18Curled Up Nose Roman Nose Traits governed by simple dominance(not an exhaustive list)Dominant RecessiveBrown Eyes Blue EyesCurled Up Nose Roman NoseClockwise Hair Whorl Counter-clockwise hair WhorlCan Roll Tongue Can't Roll TongueWidow's Peak No Widow's PeakFacial Dimples No Facial DimplesAble to taste PTC Unable to taste PTCEarlobe hangs Earlobe attaches at baseMid-digital hair No mid-digital hairNo hitchhiker's Hitchhiker's thumbthumbTip of pinkie bends Pinkie straightin
19Genetics Since Mendel Ch. 5 section 2 Are all traits inherited only by dominant or recessive alleles?
20INCOMPLETE DOMINANCEProduction of a phenotype,(physical trait), that is intermediate, (blended), between the two homozygous parents.WHITEREDPINK
22Multiple Alleles A trait that is controlled by more than two alleles. Examples is blood type which is controlled by three alleles, A, B, O which gives us four phenotypes: A, B, AB, or O.
23Polygenic Inheritance Poly means many.Polygenic inheritance is when many gene pairs act together to produce a trait.Examples for this inheritance would be eye color, height and skin color. This is why we might not have the same shade of color of eyes or skin as our parents have. Also this is why it is hard to predict height just based on our parents height. eyes
24Even though your traits are determined by your genes, environmental influences can alter how your trait is expressed.Examples:If you have a gene for skin cancer, you can limit your exposure to the sun and take care of your skin.If you have a gene for lung cancer, you can make sure you do not smoke and try to control your air quality.Himalayan rabbits have alleles for dark-colored fur. But this allele can only express itself at lower temperatures which are areas located away from the main body heat.
25Mutations Mutations are changes in genes. Some mutations are harmful some are helpful.Mutations in genes can occur when the DNA is copied and something goes wrong. Chemicals can also alter genes.Examples of things that can mutate genes are radioactive material and X-rays
26Chromosome DisordersOccur when mistakes in the process of meiosis results in an organism with too many or too few chromosomes.Examples:Down Syndrome- baby has 47 chromosomes instead of 46 chromsomes.
27Downs Syndromecharacteristic facial features, short stature; heart defectssusceptibility to respiratory disease, shorter lifespanprone to developing early Alzheimer's and leukemiaoften sexually underdeveloped and sterile, usually some degree of mental retardation.Down Syndrome is correlated with age of mother but can also be the result of nondisjunction of the father's chromosome 21.
28Patau syndrome (trisomy 13): serious eye, brain, circulatory defects as well as cleft palate. 1:5000 live births. Children rarely live more than a few months.
29Edward's syndrome (trisomy 18): almost every organ system affected 1:10,000 live births. Children with full Trisomy 18 generally do not live more than a few months.
30Too few chromsomesMonosomy X (Turner's syndrome): 1:5000 live births; the only viable monosomy in humans - women with Turner's have only 45 chromosomes!!! XO individuals are genetically female. Have short stature, normal intelligence and are sterile. (98% of these fetuses die before birth)
31Recessive Genetic Disorders When each parent has the recessive gene and their baby receives the recessive gene from both parents.Examples of this type of disorder:Cystic Fibrosis- affects for Caucasian AmericansCauses thick mucus in lungs and intestinal tractSickle Cell Anemia-affects more African AmericansCauses clogging of blood vessels, organ damage,kidney failureTay-Sachs- Buildup of lipids causes death byage 2-3.
32Sex-Determination Female chromosomes are XX Male Chromosomes are XY XX
33SEX LINKED DISORDERSAn allele inherited on a sex chromosome, X or Y is called a sex linked disorder.Males are more likely to have sex linked disorders than females. The reason for this is that for a male to have a disorder he only has to have the allele on one chromosome, XcY. In order for the female to have the disorder she has to have the allele on both her sex chromosomes, XcXc. If she has the allele only on one of her sex chromosomes she is considered to be a carrier, XcX and can pass it on to her children.
34XY Examples of sex linked disorders Color Blindness-is a recessive trait on the X chromosomeABXcYXYXcXXYXcXXcYXXXYXX cXXIn example A, a color blindMale has a child with a normalFemale. They will have a 50%Chance of having a normal maleBaby and a 50% chance of havingA female baby who is a carrier forColor blindness.In example B, a normal male has a child with a carrier female. They will have a 25% chance of having a female who is a carrier, 25% chance of having a male who is colorblind, 25% chance of having a normal female and 25% chance of having a normal male.
35Another example of a sex linked disorder is hemophilia Another example of a sex linked disorder is hemophilia. A person with this disorder do not make enough platelets in their blood that helps the blood to clot when they are cut.Pedigree Chart
36Why would you use a Pedigree Chart? A geneticist would study a pedigree chart of someone to predict the probability that a baby would be born with a specific trait.Breeders of animals or plants can study the pedigree of these organisms for desirable physical and ability traits.
37Genetic EngineeringIt is biological and chemical methods to change the arrangement of a gene’s DNA to improve crop production, produce large volumes of medicine, and change how cells perform their normal functions.Recombinant DNA-(helps with making insulin)Gene Therapy-(using a virus to deliver a normal allele to replace a defective allele; cystic fibrosis and cancers)