Presentation on theme: "ABO Blood Groups and Genetic Disorders"— Presentation transcript:
1 ABO Blood Groups and Genetic Disorders Human InheritanceABO Blood Groups and Genetic Disorders
2 Important VocabularySlide #21. Carrier: someone who is heterozygous for a trait2. Multiple alleles: traits that have more than 2 possible alleles; still only inherit 2 alleles3. Co-dominance: when two different alleles are present and BOTH alleles are expressed.4. Mutation: a change in an organism’s DNA; changes how a gene functionsa. leads to 2 or more alleles for a given trait
3 Variations in Alleles 1. Variations in traits arise from mutations Slide #3Variations in Alleles1. Variations in traits arise from mutations2. Many mutations produce genes that don’t function a. most of these mutations produce non-functioning proteinsb. non functioning proteins can cause lethal genetic defectsc. sometimes mutations produce proteins that have different functions
4 ABO Blood Groups 1. Multiple alleles Slide # 41. Multiple allelesa. 3 different alleles; IA, IB, & ib. 6 genotypes / 4 phenotypesIA IA or IA i = Type AIB IB or IB i = Type BIA IB = Type ABi i = Type O2. IA and IB are co-dominant; both are expressed if both are present
5 Guide to who can give and who can receive in donating blood Slide # 6Guide to who can give and who can receive in donating blood
6 Genetic Disorders are caused by defective genes. Defective genes arise from mutations in DNA.
7 Cystic Fibrosis 1. Mode of inheritance Slide # 71. Mode of inheritancea. recessive allele on chromosome # 72. Symptoms:a. thick mucus forms in lungs & digestive tractb. Affected people have trouble breathing; contract lung infections easilyc. Affected people live to be about 30 years old1 in 25 Caucasians in US are carriers1 in 2500 are affected
8 8 to 10% African Americans are carriers Sickle-Cell AnemiaSlide # 81. Mode of inheritancea. recessive allele on chromosome # 112. Symptomsa. blood cells become sickle shaped; don’t carry oxygenb. sickle shaped cells clog blood vessels & cause pain & swellingc. Affected persons live to be about 503. Carriers are resistant to malariaNormal blood cells live 120 daysSickle-shaped blood cells live days8 to 10% African Americans are carriers
9 Tay Sachs 1. Mode of Inheritance Slide # 9Tay Sachs1. Mode of Inheritancea. recessive allele on chromosome # 152. Symptomsa. Fatty substance builds up in nerve cells in brainb. Gradual paralysis & loss of nerve functionc. Affected children die by age 4 or 53. Carriers resistant to tuberculosis11% of Jewish population are carriersAlso common in French-Canadians & Cajuns
10 PKU 1. Mode of Inheritance a. recessive allele on chromosome # 12 Slide # 10PKU1. Mode of Inheritancea. recessive allele on chromosome # 122. Symptomsa. body does not break down phenylalanineb. high level of phenylalanine interferes with nervous system development; leads to mental retardationc. Easily treated by following strict dietd. all newborns tested for PKUFoods farthest away from the target must be avoided.
11 Huntington’s Disorder Slide # 111. Mode of inheritancea. dominant allele on chromosome # 42. Symptomsa. brain cells slowly break down; causes jerking muscles, slurred speech, difficulty swallowing, loss of balance, reasoning & memory loss, & eventually deathb. Symptoms usually begin at years of age
12 Sex-linked traits: Genes located on the sex chromosomes.
13 Important Vocabulary 1. Autosome: a regular body chromosome (# 1 - 22) Slide # 13Important Vocabulary1. Autosome: a regular body chromosome (# )2. Sex chromosome: chromosome that determines the sex of an individual; X & Ya. XX = femaleb. XY = malec. The sex chromosomes are # 23
14 Slide # 14Sex Linked Traits1. Sex-linked trait: A trait that is determined by a gene found on one of the sex chromosomes.2. Occur more often in males because males only receive one X chromosome (one copy of the gene).3. Fathers pass the X chromosome on to daughters only.4. Mothers pass an X chromosome on to sons and daughters.5. Females must receive 2 copies of the defective gene to show the trait.
15 Hemophilia 1. Mode of inheritance a. recessive allele on X chromosome Slide # 151. Mode of inheritancea. recessive allele on X chromosome2. Main Symptoma. blood fails to clot properlyb. may bleed internally – especially at the knees and elbowsHemophilia can be traced through a pedigree of the royal family.
16 Color-blindness 1. Mode of Inheritance Slide # 161. Mode of Inheritancea. recessive allele on X chromosome2. Symptomsa. inability to distinguish red and green colorsb. Normal life span