurs in 1 out of 10 males in the US and 1 out of 100 females in the US.

42. Video

43. How do we read Pedigrees?
a. Circles stand for females and squares stand for males
b. Horizontal lines between two people represent that they have had children
c. Vertical lines connect the children to the parents

44. How do we read Pedigrees?
d. Shapes that are filled in express the trait
e. Shapes that are NOT filled in do NOT express the trait
f. If a person is heterozygous for a trait, then he or she is also called a carrier.
- Carriers are represented by half filled in shapes

45. Example

46. Copy down the Pedigree Key
Gender Phenotype Genotype
F normal XX
F carrier XXa
F affected Xa Xa
M normal XY
M affected XaY

47. Practice: Example 1

48. Practice: Example 2
Hemophilia
Hemophilia

49. Warm Up
1. 2.

50. Agenda
Objectives: SWBAT: Identify the sex chromosomes in humans and recognize inheritance patterns that are sex-linked, using a pedigree or scenario
Watch couple videos
Practice Problems
Finish Worksheet
Exit Ticket
Review for Quiz

51. Videos

52. Review
Two of our 46 chromosomes are known as sex chromosomes because they determine an individual’s sex (male or female).
Males have an XY genotype. Females have an XX genotype.
The sex chromosomes are the 23rd pair of chromosomes.
The other 22 pairs of chromosomes are called autosomes.

54. Practice Problems
6. 3 and 4 are ___________ 7. Which offspring of parents 5 and 6 are colorblind? 8. All the individuals that have normal color vision 9. All the individuals that are colorblind

55. Practice Problems How many males are normal? ________
How many males are affected? ________
How many females are normal? ________
How many females are affected? _______
How many females are carriers? _______

56. How do we write the genotype?
Males will always be XY and females will always be XX
We write the genotype as an “exponent” on the X chromosomes
Examples: XhY XHXh

57. Practice Problems
10. All the individuals that are carriers 11. The only person that has colorblindness is a male or female? Why? 12. If colorblindness is caused by a recessive allele (Xc) and the allele for normal color vision is dominant (XC), which people are XC Xc ?

58. What can Pedigrees show?
Pedigrees can be used to show:
Sex-Linked genes
Autosomal disorders

59. What are Autosomal Disorders?
An autosomal disorder is found on an autosome
- Disorders can be caused by dominant or recessive alleles
Examples
Cystic Fibrosis
Albinism
Tay-Sachs disease
Sickle Cell Anemia

60. Sickle-Cell Anemia
A person with sickle cell anemia has two recessive alleles (ss) AND is resistant to malaria!!!
b. A person that is heterozygous (Ss) does NOT have sickle cell. They are ALSO resistant to malaria!!!
c. A person that is homozygous dominant (SS) doesn’t have sickle cell and is NOT resistant to malaria

61. Map of sickle cell and malaria frequency

62. White Board Practice

63. Draw the symbol for carrier female

64. Write the genotype of a male with hemophilia (which is caused by a recessive gene)

65. A couple wants to know if their child is going to have curly or straight hair. The husband is heterozygous for curly hair and the wife has straight hair. What’s the probability that their children will have straight hair?

66. What percent of the offspring are homozygous recessive?GG Gg gg

67. If the dominant fur color is gray and the recessive fur color is black, what’s the probability of the offspring having black fur? GG Gg gg

68. In certain breeds of dogs, deafness is due to a recessive allele (d) of a particular gene, and normal hearing is due to its dominant allele (D). What percentage of the offspring of a normal heterozygous (Dd) dog and a deaf dog (dd) would be expected to have normal hearing?

69. The following genotypes were found in a male cat and a female cat: BbSs (male) bbSS (female)
Which one of the following choices is true of the phenotype of offspring from these parents?
All offspring will have black fur.
All offspring will have white fur.
All offspring will have long-haired fur.
All offspring will have short-haired fur.

70. Hemophilia is a sex-linked recessive disease
Hemophilia is a sex-linked recessive disease. If a woman is XRXr does she have it?

71. If a man is XrY does he have hemophilia?

72. A woman is XRXr and a man is XrY, what’s the probability that their children will have it?

74. A pregnant couple wants to know if their child will have dimples
A pregnant couple wants to know if their child will have dimples. Having dimples is a dominant trait. The mother has the cutest dimples and so do her parents. The father however, does not have dimples. What’s the probability that their child will have dimples?

75. Autosomal or sex-linked disorder?

76. Exit Ticket
Get out a half sheet of paper with your name, date and period at the top right hand corner

77. Exit Ticket How many people are affected?
How many people are carriers?
Draw the symbol for a female carrier
Draw the symbol for a normal male

78. Friday Agenda and Announcements
Today
Turn in Bellwork
Review Dihybrids and Pedigrees
Quiz
Next Week
Different types of inheritance
Begin review for the semester exam

79. Get out your notes from December 1st
Turn your paper to the backside.
Look at the dihybrid cross that you filled in.

80. Check to make sure it’s right!
BBLL
BBLl
BbLL
BbLl
BBll
Bbll
bbLL
bbLl
bbll

81. Use the colored pencils at your table
Pick 4 different colors
Color in all the boxes with genotypes for long, white hair with 1 color
Color in all the boxes with genotypes for long, brown hair with 1 color
Color in all the boxes with genotypes for short, brown hair with 1 color
Color in all the boxes with genotypes for short, white hair with 1 color

82. Analyze the dihybrid cross
What fraction of the cats will have long brown hair?
What fraction of the cats will have long white hair?
What fraction of the cats will have short brown hair?
What fraction of the cats will have short white hair?

84. Genetics worksheet
Get out a separate sheet of paper to use for drawing punnett squares
We’re going to do 1 and 2 together. You will do the rest on your own.
We’ll go over the answers before we take the quiz.