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Human Traits. Humans have 23 pairs of chromosomes (total of 46 . One pair of chromosomes is related to the sex of an individual , these chromosomes are called sex chromosomes. Autosomal or Sex Linked. Other 22 pairs of chromosomes are called autosomes (1-22). Surface Proteins.
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Human Traits • Humans have 23 pairs of chromosomes (total of 46. • One pair of chromosomes is related to the sex of an individual , these chromosomes are called sex chromosomes
Autosomal or Sex Linked • Other 22 pairs of chromosomes are called autosomes (1-22)
Surface Proteins Blood Types-what’s the difference?
Blood Donation Chart Type O can’t receive any other blood type, but can be given to any other blood type. Universal Donor is a type of blood that can be given to any other type because it has no antigens on its surface . Type AB can receive all other blood types because it has A and B antigens. Universal Receptor
Codominant: A condition in which both alleles are expressed phenotypically • Blood Typing: • A, B are codominant • O is recessive to A or B • IAIA, IBIB are pure breed/homozygous • ii is 0 • IAIB is the codominant heterozygous • IAi or IBiare the heterozygous pattern.
Codominant/Recessive Blood Typing IB i IA i
Sex Linked Traits • In humans, the sex of kid depends on the presence or absence of the Y chromosome XX = female XY = male
Sex Linked Traits • Genes that are located on the X or Y chromosome are called sex-linked genes. There are many more traits on the X • Traits determined by sex-linked genes are called sex-linked traits (c = colorblind, C = normal) Ex. Color blindness female Xc Xc male Xc Y
Sex Linked Traits • Most sex linked traits are recessive, this means both x chromosomes must have the gene in order for the trait to be expressed.
Inheritance of X-linked recessive traits • Hemophiliac female: Xh Xh • must inherit recessive alleles from both parents • Rare: 1 in 100,000,000 • Hemophiliac male: XhY • only inherit from mom (dad donates Y chromosome) • Much more common: 1 in 10,000
Sex Linked Traits • If only one x chromosome is present (in males)and has the sex linked gene, then the trait will be expressed • Sex-influenced traits are traits that have a different expression in males and females. • Examples of Sex-linked: • Color blindness, hemophila, muscular dystrophy • Examples of sex-influenced: • Male pattern baldness
Carriers • A carrier is a person that has the trait on only one chromosome and does not express the trait. • Only females can be carriers of sex linked traits. (C= normal, c= colorblind) Ex. Color blind carrier XC Xc
Sex Linked Punnett Squares • A colorblind male marries a normal female. What are the offspring genotypes and phenotypes? (C = normal, c = colorblind) Xc Y XC XC
Sex Linked Punnett Squares • A colorblind male marries a normal female. What are the offspring genotypes and phenotypes? (C = normal, c = colorblind) Xc Y XCXCXc XC Y XC XCXc XC Y
Sex Linked Punnett Squares • A normal male (not colorblind) marries a carrier. What are the offspring genotypes and phenotypes? XC Y XC Xc
Sex Linked Punnett Squares • A normal male (not colorblind) marries a carrier. What are the offspring genotypes and phenotypes? XC Y XC XC XC XC Y Xc Xc Xc Xc Y
Sex Linked Punnett Squares • A normal male (not colorblind) marries a colorblind female. What are the offspring genotypes and phenotypes? XC Y Xc Xc
Sex Linked Punnett Squares • A normal male (not colorblind) marries a colorblind female. What are the offspring genotypes and phenotypes? XC Y Xc XC Xc Xc Y Xc XC Xc Xc Y
Comparison to autosomal traits • Recessive autosomal traits require that all individuals (males and females) inherit two recessive copies in order to exhibit the recessive phenotype. • Inherit one recessive allele from mom and one from dad
Example: Cystic Fibrosis • A recessive trait whose gene is located on an autosome (a chromosome that is not a sex chromosome). • CFTR gene is responsible for making a protein that controls movement of salt and water into and out of cells • C: makes normal-functioning protein • c: makes disfunctional protein • Leads to thick, sticky mucus that damages lungs
Hemophilia • Hemophilia is characterized by uncontrolled bleeding • It is a sex linked disorder caused by errors in the DNA that codes for the proteins involved in clotting