1. The Human Genome
Ch. 14

2. Human Chromosomes Karyotype = how chromosomes are arranged in pairs
Humans have 46 chromosomes or 23 pairs
The 23rd pair are the sex chromosomes
XY = male
XX = female
The other 22 pair are called autosomes

4. Human Traits
Pedigrees are a chart that shows the relationships within a family as it relates to a certain trait
Circle = female
Square = male

6. Autosomal Disorders Caused by Recessive alleles Dominant alleles
Cystic fibrosis
Dominant alleles
Achondroplasia
Codominant alleles
Sickle cell disease

7. Sex-linked Genes Colorblindness Hemophilia Duchene Muscular Dystrophy
Males have just 1 X chromosome – so all sex linked alleles are expressed in males even if they are recessive

8. Chromosomal Disorders
Nondisjunction = chromosomes don’t separate correctly
Down syndrome
3 copies of the 21st chromosome