A picture of chromosomes in ordered pairs Karyotype A picture of chromosomes in ordered pairs

Humans have 46 chromosomes. They have 23 pairs of chromosomes. Karyotype Humans have 46 chromosomes. They have 23 pairs of chromosomes.

Two chromosomes that determine an individual’s sex. Sex Chromosomes Two chromosomes that determine an individual’s sex.

Two X Chromosomes: Female X and Y Chromosomes: Male Sex Chromosomes Two X Chromosomes: Female X and Y Chromosomes: Male

Sex Chromosomes Egg cells: single X chromosome Sperm cells: half X and half Y chromosomes

Remaining chromosomes of an individual Autosomes Remaining chromosomes of an individual

Located on Chromosomes Genes Located on Chromosomes

Multiple genes used to determine blood type Blood Type Genes Multiple genes used to determine blood type

Rh stands for “rhesus monkey” Dominant: Rh+ Recessive: Rh- Rh blood group Rh stands for “rhesus monkey” Dominant: Rh+ Recessive: Rh-

ABO Blood Group ABO alleles produce specific antigens Antigens: trigger an immune response

Blood Group Genes Both ABO and Rh groups are mentioned at the same time Ex. AB- means AB blood type and Rh-

Takes two alleles to be expressed Recessive Alleles Takes two alleles to be expressed

Recessive Allele Disorders PKU Tay-Sachs disease

Only takes one allele to be expressed Dominant Allele Only takes one allele to be expressed

Dominant Allele Disorders Huntington’s disease Achondroplasia (Dwarfism)

Both alleles contribute to physical expression Codominant Alleles Both alleles contribute to physical expression

Codominant Allele Disorder Sickle Cell disease