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

Other 22 pairs of chromosomes are called autosomes (1-22)

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 I A I A, I B I B are pure breed/homozygous ii is 0 I A I B is the codominant heterozygous I A i or I B iare the heterozygous pattern.

Codominant/Recessive Blood Typing IAIA i IBIB i

In humans, the sex of kid depends on the presence or absence of the Y chromosome XX = female XY = male

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 X c X c male X c Y

Are you colorblind?

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: X h X h –must inherit recessive alleles from both parents –Rare: 1 in 100,000,000 Hemophiliac male: X h Y –only inherit from mom (dad donates Y chromosome) –Much more common: 1 in 10,000

A hemophilia carrier x a normal male

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

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 X C X c

A colorblind male marries a normal female. What are the offspring genotypes and phenotypes? (C = normal, c = colorblind) X c Y X C

A colorblind male marries a normal female. What are the offspring genotypes and phenotypes? (C = normal, c = colorblind) X c Y X C X C X c X C Y

A normal male (not colorblind) marries a carrier. What are the offspring genotypes and phenotypes? X C Y X C X c

A normal male (not colorblind) marries a carrier. What are the offspring genotypes and phenotypes? X C Y X C X C X C X C Y X c X c X c X c Y

A normal male (not colorblind) marries a colorblind female. What are the offspring genotypes and phenotypes? X C Y X c

A normal male (not colorblind) marries a colorblind female. What are the offspring genotypes and phenotypes? X C Y X c X C X c X c 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 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