LIFE 120 Lecture Notes - Lecture 13: Thomas Hunt Morgan, Frederick Griffith, Martha Chase
Document Summary
Concept 15. 4: alterations of chromosome number or structure cause some genetic disorders. Chromosomal alterations lead to miscarriages or developmental disorders. Nondisjunction: homologous chromosomes do not separate normally during meiosis, one gamete receives two/other no chromosome. Aneuploidy - results from nondisjunction: abnormal number of chromosomes in a zygote. Trisomy of ch 21 causes down syndrome. Nondisjunction and aneuploidy: occurs during meiosis i or meiosis ii with different results. 1 trisomic & 1 monosomic gamete if meiosis ii. Concept 15. 3: linked genes tend to be inherited together because they are located near each other on the same chromosome. Each chromosome has hundreds or thousands of genes (except the y chromosome) Genes located on the same chromosome that tend to be inherited together are called linked genes. Thomas hunt morgan did experiments with fruit flies to see how linkage affects inheritance of two characters. Morgan crossed flies that differed in traits of body color and wing size.
