Non-Mendelian Genetics PDF

Non- Mendelian Genetics Prayer  Non- Mendelian Genetics Lesson Objectives: Describe the location of genes in chromosomes. Explain the different patterns of non-Mendelian inheritance State that some phenotypes are dictated by multiple genes Lesson Objectives: Dif...

Non- Mendelian Genetics Prayer  Non- Mendelian Genetics Lesson Objectives: Describe the location of genes in chromosomes. Explain the different patterns of non-Mendelian inheritance State that some phenotypes are dictated by multiple genes Lesson Objectives: Differentiate genotype and phenotype. Determine the genotype and the gametes of parents. Determine the percentage of the probability of genotype and phenotype of offspring. Color Test! Let’s Check your eyesight! Are you colorblind? Let’s check your eyesight using this simple test called Ishihara color plates test. Color Test! Let’s Check your eyesight! Are you colorblind? Let’s check your eyesight using this simple test called Ishihara color plates test. Color Test! Let’s Check your eyesight! Are you colorblind? Let’s check your eyesight using this simple test called Ishihara color plates test. Color Test! Let’s Check your eyesight! Are you colorblind? Let’s check your eyesight using this simple test called Ishihara color plates test. Color Test! Let’s Check your eyesight! Are you colorblind? Let’s check your eyesight using this simple test called Ishihara color plates test. Color Test! Let’s Check your eyesight! Are you colorblind? Let’s check your eyesight using this simple test called Ishihara color plates test. Color Test! Let’s Check your eyesight! Are you colorblind? Let’s check your eyesight using this simple test called Ishihara color plates test.  RECALL!! Mendelian Genetics: One allele is dominant over the other because the dominant allele can “mask” the recessive allele. Dominant and Recessive Alleles Example: purple-colored flower (A) is dominant over white- colored flower (a)  RECALL!! Genotype and Phenotype Genotype: AA, Aa, aa Phenotype: purple or white Homozygous and Heterozygous Homozygous: AA, aa Heterozygous: Aa  RECALL!! Allele Allele, is any one of two or more genes that may occur alternatively at a given site (locus) on a chromosome. Alleles may occur in pairs, or there may be multiple alleles affecting the expression (phenotype) of a particular trait.  REVIEW PROBLEM: In pea plants, purple flowers (A) are dominant over white flowers (a). Show the cross between two heterozygous plants  REVIEW PROBLEM: In pea plants, purple flowers (A) are dominant over white flowers (a). Show the cross between two heterozygous plants Aa x Aa A a A a A a AA Aa GR: 1:2:1 A purple purple PR: 3:1 a Aa aa purple white  NON-MENDELIAN GENETICS Incomplete Dominance Codominance Multiple Alleles Sex-Linked Traits Incomplete Dominance A third (new) phenotype appears in the heterozygous conditions as a blend of the dominant and recessive phenotypes. Ex: Red flower (RR), White flower (rr), Pink flower (Rr)  SAMPLE PROBLEM: Show the cross between a pink and white flower.  SAMPLE PROBLEM: Show the cross between a pink and white flower. rr- white, Rr- pink Rr x rr R r R r r r Rr rr GR: 1:1 r pink white PR: 1:1 r Rr rr pink white  CODOMINANCE This happens in the heterozygous condition, both alleles are expressed equally with NO blending Represented by two different capital letters  SAMPLE PROBLEM: In shorthorn cattle, when a red bull (RR) is crossed with a white cow (WW), all the offspring are roan—a spotted, red and white or milky red color. What offspring are expected from mating a roan bull and a roan cow? Show the Punnett Square.  SOLUTION: R- red, W- white, RW- roan RW X RW R W R W R W RR RW R red roan GR: 1:2:1 PR: 1:2:1 W RW WW roan white  OTHER EXAMPLES Speckled Chickens: BB- Black feathers WW- White feathers BW- Black and white speckled feathers  Multiple Alleles The existence of more than two alleles for a gene Ex: Blood types consist of two dominant and one recessive allele option. Allele A and B are dominant over allele O (i)  Multiple Alleles Rules for Blood Types: A and B are co-dominant (Both show) AA or I^A I^A= Type A BB or I^B I^B= Type B AB or I^A I^B= Type AB Multiple Alleles Multiple Alleles  SAMPLE PROBLEM: Show the cross between a mother who has type O blood and a father who has type AB blood  SOLUTION: i- Type O, AB- Type AB ii X AB i i i i A B Ai Ai A type A type A GR: 1:1 PR: 1:1 B Bi Bi type B type B  SAMPLE PROBLEM: A woman with type A blood is claiming that a man with a type AB blood is the father of her child with type B. Could the man be the father?  SOLUTION: Ai/AA- Type A, AB- Type AB Ai X AB A i A i A B AA Ai GR: 1:1:1:1 A type A type A PR: 1:2:1 B AB Bi Yes. It is possible. type AB type B  SEX-LINKED TRAITS Gene is attached to the chromosome only Men have XY chromosomes while women have XX chromosomes  SEX-LINKED TRAITS There is no second X chromosome in males to “mask” a recessive gene. If they get an X with the disorder (regardless if it's dominant or recessive), they have it. Females must inherit both defective X from both parents  SEX-LINKED TRAITS A: 29, B: 45, C: none, D: 26- normal vision A: 70, B: none, C: 5, D: none- red-green color blind A: 70, B: none, C: 5, D: 6- red color blind A: 70, B: none, C: 5, D:2- green color blind  SAMPLE PROBLEM: Red-green color blindness (b) is a recessive sex-linked trait. A colorblind male marries a normal female. Their daughter is colorblind. Determine the Punnet square for this cross.  SOLUTION: B- normal, b-colorblind X^bY X X^BX^B X^B X^b X^b Y X^B X^b X^BX^b X^bX^b X^b F, normal F, cb GR: 1:1:1:1 PR: 1:1:1:1 Y X^BY X^bY M, normal M, cb  SAMPLE PROBLEM: A colorblind woman marries a man with normal vision. She is pregnant. What is the chance that her child will be (a) a girl with normal vision? (b) a colorblind girl? (c) a boy with normal vision? (d) a colorblind boy?  SOLUTION: B- normal, b-colorblind X^BY X X^bX^b X^b X^b X^B Y X^b X^b X^BX^b X^BX^b X^B F, normal F, cb GR: 2:2 or 1:1 PR: 2:2 or 1:1 Y X^bY X^bY M, cb M, cb Thank you!