BSC 315 Study Guide - Midterm Guide: Karyotype, Prophase, Sister Chromatids

• School: University of Alabama
• Department: Biological Sciences
• Course: BSC 315
• Professor: Edwin Stephenson

Document Summary

Phenotype- appearance, form, physiological state (eg yellow/green peas) Understanding that physical appearance is inherent to individual is ancient. Each individual has two copies of every gene. For gene a w/ two alleles, a & a: three possible genotypes: aa, aa, aa. Strict dominance/recessiveness- heterozygotes have the same phenotype as one of the homozygotes (eg aa has the same phenotype as aa) The a allele is dominant; the a allele is recessive. Genotype:phenotype relationships recognized about 150 years ago by gregor mendel. Austrian monk; published studies on pea genetics in 1866. Pure-breeding- strain that produces the same phenotype generation after generation. In a cross between two pure-breeding strains, all progeny have one of the two phenotypes. When the progeny are self-crossed, both phenotypes are present in the second generation in a 3:1 ratio. Self-cross- self-mating, or cross to a genetically-identical individual. Peas have 2 copies of each gene (diploid)