Complex Genetics

1. Complex Genetics Packet 12

2. Vocabulary

3. Notes: Incomplete & Codominancepages 1-2

4. Notes: Incomplete Dominance & Codominance In Mendel’s principle of dominance, if an organism is heterozygous, the dominant allele will completely cover up the recessive allele. This is also known as ___________ _____________ • Example: In pea plants purple is completely dominant over white PP and Pp = purplepp = white Complete dominance

5. In most organisms, especially humans, a large number of traits are controlled by more complex forms of inheritance. The patterns of inheritance that we will look at include: • Incomplete Dominance • Codominance • Multiple Alleles • Polygenic Traits • Sex-linked Traits • Sex-Influenced Traits

6. inComplete dominance ______________ ______________-The dominant allele does not fully cover up a recessive allele… instead a heterozygote will have a new trait that is a mixture of the two alleles. Example: In carnations, incomplete dominance can be seen in flower color: • ________ flowers = (RR) • ________ flowers = (Rr) • ________ flowers = (rr) Red pink white

7. Rr Rr R r 1/4 REd 2/4 Pink 1/4 white 1/4 2/4 1/4 RR Rr R r Rr rr RR Rr R R 2/4 2/4 0/4 2/4 REd 2/4 Pink 0/4 white RR RR R r Rr Rr

8. Both Codominance - When two different alleles are ________ expressed at the same time (neither one is able to hide the other… neither is recessive). • Codominant alleles are written as capital letters with superscripts or subscripts (HR or B1). Since these traits are inherited from both parents, a genotype still contains _____ symbols two The allele for red hair (HR) is codominant with the allele for white hair (HW) in cattle. Cattle that have the genotypes HRHW are called roan because their hair is a mixture of red & white hairs.

9. HRHR x HWHW HR HR 0/4 4/4 0/4 0/4 red 4/4 Red & White 0/4 white HW HW HRHW HRHW HRHW HRHW HRHw x HrHW HR Hw HR Hw HRHr HRHW 1/4 hrhr 2/4 hrhw 1/4 hwhw 1/4 red 2/4 Red & White 1/4 white HRHW HwHW

10. Sickle Cell Anemia

11. Complete, Incomplete or Codominance? The gene for making hemoglobin, a protein on red blood cells has several different alleles. For normal hemoglobin we use the allele HA, for the abnormal hemoglobin we use the HSallele. Having a double dose (2 copies) of the abnormal allele causes a disease called sickle cell anemia. • HA HA= ________________________ individuals (unchanged red blood cells) • HA HS = Sickle cell ______________, for the most part are normal… but can have some issues when oxygen levels are low (strangely enough, these individuals are resistant to malaria). • HS HS = Those with ____ copies of the sickle allele (homozygous)… will suffer from sickle cell anemia. Normal / Healthy carriers 2

12. 1. If two sickle cell carriers have 4 kids, how many would we expect to suffer from the disease? Show your work. HaHsHaHs HA HS 1/4 HaHa 2/4HaHs 1/4 HsHs Ha Hs HaHa HaHs 1/4 healthy 2/4 Carrier 1/4 sickle Cell (sufferer) HaHs HsHs

14. Understanding Different ways that alleles interactpage 3

18. Practice Problems: Incomplete & Codominancepages 3 & 4

19. Hh Straight curly hh Hh h h 0/4 HH 2/4 Hh 2/4 hh 0/4 Straight 2/4 Wavy 2/4 Curly H h Hh Hh hh hh 0:2:2 0:2:2 2/4 or 50%

20. Ff White Cream Yellow FF ff Ff Ff F f 1/4 White 2/4 Cream 1/4 Yellow 1/4 FF 2/4 Ff 1/4 ff F f FF Ff Ff ff 1:2:1 1:2:1 1/4 or 25%

21. Tan Chestnut Palomino HCHP HCHP HC HP 1/4 Chestnut 2/4 Palomino 1/4 Tan 1/4 HCHc 2/4 HCHP 1/4 HpHP HC HP HCHc HCHp HCHp HpHp 2/4 or 50% 1:2:1 1:2:1

22. Black FbFw FwFw White FbFb Checkered FbFb FbFw FbFw 2/4 Black 2/4 Checkered 0/4 White 2/4 Fbfb 2/4 Fbfw 0/4 Fwfw Fb Fb FbFb FbFw FbFw FbFb 2:2:0 2:2:0 0%

23. Notes: Multiple Allelespages 5 & 6

24. Notes: Multiple Alleles (Blood Typing) 3 Multiple Allelesmeans that a single gene that has _____ or more alleles (or forms of a gene). In other words, not just one dominant and one recessive allele (i.e. R and r). • In humans, there are three different alleles that determine the basic blood type. IA , IB and i. • An IA allele, makes your red blood cells be made with A antigens (ID tags) on them. • An IBallele, makes your red blood cells be made with B antigens (ID tags) on them. • The i allele is missing instructions for either antigen (no ID tag is made).

25. 2 Your blood type is determined by which _____ alleles you inherit from your mom and your dad. These alleles tell your body what type of antigen to produce on your red blood cells (RBCs). • Antigens are molecules on the blood cells that are recognized by the immune system. O A B AB A antigens & B antigens No antigens A antigens B antigens IAIA IBIB IAIB ii IAi IBi

26. For blood type family “A” Blood type family “B” Blood type family “O” Blood Type

27. transfusion Sometimes when individuals lose too much blood due to a trauma or surgery, other blood can be given to them. This is called a _______________. • Because of the ________________on the red blood cells, it is extremely important that the correct blood type be given. • If the wrong blood is transfused, the immune system responds by attacking the new red blood cells. Antigens Antibodies • ________________ attach to the foreign blood cells which causes the blood to clump up. As a result, the individual may go into shock and possibly die.

28. A, B, AB & O only O A & O B & O A, B, AB & O A & AB B & AB only AB Type O • The Universal Donoris ________________. • The Universal Recipientis ________________. Type AB

29. Practice: Only the genotypes & phenotypes that appear in the punnett squares need to be written. 1. A man with type O blood marries a woman with type AB blood, what are the possible blood types of their children? ii Ia ib IAi 2/4 Iai 2/4 IBi IAi IBi IBi 2/4 Type A 2/4 Type B

30. 2. A child with type O blood finds out that their father has Type A blood and their mother has Type B blood. Based upon this information, do you think that the child must not be their biological child? Why or why not? Show your work!!! A type A parent and a Type B parent can have a Type O child if both parents are heterozygous. IA i IAIB IBi IB i IAi ii

31. It’s not just about A’s and B’s on your red blood cells. A second gene also controls if you have another antigen called _____________ on your red blood cells. This trait is not caused by multiple alleles like the ABO blood groups, rather it is influence by simple complete dominance. • Rh____________allele causes people to produce the Rh antigen on their blood cells. (Dominant) • Rh________________allele DOES NOT provide the instructions for making a Rh antigen on the blood cells. (Recessive) Rh factor Positive negative

33. Rh+ Rh+ Rh- • A person that is AB+ has ___(#) antigens on their blood cells (___________________). 3 A, B and Rh+

35. Practice Problems: Multiple Allelespages 7 & 8

40. Notes: Polygenic Traitspage 9

41. Notes: Polygenic Traits Polygenic Traits are controlled by the interaction of more than one gene. These traits tend to show great degrees of variation.

42. Skin color is caused by at least 3 different genes that code for the production of pigment. The more dominant genes that you have, the more pigment is produced (and therefore the darker your skin). • With 3 genes, there are ____ possible phenotypes. • What would be the expected skin tone of children if one parent has the darkest skin tone and the other parent has the lightest skin tone? Parents = AA BB CC x aa bb cc Expected genotype of the children would be __________ with __________skin tone 7 Aa Bb Cc medium

43. If two parents have a medium skin tone (AaBbCc), their children could have: _____________________ __________________________________________ • By looking at the graph, we can see that it is most likely that their kids will have ___________ skin tone. A wide variety of skin colors – light to dark medium

44. In humans, other examples of polygenic traits:

45. Notes: Sex-Linked Traitspage 10

46. Sex determination Thomas Hunt Morgan While studying fruit flies (≈1910) ________ ______ ________ discovered that there were chromosomes that were different in males and females. • He named them ____ _______________ since they determine a person’s gender. Sex chromosomes

47. X Y XX XY • In humans, the sex chromosomes are named the __and __chromosomes. • Both genders have two sex chromosomes: • Female have ______ and males have ______ (the Y is the smaller of the two sex chromosomes).

48. Sex-Linked Traits 1. Genes which are located on the sex chromosomes are said to be sex-______________. • Not all genes on the sex chromosomes control gender (i.e. color-blindness & hemophilia) 2. Most sex-linked traits occur more frequently in ________ because they have only ___ X chromosome (males cannot be carriers for sex-linked traits, if they inherit the gene for a sex-linked disorder they will show it). linked males 1

49. colorblindness __________________ (Xn) is a very common sex-linked trait and is recessive to normal vision (XN). More males have this disorder than females.

50. __________________ (Xn) is a very common sex-linked trait and is recessive to normal vision (XN). More males have this disorder than females.