01:119:115 Lecture 13: Lecture 13

• School: Rutgers University
• Department: Biological Science
• Course: 01:119:115
• Professor: Stern Cardinale

Document Summary

Today genes are located on chromosomes. chromosomes assort independently: thomas hunt morgan early 20th century experimental embryologist, evidence that chromosomes are the location of mendel"s heritable factors , studied drosophila melanogaster (fruit fly): 4 pairs of chromosomes: 3 pair of autosomes, 1 pair of sex chromosomes. 2 types: wild type, phenotype for character most commonly observed in population, mutant phenotype, alternatives to wild type, ex: white eyes; first mutant found in male. For a given character: gene given symbol 1st mutant ex: allele for: white eyes: w, red eyes: w+ Autosomes: 22 pairs in humans; homomorphic: same shape. Humans + other mammals 2 sex chromosomes: x&y: male: heterogametic, xy genotype, sperm: gets x other get y, y contains sry gene, female: homogametic. Sex determination is not always chromosomal; can vary. Y-linked genes: on the y (few of these: most are related sex determination (sry) X-linked genes: on the x: as many genes as in autosomes, not all determine sex.