31Ch 11.2 Complex Patterns of Inheritance Most traits are not simply dominant or recessive
32Incomplete Dominance Dominant & recessive traits appear to "blend" Ex. snapdragon flowersred x white = pinkRR rr Rr
33Incomplete Dominance B B BB BB B Bb Bb b A homozygous dominant black cat is crossed with a gray cat and black is incompletely dominant over white. What is the percentage of having a gray kitten?BBBBBBBBbBbb
34Incomplete DominanceA gray cat is crossed with another gray cat and black is incompletely dominant over white. Complete a Punnett square and tell me what is the genotypic and phenotypic ratio of that cross?Phenotypic ratio:Genotypic ratio:
35Codominance Two traits are both fully seen “Co”= together Ex. Roan Horses have both red & white hairs
36Codominance R W R RR RW RR RW R Both alleles should be Capital letters since one is not dominant over another.Cross: Roan Horse X Red HorseRWRRRRWRRRWR
37CodominanceIn humans, wavy hair (CS) results by the co-dominance pattern of curly hair (C) and straight hair (S). What are the possible results if a wavy-haired man and a straight-haired woman have children?List Genotypic and Phenotypic Ratios!
38Multiple Alleles Two or more alleles control the phenotype Ex. Human ABO blood groups
41Multiple AllelesA woman with type B (heterozygous) blood and a man with type AB blood are expecting a child. What are the possible blood types of the kids?
42Multiple AllelesA test was done to determine the biological father of a child. The child’s blood Type is B and the mother’s is Type A. Dude #1 has blood type O and dude # 2 has blood type AB. Which dude is the biological father?
43Polygenic Traits Traits that are controlled by multiple genes Ex. height, weight, hair color, skin color
44Skin ColorAt least 7 different Genes make up skin color!
57Studying InheritanceChromosomes # 1-22 are autosomes (body chromosomes)Chromosomes # 23 are the sex chromosomes.Looking at a karyotype you can see a chromosome mutation.
58______Chromosomal________ Abnormalities 1 infant in 200 newborns has a chromosomal abnormality28% of first trimester miscarriages have a chromosomal abnormalityAbnormalities in larger chromosomes don’t usually survive58
59____________________________: Change in the ______________ or CHROMOSOMAL MUTATIONS____________________________:Change in the ______________ or____________ of chromosomesstructurenumber
60Homologous chromosomes ________________ during MEIOSIS = _________________________One cell gets 2 copies ofthe chromosome theother cell gets none.fail to separateNONDISJUNCTION
66Turner syndrome ____ XO 1 in 5000 births Females have only one X chromosomeSmall sizeSlightly decreased intelligence35% have heart abnormalitiesHearing loss commonBroad chestReproductive organs don’t develop at pubertyCan’t have children66
68Klinefelter syndrome 1 in 1000 births Males have extra X chromosomes (Can be XXy, XXXy, or XXXXy)Average to slight decrease in intelligenceSmall testes/can’t have childrenUsually not discovered until puberty when don’t mature like peers68
69Obtaining Fetal Cells ~Making a Karyotype~ 1.Amniocentesis: sample of fluid around baby2.Chorionic Villus Sampling: sample of tissue from the placentaKaryotyping is a technique that can be used at any age. There are many ways to obtain a sample, however we will focus on two samples commonly used to obtain fetal samples. These fetal karyotypes can help determine chromosomal abnormalities before a baby is even born.AmniocentesisAmniocentesis is a process done to obtain a sample from an infant to be karotyped. It is normally considered in situations in which parents are at risk of having an infant with a genetic disorder. This includes situations of advanced maternal age, parents who have had a previous child with chromosomal problems and parents with the presence of a chromosomal translocation or rearrangement. More than 100 biochemical disorders can be tested through amniocentesis. (2)During this procedure, amniotic fluid, which surrounds the baby and provides protection, is taken from the amniotic sac by a long needle inserted into the woman’s abdomen. The body will make more amniotic fluid to replace the fluid removed in the procedure. (2)Chorionic Villus SamplingChorionic villus sampling is another procedure used to help determine genetic disorders present in the fetus. While this procedure is recommended for women with the same risk factors as in amniocentesis, it is more specialized than amniocentesis and can be done earlier in pregnancy (during about weeks of pregnancy). (2)During this procedure, a small, flexible catheter is inserted through the vagina or abdomen into the uterus and is guided by ultrasound images. A sample is taken from the chorionic villus, the fetal tissue that forms part of the placenta, by suction. (2)
78Create A Pedigree:One couple has a son and a daughter with normal pigmentation. Another couple has one son and two daughters with normal pigmentation. The daughter from the first couple has three children with the son of the second couple. Their son and one daughter have albinism; their other daughter has normal pigmentation.