2. OTHER PATTERNS OF INHERITANCE OF TRAITS

3. Human Genetics Not only do we as humans have some traits that are dominant over other traits (recessive) but we have other patterns in which we inherit traits from our parents. For example: Sex-linked Inheritance, Polygentics Inheritance, Multiple Allele Inheritance, Incomplete Dominance and Co-Dominance.

4. SEX-LINKED TRAITS Traits determined by a gene on the SEX chromosome (usually the X chromosome) Examples: Colorblindness, Hemophilia, Muscular Dystrophy Colorblindness: is when someone sees certain colors differently. The most common is Red-Green Colorblindness. Hemophilia : is when someone lacks platelets (the clotting agent) in their blood. Muscular Dystrophy : is when a group of muscles weakens the musculoskeletal system which affects movement.

5. Information regarding Sex-linked Traits: Females must receive 2 affected X chromosomes in order to express the trait. Females with only 1 affected X chromosome are carriers. Males that receive 1 affected X chromosome from their mother expresses the trait. REMEMBER: XX  female and XY  male

6. SEX-LINKED TRAITS PUNNETT SQUARE PRACTICE Cross a colorblind mother with a father who has normal vision: Key: XXc = colorblind mother XY Key: XcXc = colorblind mother XY = normal vision father Cross Statement: XcXc (x) XY Give the genotypic and phenotypic ratios. Xc Xc Mom X Y Dad Genotype ratio: Phenotype ratio: Answers on next slide….

7. SEX-LINKED TRAITS PUNNETT SQUARE ANSWERS Cross a colorblind mother with a father who has normal vision: Key: XXc = colorblind mother XY Key: XcXc = colorblind mother XY = normal vision father Cross Statement: XcXc (x) XY Give the genotypic and phenotypic ratios. Xc Xc Mom X Y Dad XcX XcY Genotype ratio: 2:4 XcX and 2:4 XcY Phenotype ratio: 2:4 carrier females and 2:4 colorblind males

8. MORE SEX-LINKED TRAITS PRACTICE: Cross a mom who is a carrier of hemophilia with a dad who has hemophilia: Remember to use XX for female and XY for male. Cross Statement: XhX x XhY Xh X Xh Y Genotype %: Phenotype %: Answers on the next slide…..

9. SEX-LINKED TRAITS PUNNET SQUARE ANSWERS: Cross a mom who is a carrier of hemophilia with a dad who has hemophilia: Remember to use XX for female and XY for male. Cross Statement: XhX x XhY Genotype %: 25% XhXh and 25% XXh 25% XhY and 25% XY Phenotype %: 25% hemophiliac females 25% carrier females 25% hemophiliac males 25% normal blooded males Xh X Xh Y XhXh XY XhY XXh

10. Many of the traits that we inherit are called Polygenic Traits which means that many alleles control expression of the trait. Poly means many! Examples are skin color, hair color, eye color etc.

11. Some traits are controlled by Multiple Alleles such as Blood Group. There are 3 possible alleles for Blood Type: A, B and O

12. BLOOD TYPE PUNNETT SQUARE PRACTICE: Cross a female who is Type AA with a male who is Type O (ii): Give the genotypic and phenotypic ratios. Key: AA = mother ii Key: AA = mother ii = father Cross Statement: AA x ii A A iiii Show the Genotypic Ratio and the Phenotypic Ratio. Answers on next slide…..

13. A A iiii Ai BLOOD TYPE PUNNETT SQUARE ANSWERS: Cross a female who is Type AA with a male who is Type O (ii): Give the genotypic and phenotypic ratios. Key: AA = mother ii Key: AA = mother ii = father Cross Statement: AA x ii Genotypic ratio: 4:4 Ai Phenotypic ratio: 4:4 Type A Blood

14. Some traits don’t have complete dominance over other traits. We call this Incomplete Dominance. This means neither allele has “complete” dominance over the other; heterozygous phenotype is a blend of the 2 homozygous phenotypes. An example of this is in flowers known as Snapdragons! Red Colored Snapdragons = RR genotype White Colored Snapdragons = WW genotype When combined they create……. Pink Colored Snapdragons = RW genotype

15. INCOMPLETE DOMINANCE P.S. PRACTICE: White (WW) snapdragon Cross a red (RR) snapdragon with a White (WW) snapdragon. Give the genotypic and phenotypic ratios. Key: R = red flower Key: R = red flower W = white flower Cross: RR x WW R R WWWW Give the Genotypic and Phenotypic % of the cross: Answers on next slide….

16. R RWW RW INCOMPLETE DOMINANCE P.S. ANSWERS: White (WW) snapdragon Cross a red (RR) snapdragon with a White (WW) snapdragon. Give the genotypic and phenotypic ratios. Key: R = red flower Key: R = red flower W = white flower Cross: RR x WW Genotype %: 100% RW Phenotype %: 100 % Pink Snapdragons

17. Some traits “share” dominance and this is called Co-Dominance. This means that both alleles share dominance and both traits are expressed if present. For example, in certain birds this could happen: X= BB = Black Feathers x WW = White Feathers yields BW = Both Black and White Feathers

18. Co-Dominance Punnett Square Practice: Cross an all black feathered rooster with an all white feathered hen. Cross Statement: BB x WW B B WWWW Remember to show genotype and phenotype % of this cross. Answers on next slide…..

19. Co-Dominance Punnett Square Answers: Cross an all black feathered rooster with an all white feathered hen. Cross Statement: BB x WW B B WWWW Genotype %: 100% BW Phenotype %: 100% Black and White Feathers BW

20. There are other methods of finding inheritance patterns of traits. One way is through a Pedigree. 1.A Pedigree is a chart that traces the inheritance of a particular trait through several generations. 2. One GOAL of using a pedigree chart is to figure out who are carriers of the trait, because this information is typically unknown. a. Carrier : someone who is heterozygous for a trait.

21. Couple with children (offspring) SYMBOLS USED TO CONSTRUCT A PEDIGREE Affected traits are shown by using Carrier of an affected trait is shown by using a half-shaded

22. When showing many generations you must use: Roman Numerals placed to the left to represent each generation ( I,II, IV ) When showing Birth Order you must use: Numbers are used to indicate the birth order (1,2,3,4….) with oldest children listed to the left descending to the right for the youngest children. I II III 1 3 2

23. 1. Pedigrees are used to find out: a. who are carriers of the disorder b. the probability of having a future child with the disorder. 2. To begin to interpret a pedigree, first determine if the disorder a. is Autosomal dominant b. is Autosomal recessive c. is Sex-linked (carried on the X chromosome) STEPS USED TO DESIGN OR INTERPRET A PEDIGREE

24. First ask: Is it a Sex-linked Disorder or Autosomal Disorder? 1.If there is a much larger number of males than females who are affected then the disorder is Sex-linked. 2. If there is a 50/50 ratio between males and females who are affected then the disorder is autosomal. STEPS USED TO DESIGN OR INTERPRET A PEDIGREE

25. 3. If it is an autosomal disorder then ask: Is it dominant or recessive? 4. If two parents do not show the trait and their children do show it, then it is an autosomal recessive disorder - (parents are carriers or heterozygous) 5. If the disorder is autosomal dominant, then at least one of the parents must show the disorder. STEPS USED TO DESIGN OR INTERPRET A PEDIGREE

26. Pedigree Practice: Does this pedigree show a Sex-linked or Autosomal disorder? Answer: Sex-Linked disorder much larger number of males are affected

27. Does this pedigree show a Sex-linked or Autosomal disorder? Answer: Autosomal disorder 50/50 ratio between males and females

28. Does this pedigree show a Sex-linked or Autosomal disorder? Answer: Autosomal dominant disorder At least one parent of the affected children show the disorder

29. Other methods we can use to see the inheritance of genetic traits is called a Karyotype: A set of photographs (pictures) of your chromosomes grouped in order of pairs that tell us the gender of the organism and if there are any chromosomal abnormalities.

30. The last two chromosomes inherited from your parents are the sex chromosomes (XX or XY) which determine an individual’s sex. The first 44 chromosomes (1 – 22) are called autosomes.

31. At least 1 (X) chromosome MUST be present for survival The presence OR absence of the (Y) chromosome determines sex of offspring

32. Most karyotypes are normal but sometimes things can go wrong such as Nondisjunction. Nondisjunction is when homologous chromosomes fail to separate during Meiosis which results in an abnormal offspring (baby). There are three types of Nondisjunction : Monosomy – means there is only 1 copy of the chromosome. Trisomy – means there are 3 copies of the chromosome. Polyploidy – means there are multiple copies of chromosomes.

33. Turner’s Syndrome: 45XO 18

34. Klinefelter’s Syndrome: 47XXY

35. Down’s Syndrome: Trisomy 21

36. BIOTECHNOLOGY

37. Biotechnology is the use of living systems and organisms to develop or make useful products. It can also be any technological application such as artificial selection, genetic engineering, DNA fingerprinting and cloning that uses biological systems and living organisms to make or modify products or processes for specific use.

38. ARTIFICIAL SELECTION Earliest form of biotechnology that has been used in plants and animals. Its purpose is to produce desired traits There are 2 types of artificial selection: 1. inbreeding 2. outbreeding (also known as hybridization)

39. INBREEDING Cross organisms with similar genotypes Purpose: Maintain desirable traits in the same line of organisms Risks: Can cause undesirable recessive (rr) traits to be expressed (such as deafness, blindness, joint deformations)

40. OUTBREEDING Cross organisms from different species (genotypes) This is also known as “Hybridization”. It usually causes sterility but can also be used to conserve endangered species Florida Panther X Texas Cougars

41. Increases strength and vigor (Examples: mule, liger) Donkey (x) female horse Male lion (x) female tiger

42. GENETIC ENGINEERING Technique(s) used to identify or change genes at the molecular level. Many uses such as: determining paternity, identifying a carrier of a particular gene for a particular disorder, etc. One technique is Gel Electrophoresis used to make a pattern called a “DNA Fingerprint”.

43. Restriction Enzymes : cut genes out of a sample of DNA. The DNA fragment is then put into a chromosome of another organism. –“fish berries”- uses a trout gene to prevent strawberries from freezing

44. Gene Splicing: a process used to take certain genes from one organism and insert them into another. video

45. DNA FINGERPRINTING: Separate DNA fragments based on size through a gel an analysis of sections of DNA that have little or no known function in order to identify one individual from another. Example used in a paternity suit: lane 1 = mother lane 2 = child lane 3 = putative (="possible") father #1 lane 4 = putative father #2

46. DNA can be tagged / labeled with radioactive or fluorescent particles to better visualize the DNA fragments on a gel or genes on a chromosome

47. Cloning -The creation of an organism that is an exact genetic copy of another. This means that every single bit of DNA is the same between the two (like identical twins).

48. Genetically Modified Foods (GMO) Also known as Transgenic Plants, foods that have been genetically engineered for faster growth, resistance to pathogen and production of extra nutrients. Golden Rice- Produces more Vitamin A Strawberries- contain a gene from flounder to make them resist freezing Bt Corn- has a gene from bacteria to make it insect resistant Seedless Grapes- remove the gene for making seeds Bt