An Introduction To Genetics

  Genetics started with a man named Gregory Mendel, a gardening monk in 1865. He noticed patterns in the generations of plants, and in paticular, 7 traits having to do with pod shape, seed color, height, or the placement and color of flowers. From these, he concluded some of the the basic laws of heridity.
  Next, he noticed how genes didn't blend. He conducted experiments- cross-breeding- and came up with the law of dominance, where one gene is "dominant" over the other, which is "recessive". When he bred those, though, he discovered that the recessive genes reappeared. He had discovered "purebred" and "hybrid" plants, or as we call them, homogeneus or hetreogeneus genes.
Mendel still had not explained how genes reproduced. He hypothesised that sex sells, with only 26 chromesomes, combine to make an offspring with half-and-half of its parents genes. Hundreds of years later, this hypothesis proved correct.
  Mendel's work languish undiscovered until the 1900's, however, because of his abstract and vague writing. Several scientists rediscovered his work and used the recently discovered microscope to try to find one.
  As microscope technology grew, they discovered chromesomes, noodle-like parts of the nuculus of a cell that were made of DNA, deoxyribonucleic acid, or as Mendel called them, genes. They determined your gender, your hair color, your height- everything about you.