ANT 205 Lecture Notes - Lecture 4: Gregor Mendel, Pea, Allosome
Document Summary
Heredity: the genetic transmission of traits from parent to offspring. Concept used long before it was understood. Early hypotheses emphasized blending of parental traits. Crosses with pure lines: only one trait appeared in next gen. Other trait reappears in a subsequent cross of that gen. Believed that hereditary characteristics are controlled by particles that exist in pairs. Traits (and the genes that govern them) don"t disappear. During gamete formation, pairs of particles randomly separate. During fertilization, members of the pairs are reunited. Half genes come from mother, half come from father. Recombination and crossing over result in daughter cells that are different from each other and parent cell. Gene: a segment of dna that codes for a protein. Locus: the location of a gene on a chromosome. Allele: an alternate form of a gene. Homozygous: two copies of the same allele at a given locus (the only way a recessive gene will be expressed)
