GENE 500 Study Guide - Midterm Guide: Sister Chromatids, Dna Replication, Synapsis
Document Summary
Comparison of mitosis and meiosis: both somatic cells and pre-meiotic germ cells have two copies of each chromosome (2n), one maternal and one paternal. The resulting cells undergo a second division without intervening dna replication, so that one of the sister chromatids of each morphological type is apportioned to the daughter cells. In the second meiotic division, the alignment of chromatids and their equal segregation into daughter cells is the same as in mitotic division. The alignment of pairs of homologous chromosomes in metaphase i is random with respect to other chromosome pairs, resulting in a mix of paternally and maternally derived chromosomes in each daughter cell. All the offspring in the first (f1) generation are heterozygous. If the mutant allele is dominant, the f1 offspring will exhibit the mutant phenotype. If the mutant allele is recessive, the f1 offspring will exhibit the wild-type phenotype.
