10.1 Genetic History!Don’t be CROSS!!!

For much of human history people were unaware of the scientific details of how babies were conceived and how heredity worked.

Anton van Leeuwenhoek (1632-1723) discovered "animalcules" in the sperm of humans and other animals. Some scientists speculated they saw a "little man" (homunculus) inside each sperm.

Enter Mendel!!!!!!!!!!

Gregor Mendel - "Father" of genetics. - Austrian Monk/Mathmetician - conducted experiments with pea plants, - revealed the basic rules underlying patterns

of inheritance- 1850's + on

Proposed the Particulate Hypothesis: parents pass on to their offspring separate distinct traits.

Mendel proved his theory through his cross fertilization experiments. Pollen from one flower’s pollen fertilizes the egg of another.

1) Mendel's first step was to identify pea plants that were true-breeding. -when self-fertilized, a true-breeding plant produces offspring identical in appearance to itself.

ex: a purple-flowered pea plant when self-fertilized, always produced offspring plants that had purple

flowers. 2)Mendel crossed true-breeding plants that had two distinct and contrasting traits— for example, purple or white flowers. These contrasting pea varieties served as parents for the next generation.