1. Bellwork: 4/18 Put your phone up 
Week 4/15 - 4/19
Quiz Day – you have 2 min to look over notes

2. Today:
Quiz
Part 6 Notes
Pedigree Practice
Video

3. Materials
Unit Book
Pedigree Packet

4. This Week: Monday: Pt. 5 Notes & Practice
Tues/Wed: Sex-Link Quick Lab & Movie
Thursday: Quiz, Pt. 6 Notes, & Practice
Friday: Practice & White Board Practice

5. Next Week: Monday: Study Guide (maybe Kahoot) Tues/Wed: Test
Thursday: Presentations
Friday: Presentations

6. Homework Genetics Project Unit 6 Test Study Guide & All Late Work
Due 4/24 at 11:59pm
Unit 6 Test
Period 4 & 6: April 23
Period 5 & 7: April 24
Study Guide & All Late Work

7. Unit VI: Mendelian Genetics

8. Part 6: Human Genetics

9. Human Genetics
We can follow specific genetic traits by examining family members across generations through pedigree analysis
More recently, genetic testing has allowed inheritance of genetic diseases to be determined

10. Pedigree Analysis
Pedigree Analysis – family tree that records & traces the occurrence of a trait in a family through several generations

11. Symbols Used Symbols used: Squares – males Circles – females
Horizontal Line – indicates a mating event
Each level of the tree represents a generation

12. Symbols Used Symbols used:
Vertical line - represents offspring produced
Offspring are listed in birth order from left to right
Shaded symbols indicate individuals with the trait being traced

13. Solving Pedigree Analysis Problems
If parents without trait have offspring with trait, parents carriers
Trait observed in every generation – dominant trait
Exception: if trait recessive & both parents have it then all the children in the next generation have it
Knowing these general rules, identify individuals where the genotypes can be determined based on pedigree
Go back & identify genotypes that are incomplete. For example, you know at least one allele is dominant but unable to determine second allele
Indicate with a ?

14. Sample Problem
The ability to taste phenylthiocarbamide (PTC) is controlled by a single dominant allele (T). A woman non-taster married a man taster & they had three children, two boy tasters & a girl non-taster. All the grandparents were tasters. Create a pedigree for this family for this trait. (Solid symbols should signify non- tasters (tt))

15. Genetic Testing
Sequencing the human genome has open new opportunities for genetic testing
Genetic Testing involves examining your DNA for changes or alterations that could cause illness or disease
Tests are done on collected blood or other tissues

16. Genetic Testing Used for:
Identifying genetic diseases in developing fetuses
Identifying if potential parents are carriers of a genetic disease
Screen newborns for genetic diseases
Screening embryos produced in vitro fertilization before implantation
Testing adults for genetic diseases before symptoms arise
Making a definitive diagnosis for an individual who shows disease symptoms

17. Genetic Disorders
Arise when mutations occur and are passed down to subsequent generations

18. Genetic Disorders Classified based on where mutation occurred
Two types
Autosomal – mutation associated with chromosomes 1-22
Sex-linked – mutation associated with sex chromosome

19. Autosomal Dominant Disorder
Characteristics:
Every individual with condition will have a parent with condition

20. Autosomal Dominant Disorder
Marfan Syndrome:
Cannot make protein called fibrillin – weakens body structure
Phenotype:
Tend to be tall
Have long fingers
Long arms
Weakened aorta – main blood vessel from heart

21. Autosomal Dominant Disorder
Achondroplasia:
Form of dwarfism
Individuals seldom reach 5 ft. in height
Disorder of bone growth
Most cases, result of spontaneous mutation
Symptoms
Short stature
Bowed legs
Disproportionate large head to body size

22. Autosomal Recessive Disorder
Characteristics:
Individual with the condition can have one, two, or neither parent exhibit the condition
If homozygous recessive – person will have the condition
If heterozygous – the individuals are carriers

23. Autosomal Recessive Disorder
Methemoglobinemia:
Defective enzyme diaphorase
Relatively harmless disorder
Results from accumulation of methemoglobin in the blood
Hemoglobin, oxygen carrying protein in blood gives blood its red color
Hemoglobin slowly converted to methemoglobin (has bluish color)
Diaphorase converts methemoglobin back to hemoglobin

24. Alteration in Chromosome Number
Nondisjunction - occurs when either homologous chromosomes or sister chromatids fail to separate during anaphase of meiosis or mitosis

25. Think
Draw a diagram of meiosis & show what happens when the homologous chromosomes fail to separate.

26. Nondisjunction & Meiosis

27. Example of Nondisjunction
Down Syndrome
Cells have 3 copies of chromosome 21 rather than 2

28. Karyotype of Down Syndrome

29. Other Examples of Nondisjunction
Klinefelter Syndrome - XXY
Phenotype – male; sterile; breast enlargement
Supermale – XYY
Phenotype - high level of testosterone; tall; severe acne; tends to have increase violence