1. Test Monday 1/31

2.  Chromosome: DNA that has been tightly wound together, individuals genetic code  Gene: segment on a chromosome that code for a trait  Allele: distinct form of a gene

3.  When three or more alleles are formed in a population. These genes have multiple alleles  EX: Blood Type– A, AB, B, O

4.  O is recessive  A and B are both dominant (codominant)

5. How common are the blood types? Transfusions: O+A+B+AB+O-A-B-AB- 37.4%35.7%8.5%3.4%6.6%6.3%1.5%0.6% Phenotype (Blood Type Genotype Antigen on Red Blood Cell Safe Transfusions To From

6.  Cross a female who is heterozygous with A blood and a male who is heterozygous with B blood

7.  When both alleles are expressed (seen) fully  Happens in the heterozygous (Bb, Hh)  EX: speckled chickens and Blood Type

8.  In chickens: BB=black Bb=speckled (codominant) bb=white Work a punnett square crossing a black rooster with a white hen

9.  What are the genotypes from the cross?  What are the phenotypes from the cross?  Phenotype is not read as a dominant look! In codominant traits both alleles are expressed hence the speckled look

10. X

11. X X

12.  When two different alleles for the same trait COMBINE, but neither “wins” expression over the other  Shows a BLENDED look phenotype in the heterozygous (Bb, Hh)

13.  Snapdragons inherit color by incomplete dominance RR=red rr=white Rr= PINK (blended look) Cross 2 heterozygous snapdragons

14.  What are the genotypes from the cross?  What are the phenotypes from the cross?  Phenotype is not read as a dominant look! In incomplete dominant traits the allele is expressed as BLENDED

15. X X

16.  Alleles are BLENDED—black rabbit crossed with a white rabbit makes a gray rabbit X X

17.  Traits which are carried on the X chromosome  More common in MALES  EX: colorblindness, hemophelias

18.  Colorblindness is a recessive trait PhenotypeGenotype Female normalXCXCXCXC Female carrierXCXcXCXc Female colorblindXcXcXcXc Male normalXCYXCY Male colorblindXcYXcY

19.  Cross a female carrier with a normal male  What are the genotypes and phenotypes?