Genetics 3301

Chapter 3: Chromosome Theory

Evidence that chromosomes are the genetic material:

∑ Heteromorphic chromosome pairs and random assortment (3-2); Extra chromosomes and phenotypic differences (3-3); XY inheritance in Drosophila (3-5); WZ inheritance in chickens and moths (3-6); Genetic symbols in Drosophila; nondisjunction and aberrant segregation (3-7).

Characteristics of chromosomes:

Ä Number and size (T3-2; T3-3); centromere position; telomeres (3-16); heterochromatin and euchromatin; arrangement and size of genes on chromosomes (3-13, T3-1); giemsa banding patterns (3-17); polytene chromosomes (3-18); chromosome landmark summary (3-19).

Chromatin structure:

∑ One DNA molecule; histones and nucleosomes (3-20); packaging of DNA into a chromosome (3-38); scaffold, loops, SARs and topoisomerase II.

Mitosis and meiosis:

Ä Stages of mitosis (3-23); chromosome behavior during mitosis (3-24, 3-28); chromosome behavior during meiosis (3-24, 3-29); association of chromosomes and the spindle (3-26, 3-27); gene segregation and chromosome behavior during mitosis in diploids (3-31, 3-35); gene segregation and chromosome behavior during mitosis in haploids (3-31, 3-35); gene segregation and chromosome behavior during meiosis (3-35); Alternation of generations (3-33); meiotic segregation in Neurospora (3-37).

Key terms: Know all of these except bivalent, cpDNA, cytohet and dyads.

Problems: 5, 7, 10, 14, 18, 19, 25, 30.