EQ: How are genes responsible for the variety of organisms that exist? Non-Mendel Genetics (Day 2) EQ: How are genes responsible for the variety of organisms that exist?

Autosomes All chromosomes other than sex chromosomes Pairs 1-22 Contain all traits other than an organism’s sex Each autosome contains two copies of each gene (each parent)

Sex chromosomes Chromosomes that determine an organism’s sex Female = XX Male = XY

SeX-linked Traits Sex-linked traits- A trait associated with a gene that is carried only by the sex chromosomes (X chromosome)   The X chromosome is larger and carries more genes than the Y chromosome Sex-linked inheritance is related to the gender of the individual Examples: Red-green Color blindness Male Pattern Baldness Hemophilia Duchenne Muscular Dystrophy

Inheritance of sex chromosomes An example of an X-linked trait is hemophilia in humans.  Hemophilia is an X-linked recessive disorder, and is a condition in which the blood does not clot normally

Sex-linked Inheritance Alleles are attached to the X-Chromosome Females = XX Males = XY What is the chance of having a son? 50% (XY) What is the chance of having an affected child? 25% (XhY) What is the chance of having an affected son? 50% (XhY)

Expression in Males Males are more likely to be affected with sex-linked traits and recessive diseases Male: XY All sex-linked genes are expressed in males because there is only one allele

Expression in Females Similar to autosomal expression (law of dominance) Females = XX A female has two alleles because each X chromosomes carries an allele What are the three possible allele combinations? HH, Hh, hh FEMALES CAN BE CARRIERS*

Practice – left side If mom is a carrier for colorblindness and dad has normal vision, can they have a colorblind child?  If so how? Mom= ______Dad=______ Offspring=______ Your turn: If mom is normal vision female and dad is a normal vision male, can they have a colorblind child?  If not why? Mom=______Dad=_______Offspring=______ What are the genotypes of the parents that have a colorblind daughter? C = Normal vision c = colorblindness Normal Mother                  XCXC Normal Mother (carrier)    XCXc Colorblind Mother      XcXc Normal Dad                     XCY Colorblind Dad         XcY XCXc XCY XcY

How many people have a form of color deficiency? Color Test Discussion How many people have a form of color deficiency? How many males? How many females? Color blindness is a sex-linked trait, can any possible conclusions be drawn from this data?

Multiple alleles Genes with three or more alleles that code for a trait Only two alleles can be expressed as a phenotype Results in a variety of genotypes and phenotypes Ex. Blood alleles: A, B, O A and B are both Dominant O is recessive The i in each represents the antigen which allows us to test for blood types Recall: when have we talked about antigens? foreign substance which induces an immune response in the body, especially the production of antibodies

Multiple alleles IAIB IBi IAi i Genotype(s) Phenotype ii OO O IAIA, IAi AA, AO A IBIB, IBi BB, BO B IAIB AB  AB Multiple alleles If a heterozygous type A and a heterozygous type B mate, what are the possible genotypes and phenotypes of the offspring? Genotype: 1 heterozygous codominant (AB) 1 heterozygous A (AO) 1 heterozygous B (BO) 1 homozygous recessive (OO) Phenotype: 1 with AB blood type 1 with A blood type 1 with B blood type 1 with O blood type IA i IAIB IBi IAi i i IB i

Blood Types- What type of blood can be mixed during transfusions? When someone takes the blood of another person (during surgery, or after an accident) it is called a transfusion. If two different blood types are mixed together during a transfusion, the blood cells may begin to clump together due to the body rejecting the antigens in the blood vessels, possibly causing death. Therefore, it is important that blood types be matched before blood transfusions take place. To determine which transfusions are safe and which are not, think of blood types as different colors. If a color can receive another color without a color change, it is a safe transfusion. No Color Change = If a color changes when you add the other color to it, it is an unsafe transfusion. Color Change = Make sure to look for a color change, not just the color getting lighter or darker.

Blood Typing Lab Remember: Color Change = No color change = (lighter/darker color change) C- level 2 H- use your lab group and instructions, then raise a hand and wait for Ms Beck A- complete the blood typing lab to see which transfusion are safe M- remain at your assigned table with your group P- work with your group to determine which transfusion would be safe and complete your own lab data sheet and answer corresponding questions Success!

Exit ticket Close your notebook and Clear your desk!