1. Genetics

2. 1. What chromosomal disorder is caused by a piece being lost?
Deletion

3. 2. What chromosomal disorder is caused by an extra piece of chromosome being added?
insertion

4. 3. What chromosomal disorder is caused by a piece breaking off & reattaching in the opposite order?
inversion

5. 4. What chromosomal disorder is caused by part of a chromosome breaking off and attaching to another chromosome?
translocation

6. 5. What chromosomal disorder is caused when a chromosome does not separate?
nondisjunction

7. 6. In what phases can nondisjunction occur and what is the result for the gametes?
Anaphase I
Anaphase II

8. 7. Make a dihybrid cross for the following: TtRr TTrr (T=tall; t=short; R=red; & r=white)
TR Tr tR tr
Tr TTRr TTrr TtRr Ttrr
Tr TTRr TTrr TtRr Ttrr
Tr TTRr TTrr TtRr Ttrr

9. 8. From the above dihybrid, how many tall red flowers were produced?
8-TTRr & TtRr=Tall & Red
8-TTrr & Ttrr= Tall & White
Equal 16 squares
TR Tr tR tr
Tr TTRr TTrr TtRr Ttrr
Tr TTRr TTrr TtRr Ttrr
Tr TTRr TTrr TtRr Ttrr
Tall/Red Tall/White Tall/Red Tall/White
Tall/Red Tall/White Tall/Red Tall/White
Tall/Red Tall/White Tall/Red Tall/White
Tall/Red Tall/White Tall/Red Tall/White

10. 9. What chromosomes are involved with autosomal conditions?
Pairs #1-22 (all but the sex chromosomes)

11. 10. A hypothetical disorder's location is written as 13q31. 5
10. A hypothetical disorder's location is written as 13q Answer the following questions using this information. What chromosome is the disorder located? 13

12. Units above orbelow the centromere
10. cont. Is the disorder above or below the centromere? If it said "p" instead of "q", would it be above or below the centromere? represents what?

13. Mental retardation, muscle weakness, heart defects & short stature
Brain/neurological, heart/circulatory and muscle
Chromosome 21 nondisjuntion causing trisomy 21
Answer the following questions for Down's Syndrome: List the 4 main characteristics- It affects what 3 systems the most? Which chromosome does it affect and what is the cause?

14. Lungs & digestive #7 autosomal recessive
12.Answer the following questions for Cystic Fibrosis: What 2 systems does it affect? Which chromosome and what type of autosomal disorder is it?
Lungs & digestive
#7 autosomal recessive

15. Answer the following questions for Sickle Cell Anemia: Describe the condition- What type of autosomal disorder and which chromosome?
Red blood cells are crescent shaped instead of round. This shape change does not allow them to bind to oxygen properly
Autosomal recessive chromosome #11

16. Answer the following questions for Huntington's Disease: Describe the condition- What type of autosomal disorder-
Deterioration of brain tissue in middle age (30’s & 40’s)
Chromosome #4 Autosomal Dominant

17. 15. If an offspring has an autosomal dominant disorder, what does that tell you about their parent?
1 or both parents have the disorder

18. 16. If both parents are heterozygous with an autosomal dominant disorder (they have the disorder), what is the likeliness for their offspring to have the disorder? (D=disorder & d=no disorder)
D d
D DD Dd
d Dd dd
Disorder Disorder
Disorder no disorder
75% with Disorder

19. 17. What is the likeliness for an offspring to get an autosomal recessive disorder if both parents have the disorder? (d=disorder & D=no disorder)
d d
d dd dd
(disorder) (disorder)
d dd dd
(disorder) (disorder)
100% disorder

20. 18. If both parents are carriers for an autosomal recessive disorder (they do not demonstrate the condition), what is the likeliness of the offspring getting the condition. What about the likeliness of being a carrier? (d=disorder & D=no disorder)
D d
D DD Dd
d Dd dd
no disorder carrier
carrier disorder
Disorder =1/4 or 25%
Carrier= ½ or 50%

21. 19. How can an autosomal recessive condition be hidden for generations?
The dominant allele hides it

22. 20. What chromosome number do sex-linked chromosomes occur on?
Pair #23

23. 21. Which chromosome do most sex-linked conditions occur and why?
Larger & carries more genes

24. 22. What type of chromosome does mothers give their offspring
22. What type of chromosome does mothers give their offspring? Their fathers?
Mother gives only “X’s” to their offspring
Fathers give X’s to daughters & Y’s to sons

25. 23. Who determines the offspring's sex?
Father

26. 24. Answer the following about Colorblindness: Description- Who is most commonly affected- Type of sex-linked disorder-
Can’t distinguish certain colors
Males
X-linked recessive

27. Blood does not clot
Males
X linked recessive
25. Answer the following about Hemophilia: Description- Who is most commonly affected- Type of sex-linked disorder-

28. Females short in stature, no puberty, or menstruation
X0-only 1 chromosome
Nondisjunction
Answer the following about Turner Syndrome: Description- Who is most commonly affected & chromosome combination- What type of sex-linked disorder-

29. 27. Answer the following about Klinefelter's Syndrome: Description- What type of sex-linked disorder & chromosome combination-
Hermaphroditic male & female reproductive organs but only 1 functional
Nondisjunction-XXY(usually)

30. 28. Who is more affected by X-linked recessive disorders and why?
Males because they only have 1 X-sex chromosome & girls have a 2nd X which if dominant can mask the disorder

31. 29. If a mother has a disorder, what is the likeliness her son will have it too?
100%-mother gives the son his only X & if she only has affected X’s-then he will have disorder

32. 30. If a daughter has a disorder, which parent(s) contributed the chromosome?
Both

33. Describe the 3 types of genetic screening and the method used to analyze them?
Blood tests
Amniocentesis-draw fluid from sac
Chorionic Villi Sampling-testing tissue from between uterus & placenta
Karyotyping-taking tests & arranging the chromosomes into homologous pairs by size & shape

34. 32. What is the benefit of pedigree charts?
To view heredity and characteristics

35. 33. What type of allele can a carrier have but not show the condition?
recessive

36. 34. What type of chromosomal disorder can males not be a recessive carrier for?
X linked